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Smith P, Little F, Hermans S, Davies MA, Wood R, Orrell C, Pike C, Peters F, Dube A, Georgeu-Pepper D, Curran R, Fairall L, Bekker LG. A prospective randomised controlled trial investigating household SARS-CoV-2 transmission in a densely populated community in Cape Town, South Africa - the transmission of COVID-19 in crowded environments (TRACE) study. BMC Public Health 2024; 24:1924. [PMID: 39020307 PMCID: PMC11256445 DOI: 10.1186/s12889-024-19462-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 07/12/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND South Africa's first SARS-CoV-2 case was identified 5th March 2020 and national lockdown followed March 26th. Households are an important location for secondary SARS-CoV-2 infection. Physical distancing and sanitation - infection mitigation recommended by the World Health Organization (WHO) at the time - are difficult to implement in limited-resource settings because of overcrowded living conditions. METHODS This study (ClinicalTrials.gov NCT05119348) was conducted from August 2020 to September 2021 in two densely populated, low socioeconomic Cape Town community sub-districts. New COVID-19 index cases (ICs) identified at public clinics were randomised to an infection mitigation intervention (STOPCOV) delivered by lay community health workers (CHWs) or standard of care group. STOPCOV mitigation measures included one initial household assessment conducted by a CHW in which face masks, sanitiser, bleach and written information on managing and preventing spread were provided. This was followed by regular telephonic follow-up from CHWs. SARS-CoV-2 PCR and IgM/IgG serology was performed at baseline, weeks 1, 2, 3 and 4 of follow-up. RESULTS The study randomised 81 ICs with 245 HHCs. At baseline, no HHCs in the control and 7 (5%) in the intervention group had prevalent SARS-CoV-2. The secondary infection rate (SIR) based on SARS-CoV-2 PCR testing was 1.9% (n = 2) in control and 2.9% (n = 4) in intervention HHCs (p = 0.598). At baseline, SARS-CoV-2 antibodies were present in 15% (16/108) of control and 38% (52/137) of intervention participants. At study end incidence was 8.3% (9/108) and 8.03% (11/137) in the intervention and control groups respectively. Antibodies were present in 23% (25/108) of control HHCs over the course of the study vs. 46% (63/137) in the intervention arm. CHWs made twelve clinic and 47 food parcel referrals for individuals in intervention households in need. DISCUSSION Participants had significant exposure to SARS-CoV-2 infections prior to the study. In this setting, household transmission mitigation was ineffective. However, CHWs may have facilitated other important healthcare and social referrals.
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Affiliation(s)
- Philip Smith
- The Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa.
| | - Francesca Little
- Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
| | - Sabine Hermans
- Amsterdam UMC, Department of Global Health, University of Amsterdam, Amsterdam, The Netherlands
- Centre for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam UMC, Amsterdam Institute for Immunology and Infectious Diseases, University of Amsterdam, Amsterdam Public Health - Global Health, Amsterdam, The Netherlands
| | - Mary-Ann Davies
- Center for Infectious Diseases Epidemiology and Research, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- The Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Catherine Orrell
- The Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Carey Pike
- The Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Fatima Peters
- Western Cape Department of Health, Cape Town, South Africa
| | - Audry Dube
- Knowledge Translation Unit, University of Cape Town, Cape Town, South Africa
| | | | - Robyn Curran
- Knowledge Translation Unit, University of Cape Town, Cape Town, South Africa
| | - Lara Fairall
- Knowledge Translation Unit, University of Cape Town, Cape Town, South Africa
| | - Linda-Gail Bekker
- The Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa.
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Trevisi L, Brooks MB, Becerra MC, Calderón RI, Contreras CC, Galea JT, Jimenez J, Lecca L, Yataco RM, Tovar X, Zhang Z, Murray MB, Huang CC. Who Transmits Tuberculosis to Whom: A Cross-Sectional Analysis of a Cohort Study in Lima, Peru. Am J Respir Crit Care Med 2024; 210:222-233. [PMID: 38416532 PMCID: PMC11276835 DOI: 10.1164/rccm.202307-1217oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 02/27/2024] [Indexed: 02/29/2024] Open
Abstract
Rationale: The persistent burden of tuberculosis (TB) disease emphasizes the need to identify individuals with TB for treatment and those at a high risk of incident TB for prevention. Targeting interventions toward those at high risk of developing and transmitting TB is a public health priority. Objectives: We aimed to identify characteristics of individuals involved in TB transmission in a community setting, which may guide the prioritization of targeted interventions. Methods: We collected clinical and sociodemographic data from a cohort of patients with TB in Lima, Peru. We used whole-genome sequencing data to assess the genetic distance between all possible pairs of patients; we considered pairs to be the result of a direct transmission event if they differed by three or fewer SNPs, and we assumed that the first diagnosed patient in a pair was the transmitter and the second was the recipient. We used logistic regression to examine the association between host factors and the likelihood of direct TB transmission. Measurements and Main Results: Analyzing data from 2,518 index patients with TB, we identified 1,447 direct transmission pairs. Regardless of recipient attributes, individuals less than 34 years old, males, and those with a history of incarceration had a higher likelihood of being transmitters in direct transmission pairs. Direct transmission was more likely when both patients were drinkers or smokers. Conclusions: This study identifies men, young adults, former prisoners, alcohol consumers, and smokers as priority groups for targeted interventions. Innovative strategies are needed to extend TB screening to social groups such as young adults and prisoners with limited access to routine preventive care.
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Affiliation(s)
- Letizia Trevisi
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
| | - Meredith B. Brooks
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts
| | - Mercedes C. Becerra
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
- Division of Global Health Equity, Brigham and Women’s Hospital, Boston, Massachusetts
| | | | - Carmen C. Contreras
- Socios en Salud, Lima, Peru
- Harvard Global Health Institute, Cambridge, Massachusetts
| | - Jerome T. Galea
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
- College of Behavioral and Community Sciences, School of Social Work, University of South Florida, Tampa, Florida; and
| | | | - Leonid Lecca
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
- Socios en Salud, Lima, Peru
| | | | - Ximena Tovar
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
| | - Zibiao Zhang
- Division of Global Health Equity, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Megan B. Murray
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
- Division of Global Health Equity, Brigham and Women’s Hospital, Boston, Massachusetts
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Chuan-Chin Huang
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts
- Division of Global Health Equity, Brigham and Women’s Hospital, Boston, Massachusetts
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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Kakande E, Ssekyanzi B, Abbott R, Ariho W, Nattabi G, Landsiedel K, Temple J, Chamie G, Havlir DV, Kamya MR, Charlebois ED, Balzer LB, Marquez C. Prevalence and Predictors of Tuberculosis Infection in Children and Adolescents in Rural Uganda: A Cross-sectional Study. Pediatr Infect Dis J 2024:00006454-990000000-00946. [PMID: 39018476 DOI: 10.1097/inf.0000000000004475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/19/2024]
Abstract
BACKGROUND Much of the latent tuberculosis (TB) reservoir is established in childhood and adolescence. Yet, age-specific data on prevalence and predictors of infection in this population are sparse and needed to guide prevention and case finding. METHODS From December 2021 to June 2023, we measured TB infection in children 1-17 years in 25 villages in rural Southwestern Uganda. We defined TB infection as a positive QuantiFERON Gold Plus Test (QFT). We estimated overall and age-stratified population-level prevalence and adjusted risk ratios (aRR) of TB infection for individual, household, and community-based predictors, accounting for age, TB contact, and clustering by household. RESULTS Estimated TB infection prevalence was 9.6% [95% confidence interval (CI): 8.7-10.5%] among the 5789 participants, and prevalence varied slightly with age. Household-level risk factors included crowding (aRR: 1.25, 95% CI: 1.03-1.53), indoor cooking (aRR: 1.62, 95% CI: 1.14-2.30), living with ≥2 persons who drink alcohol (aRR: 1.47, 95% CI: 1.04-2.07). The predominant community-based risk factor was child mobility (aRR: 1.67, 95% CI: 1.24-2.26). In age-stratified analyses, household predictors were important in early childhood but not adolescence, where mobility was predominant (aRR: 1.66, 95% CI: 1.13-2.44). CONCLUSION We detected a high prevalence of TB infection in children and adolescents in rural Uganda. On a population level, TB risk factors change throughout the early life course, with child mobility a key risk factor in adolescence. Age-specific TB case finding and prevention strategies that address both household and extra-household risk factors are needed to address TB transmission.
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Affiliation(s)
- Elijah Kakande
- From the Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Bob Ssekyanzi
- From the Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Rachel Abbott
- Department of Medicine, Division of HIV, ID and Global Medicine, University of California, San Francisco, California
| | - Willington Ariho
- From the Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Gloria Nattabi
- From the Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Kirsten Landsiedel
- Division of Biostatistics, University of California, Berkeley, Berkeley, California
| | - Jennifer Temple
- Department of Medicine, Division of HIV, ID and Global Medicine, University of California, San Francisco, California
| | - Gabriel Chamie
- Department of Medicine, Division of HIV, ID and Global Medicine, University of California, San Francisco, California
| | - Diane V Havlir
- Department of Medicine, Division of HIV, ID and Global Medicine, University of California, San Francisco, California
| | - Moses R Kamya
- From the Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, School of Medicine, Makerere University, Kampala, Uganda
| | - Edwin D Charlebois
- Department of Medicine, Center for AIDS Prevention Studies, Division of Prevention Science, University of California, San Francisco, San Francisco, California
| | - Laura B Balzer
- Division of Biostatistics, University of California, Berkeley, Berkeley, California
| | - Carina Marquez
- Department of Medicine, Division of HIV, ID and Global Medicine, University of California, San Francisco, California
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Aguolu OG, Kiti MC, Nelson K, Liu CY, Sundaram M, Gramacho S, Jenness S, Melegaro A, Sacoor C, Bardaji A, Macicame I, Jose A, Cavele N, Amosse F, Uamba M, Jamisse E, Tchavana C, Giovanni Maldonado Briones H, Jarquín C, Ajsivinac M, Pischel L, Ahmed N, Mohan VR, Srinivasan R, Samuel P, John G, Ellington K, Augusto Joaquim O, Zelaya A, Kim S, Chen H, Kazi M, Malik F, Yildirim I, Lopman B, Omer SB. Comprehensive profiling of social mixing patterns in resource poor countries: A mixed methods research protocol. PLoS One 2024; 19:e0301638. [PMID: 38913670 PMCID: PMC11195963 DOI: 10.1371/journal.pone.0301638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 03/15/2024] [Indexed: 06/26/2024] Open
Abstract
BACKGROUND Low-and-middle-income countries (LMICs) bear a disproportionate burden of communicable diseases. Social interaction data inform infectious disease models and disease prevention strategies. The variations in demographics and contact patterns across ages, cultures, and locations significantly impact infectious disease dynamics and pathogen transmission. LMICs lack sufficient social interaction data for infectious disease modeling. METHODS To address this gap, we will collect qualitative and quantitative data from eight study sites (encompassing both rural and urban settings) across Guatemala, India, Pakistan, and Mozambique. We will conduct focus group discussions and cognitive interviews to assess the feasibility and acceptability of our data collection tools at each site. Thematic and rapid analyses will help to identify key themes and categories through coding, guiding the design of quantitative data collection tools (enrollment survey, contact diaries, exit survey, and wearable proximity sensors) and the implementation of study procedures. We will create three age-specific contact matrices (physical, nonphysical, and both) at each study site using data from standardized contact diaries to characterize the patterns of social mixing. Regression analysis will be conducted to identify key drivers of contacts. We will comprehensively profile the frequency, duration, and intensity of infants' interactions with household members using high resolution data from the proximity sensors and calculating infants' proximity score (fraction of time spent by each household member in proximity with the infant, over the total infant contact time) for each household member. DISCUSSION Our qualitative data yielded insights into the perceptions and acceptability of contact diaries and wearable proximity sensors for collecting social mixing data in LMICs. The quantitative data will allow a more accurate representation of human interactions that lead to the transmission of pathogens through close contact in LMICs. Our findings will provide more appropriate social mixing data for parameterizing mathematical models of LMIC populations. Our study tools could be adapted for other studies.
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Affiliation(s)
- Obianuju Genevieve Aguolu
- Division of Epidemiology, College of Public Heath, The Ohio State University, Columbus, Ohio, United States of America
| | - Moses Chapa Kiti
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Kristin Nelson
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Carol Y. Liu
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Maria Sundaram
- Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, Wisconsin, United States of America
| | - Sergio Gramacho
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Samuel Jenness
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Alessia Melegaro
- DONDENA Centre for Research in Social Dynamics and Public Policy, Bocconi University, Milan, Italy
| | | | - Azucena Bardaji
- Manhiça Health Research Centre, Manhica, Mozambique
- ISGlobal, Hospital Clinic–Universitat de Barcelona, Barcelona, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Ivalda Macicame
- Polana Caniço Health Research and Training Centre, CISPOC, Maputo, Mozambique
| | - Americo Jose
- Polana Caniço Health Research and Training Centre, CISPOC, Maputo, Mozambique
| | - Nilzio Cavele
- Polana Caniço Health Research and Training Centre, CISPOC, Maputo, Mozambique
| | | | - Migdalia Uamba
- Polana Caniço Health Research and Training Centre, CISPOC, Maputo, Mozambique
| | | | | | | | - Claudia Jarquín
- Centro de Estudios en Salud (CES), Universidad del Valle de Guatemala, Guatemala City, Guatemala
| | - María Ajsivinac
- Centro de Estudios en Salud (CES), Universidad del Valle de Guatemala, Guatemala City, Guatemala
| | - Lauren Pischel
- Yale School of Medicine, Yale University, New Haven, Connecticut, United States of America
| | - Noureen Ahmed
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas, United States of America
| | | | | | | | - Gifta John
- Christian Medical College Vellore, Vellore, India
| | - Kye Ellington
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | | | - Alana Zelaya
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Sara Kim
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Holin Chen
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Momin Kazi
- The Aga Khan University, Karachi, Pakistán
| | - Fauzia Malik
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas, United States of America
| | - Inci Yildirim
- Yale School of Medicine, Yale University, New Haven, Connecticut, United States of America
| | - Benjamin Lopman
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Saad B. Omer
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas, United States of America
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Yates TA, Cebekhulu S, Mthethwa M, Fourie PB, Newell ML, Abubakar I, Tanser F. Tuberculin skin test surveys and the Annual Risk of Tuberculous Infection in school children in Northern KwaZulu-Natal. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0003263. [PMID: 38889188 PMCID: PMC11185501 DOI: 10.1371/journal.pgph.0003263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 04/29/2024] [Indexed: 06/20/2024]
Abstract
Tuberculin skin test surveys in primary school children can be used to quantify Mycobacterium tuberculosis transmission at community level. KwaZulu-Natal province, South Africa, is home to 11.5 million people and suffers a burden of tuberculosis disease that is among the highest in the world. The last tuberculin survey in the province was undertaken in 1979. We performed a tuberculin skin test survey nested within a demographic and health household surveillance programme in Northern KwaZulu-Natal. We enrolled children aged between six and eight years of age attending primary schools in this community. Mixture analysis was used to determine tuberculin skin test thresholds and the Annual Risk of Tuberculous Infection derived from age at testing and infection prevalence. The Community Infection Ratio, a measure of the relative importance of within-household and community transmission, was calculated from data on tuberculin positivity disaggregated by household tuberculosis contact. Between June and December 2013, we obtained tuberculin skin test results on 1240 children. Mixture analysis proved unstable, suggesting two potential thresholds for test positivity. Using a threshold of ≥10mm or treating all non zero reactions as positive yielded estimates of the Annual Risk of Tuberculous Infection of 1.7% (1.4-2.1%) or 2.4% (2.0-3.0%). Using the same thresholds and including children reported to be receiving TB treatment as cases, resulted in estimates of 2.0% (1.6-2.5%) or 2.7% (2.2-3.3%). The Community Infection Ratio was 0.58 (0.33-1.01). The force of infection in this community is lower than that observed in Western Cape province, South Africa, but higher than that observed in community settings in most other parts of the world. Children in this community are commonly infected with Mycobacterium tuberculosis outside the home. Interventions to interrupt transmission are urgently needed.
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Affiliation(s)
- Tom A. Yates
- Africa Health Research Institute (AHRI), Congella, South Africa
- Institute of Health Informatics, University College London, London, United Kingdom
- Division of Infection and Immunity, University College London, London, United Kingdom
| | | | - Mumsy Mthethwa
- Africa Health Research Institute (AHRI), Congella, South Africa
| | - P. Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - Marie-Louise Newell
- School of Human Development and Health University of Southampton, Southampton, United Kingdom
| | - Ibrahim Abubakar
- Faculty of Population Health Sciences, University College London, London, United Kingdom
- MRC Clinical Trials Unit, University College London, London, United Kingdom
| | - Frank Tanser
- Africa Health Research Institute (AHRI), Congella, South Africa
- Centre for Epidemic Response and Innovation (CERI), Stellenbosch University, Stellenbosch, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of Kwa-Zulu Natal, Congella, South Africa
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Dall’Amico L, Kleynhans J, Gauvin L, Tizzoni M, Ozella L, Makhasi M, Wolter N, Language B, Wagner RG, Cohen C, Tempia S, Cattuto C. Estimating household contact matrices structure from easily collectable metadata. PLoS One 2024; 19:e0296810. [PMID: 38483886 PMCID: PMC10939291 DOI: 10.1371/journal.pone.0296810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/18/2023] [Indexed: 03/17/2024] Open
Abstract
Contact matrices are a commonly adopted data representation, used to develop compartmental models for epidemic spreading, accounting for the contact heterogeneities across age groups. Their estimation, however, is generally time and effort consuming and model-driven strategies to quantify the contacts are often needed. In this article we focus on household contact matrices, describing the contacts among the members of a family and develop a parametric model to describe them. This model combines demographic and easily quantifiable survey-based data and is tested on high resolution proximity data collected in two sites in South Africa. Given its simplicity and interpretability, we expect our method to be easily applied to other contexts as well and we identify relevant questions that need to be addressed during the data collection procedure.
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Affiliation(s)
| | - Jackie Kleynhans
- National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Laetitia Gauvin
- ISI Foundation, Turin, Italy
- Institute for Research on sustainable Development, UMR215 PRODIG, Aubervilliers, France
| | - Michele Tizzoni
- ISI Foundation, Turin, Italy
- Department of Sociology and Social Research, University of Trento, Trento, Italy
| | | | - Mvuyo Makhasi
- National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Nicole Wolter
- National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Brigitte Language
- Unit for Environmental Science and Management, Climatology Research Group, North-West University, Potchefstroom, South Africa
| | - Ryan G. Wagner
- MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), Agincourt, South Africa
| | - Cheryl Cohen
- National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Stefano Tempia
- National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Ciro Cattuto
- ISI Foundation, Turin, Italy
- Department of Informatics, University of Turin, Turin, Italy
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7
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Kim MK, Bhattacharya J, Bhattacharya J. Is income inequality linked to infectious disease prevalence? A hypothesis-generating study using tuberculosis. Soc Sci Med 2024; 345:116639. [PMID: 38364719 DOI: 10.1016/j.socscimed.2024.116639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/18/2024]
Abstract
We study the association between infectious disease incidence and income inequality. We hypothesize that random social mixing in an income-unequal society brings into contact a) susceptible and infected poor and b) the infected-poor and the susceptible-rich, raising infectious disease incidence. We analyzed publicly available, country-level panel data for a large cross-section of countries between 1995 and 2013 to examine whether countries with elevated levels of income inequality have higher rates of pulmonary Tuberculosis (TB) incidence per capita. A "negative control" using anemia and diabetes (both non-communicable diseases and hence impervious to the hypothesized mechanism) is also applied. We find that high levels of income inequality are positively associated with tuberculosis incidence. All else equal, countries with income-Gini coefficients 10% apart show a statistically significant 4% difference in tuberculosis incidence. Income inequality had a null effect on the negative controls. Our cross-country regression results suggest that income inequality may create conditions where TB spreads more easily, and policy action to reduce income inequities could directly contribute to a reduced TB burden.
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8
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Aguolu OG, Kiti MC, Nelson K, Liu CY, Sundaram M, Gramacho S, Jenness S, Melegaro A, Sacoor C, Bardaji A, Macicame I, Jose A, Cavele N, Amosse F, Uamba M, Jamisse E, Tchavana C, Briones HGM, Jarquín C, Ajsivinac M, Pischel L, Ahmed N, Mohan VR, Srinivasan R, Samuel P, John G, Ellington K, Joaquim OA, Zelaya A, Kim S, Chen H, Kazi M, Malik F, Yildirim I, Lopman B, Omer SB. Comprehensive profiling of social mixing patterns in resource poor countries: a mixed methods research protocol. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.05.23299472. [PMID: 38105989 PMCID: PMC10723497 DOI: 10.1101/2023.12.05.23299472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Background Low-and-middle-income countries (LMICs) bear a disproportionate burden of communicable diseases. Social interaction data inform infectious disease models and disease prevention strategies. The variations in demographics and contact patterns across ages, cultures, and locations significantly impact infectious disease dynamics and pathogen transmission. LMICs lack sufficient social interaction data for infectious disease modeling. Methods To address this gap, we will collect qualitative and quantitative data from eight study sites (encompassing both rural and urban settings) across Guatemala, India, Pakistan, and Mozambique. We will conduct focus group discussions and cognitive interviews to assess the feasibility and acceptability of our data collection tools at each site. Thematic and rapid analyses will help to identify key themes and categories through coding, guiding the design of quantitative data collection tools (enrollment survey, contact diaries, exit survey, and wearable proximity sensors) and the implementation of study procedures.We will create three age-specific contact matrices (physical, nonphysical, and both) at each study site using data from standardized contact diaries to characterize the patterns of social mixing. Regression analysis will be conducted to identify key drivers of contacts. We will comprehensively profile the frequency, duration, and intensity of infants' interactions with household members using high resolution data from the proximity sensors and calculating infants' proximity score (fraction of time spent by each household member in proximity with the infant, over the total infant contact time) for each household member. Discussion Our qualitative data yielded insights into the perceptions and acceptability of contact diaries and wearable proximity sensors for collecting social mixing data in LMICs. The quantitative data will allow a more accurate representation of human interactions that lead to the transmission of pathogens through close contact in LMICs. Our findings will provide more appropriate social mixing data for parameterizing mathematical models of LMIC populations. Our study tools could be adapted for other studies.
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Affiliation(s)
| | | | - Kristin Nelson
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Carol Y. Liu
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Maria Sundaram
- Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | - Sergio Gramacho
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Samuel Jenness
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Alessia Melegaro
- DONDENA Centre for Research in Social Dynamics and Public Policy, Bocconi University, Italy
| | | | - Azucena Bardaji
- Manhiça Health Research Centre, Manhica, Mozambique
- ISGlobal, Hospital Clinic – Universitat de Barcelona, Barcelona, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Ivalda Macicame
- Polana Caniço Health Research and Training Centre, CISPOC, Mozambique
| | - Americo Jose
- Polana Caniço Health Research and Training Centre, CISPOC, Mozambique
| | - Nilzio Cavele
- Polana Caniço Health Research and Training Centre, CISPOC, Mozambique
| | | | - Migdalia Uamba
- Polana Caniço Health Research and Training Centre, CISPOC, Mozambique
| | | | | | | | - Claudia Jarquín
- Centro de Estudios en Salud (CES), Universidad del Valle de Guatemala
| | - María Ajsivinac
- Centro de Estudios en Salud (CES), Universidad del Valle de Guatemala
| | - Lauren Pischel
- Yale School of Medicine, Yale University, Connecticut, USA
| | - Noureen Ahmed
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas
| | | | | | | | - Gifta John
- Christian Medical College Vellore, India
| | - Kye Ellington
- Rollins School of Public Health, Emory University, Georgia, USA
| | | | - Alana Zelaya
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Sara Kim
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Holin Chen
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Momin Kazi
- The Aga Khan University, Karachi, Pakistán
| | - Fauzia Malik
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas
| | - Inci Yildirim
- Yale School of Medicine, Yale University, Connecticut, USA
| | - Benjamin Lopman
- Rollins School of Public Health, Emory University, Georgia, USA
| | - Saad B. Omer
- Peter O’Donnell Jr. School of Public Health at UT Southwestern Medical Center, Dallas, Texas
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9
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Kraft TS, Seabright E, Alami S, Jenness SM, Hooper P, Beheim B, Davis H, Cummings DK, Rodriguez DE, Cayuba MG, Miner E, de Lamballerie X, Inchauste L, Priet S, Trumble BC, Stieglitz J, Kaplan H, Gurven MD. Metapopulation dynamics of SARS-CoV-2 transmission in a small-scale Amazonian society. PLoS Biol 2023; 21:e3002108. [PMID: 37607188 PMCID: PMC10443873 DOI: 10.1371/journal.pbio.3002108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/17/2023] [Indexed: 08/24/2023] Open
Abstract
The severity of infectious disease outbreaks is governed by patterns of human contact, which vary by geography, social organization, mobility, access to technology and healthcare, economic development, and culture. Whereas globalized societies and urban centers exhibit characteristics that can heighten vulnerability to pandemics, small-scale subsistence societies occupying remote, rural areas may be buffered. Accordingly, voluntary collective isolation has been proposed as one strategy to mitigate the impacts of COVID-19 and other pandemics on small-scale Indigenous populations with minimal access to healthcare infrastructure. To assess the vulnerability of such populations and the viability of interventions such as voluntary collective isolation, we simulate and analyze the dynamics of SARS-CoV-2 infection among Amazonian forager-horticulturalists in Bolivia using a stochastic network metapopulation model parameterized with high-resolution empirical data on population structure, mobility, and contact networks. Our model suggests that relative isolation offers little protection at the population level (expected approximately 80% cumulative incidence), and more remote communities are not conferred protection via greater distance from outside sources of infection, due to common features of small-scale societies that promote rapid disease transmission such as high rates of travel and dense social networks. Neighborhood density, central household location in villages, and household size greatly increase the individual risk of infection. Simulated interventions further demonstrate that without implausibly high levels of centralized control, collective isolation is unlikely to be effective, especially if it is difficult to restrict visitation between communities as well as travel to outside areas. Finally, comparison of model results to empirical COVID-19 outcomes measured via seroassay suggest that our theoretical model is successful at predicting outbreak severity at both the population and community levels. Taken together, these findings suggest that the social organization and relative isolation from urban centers of many rural Indigenous communities offer little protection from pandemics and that standard control measures, including vaccination, are required to counteract effects of tight-knit social structures characteristic of small-scale populations.
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Affiliation(s)
- Thomas S. Kraft
- Department of Anthropology, University of Utah, Salt Lake City, Utah, United States of America
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, California, United States of America
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Edmond Seabright
- School of Collective Intelligence, Mohammed VI Polytechnic University, Rabat, Morocco
- University of New Mexico, Department of Anthropology, Albuquerque, New Mexico, United States of America
| | - Sarah Alami
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, California, United States of America
- School of Collective Intelligence, Mohammed VI Polytechnic University, Rabat, Morocco
| | - Samuel M. Jenness
- Department of Epidemiology, Emory University, Atlanta, Georgia, United States of America
| | - Paul Hooper
- Department of Health Economics and Anthropology, Economic Science Institute, Argyros School of Business and Economics, Chapman University, Orange, California, United States of America
| | - Bret Beheim
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Helen Davis
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Daniel K. Cummings
- Department of Health Economics and Anthropology, Economic Science Institute, Argyros School of Business and Economics, Chapman University, Orange, California, United States of America
| | | | | | - Emily Miner
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Xavier de Lamballerie
- Unité des Virus Émergents (UVE: Aix-Marseille Univ–IRD 190 –Inserm 1207 –IHU Méditerranée Infection), Marseille, France
| | - Lucia Inchauste
- Unité des Virus Émergents (UVE: Aix-Marseille Univ–IRD 190 –Inserm 1207 –IHU Méditerranée Infection), Marseille, France
| | - Stéphane Priet
- Unité des Virus Émergents (UVE: Aix-Marseille Univ–IRD 190 –Inserm 1207 –IHU Méditerranée Infection), Marseille, France
| | - Benjamin C. Trumble
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
- Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, United States of America
| | | | - Hillard Kaplan
- Department of Health Economics and Anthropology, Economic Science Institute, Argyros School of Business and Economics, Chapman University, Orange, California, United States of America
| | - Michael D. Gurven
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, California, United States of America
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10
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Chiang SS, Senador L, Altamirano E, Wong M, Beckhorn CB, Roche S, Coit J, Oliva Rapoport VE, Lecca L, Galea JT. Adolescent, caregiver and provider perspectives on tuberculosis treatment adherence: a qualitative study from Lima, Peru. BMJ Open 2023; 13:e069938. [PMID: 37202135 PMCID: PMC10201266 DOI: 10.1136/bmjopen-2022-069938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/09/2023] [Indexed: 05/20/2023] Open
Abstract
OBJECTIVES To understand the perspectives of adolescents (10-19 years old), their caregivers and healthcare providers regarding factors that impact adherence to tuberculosis (TB) treatment among adolescents. DESIGN We conducted in-depth interviews using semistructured interview guides based on the World Health Organization (WHO)'s Five Dimensions of Adherence framework, which conceptualises adherence as being related to the health system, socioeconomic factors, patient, treatment and condition. We applied framework thematic analysis. SETTING Between August 2018 and May 2019, at 32 public health centres operated by the Ministry of Health in Lima, Peru. PARTICIPANTS We interviewed 34 adolescents who completed or were lost to follow-up from treatment for drug-susceptible pulmonary TB disease in the preceding 12 months; their primary caregiver during treatment; and 15 nurses or nurse technicians who had ≥6 months' experience supervising TB treatment. RESULTS Participants reported numerous treatment barriers, the most common of which were the inconvenience of health facility-based directly observed therapy (DOT), long treatment duration, adverse treatment events and symptom resolution. The support of adult caregivers was critical for helping adolescents overcome these barriers and carry out the behavioural skills (eg, coping with the large pill burden, managing adverse treatment events and incorporating treatment into daily routines) needed to adhere to treatment. CONCLUSION Our findings support a three-pronged approach to improve TB treatment adherence among adolescents: (1) reduce barriers to adherence (eg, home-based or community-based DOT in lieu of facility-based DOT, reducing pill burden and treatment duration when appropriate), (2) teach adolescents the behavioural skills required for treatment adherence and (3) strengthen caregivers' ability to support adolescents.
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Affiliation(s)
- Silvia S Chiang
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
- Center for International Health Research, Rhode Island Hospital, Providence, Rhode Island, USA
| | | | | | | | | | - Stephanie Roche
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Institute, Seattle, Washington, USA
| | - Julia Coit
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Leonid Lecca
- Socios En Salud Sucursal Peru, Lima, Peru
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Jerome T Galea
- Department of Social Work, University of South Florida, Tampa, Florida, USA
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11
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Leung WTM, Meeyai A, Holt HR, Khieu B, Chhay T, Seng S, Pok S, Chiv P, Drake T, Rudge JW. Social contact patterns relevant for infectious disease transmission in Cambodia. Sci Rep 2023; 13:5542. [PMID: 37015945 PMCID: PMC10072808 DOI: 10.1038/s41598-023-31485-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 03/13/2023] [Indexed: 04/06/2023] Open
Abstract
Social mixing patterns are key determinants of infectious disease transmission. Mathematical models parameterised with empirical data from contact pattern surveys have played an important role in understanding epidemic dynamics and informing control strategies, including for SARS-CoV-2. However, there is a paucity of data on social mixing patterns in many settings. We conducted a community-based survey in Cambodia in 2012 to characterise mixing patterns and generate setting-specific contact matrices according to age and urban/rural populations. Data were collected using a diary-based approach from 2016 participants, selected by stratified random sampling. Contact patterns were highly age-assortative, with clear intergenerational mixing between household members. Both home and school were high-intensity contact settings, with 27.7% of contacts occurring at home with non-household members. Social mixing patterns differed between rural and urban residents; rural participants tended to have more intergenerational mixing, and a higher number of contacts outside of home, work or school. Participants had low spatial mobility, with 88% of contacts occurring within 1 km of the participants' homes. These data broaden the evidence-base on social mixing patterns in low and middle-income countries and Southeast Asia, and highlight within-country heterogeneities which may be important to consider when modelling the dynamics of pathogens transmitted via close contact.
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Affiliation(s)
- William T M Leung
- Communicable Diseases Policy Research Group, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - Aronrag Meeyai
- Communicable Diseases Policy Research Group, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
- Department of Epidemiology, Faculty of Mahidol Public Health, Mahidol University, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Hannah R Holt
- Communicable Diseases Policy Research Group, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK.
| | - Borin Khieu
- Livestock Development for Community Livelihood Organization, St 181, Phnom Penh, Cambodia
| | - Ty Chhay
- Livestock Development for Community Livelihood Organization, St 181, Phnom Penh, Cambodia
| | - Sokeyra Seng
- Livestock Development for Community Livelihood Organization, St 181, Phnom Penh, Cambodia
| | - Samkol Pok
- Livestock Development for Community Livelihood Organization, St 181, Phnom Penh, Cambodia
- National Institute of Science, Technology and Innovation, Ministry of Industry, Science, Technology and Innovation, National Road 2, Phnom Penh, Cambodia
| | - Phiny Chiv
- Livestock Development for Community Livelihood Organization, St 181, Phnom Penh, Cambodia
| | - Tom Drake
- Communicable Diseases Policy Research Group, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - James W Rudge
- Communicable Diseases Policy Research Group, Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
- Department of Epidemiology, Faculty of Mahidol Public Health, Mahidol University, Bangkok, 10400, Thailand
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12
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Chiang SS, Waterous PM, Atieno VF, Bernays S, Bondarenko Y, Cruz AT, de Oliveira MCB, Del Castillo Barrientos H, Enimil A, Ferlazzo G, Ferrand RA, Furin J, Hoddinott G, Isaakidis P, Kranzer K, Maleche-Obimbo E, Mansoor H, Marais BJ, Mohr-Holland E, Morales M, Nguyen AP, Oliyo JO, Sant'Anna CC, Sawyer SM, Schaaf HS, Seddon JA, Sharma S, Skrahina A, Starke JR, Triasih R, Tsogt B, Welch H, Enane LA. Caring for Adolescents and Young Adults With Tuberculosis or at Risk of Tuberculosis: Consensus Statement From an International Expert Panel. J Adolesc Health 2023; 72:323-331. [PMID: 36803849 PMCID: PMC10265598 DOI: 10.1016/j.jadohealth.2022.10.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 10/25/2022] [Indexed: 02/19/2023]
Abstract
Background: Despite being a preventable and treatable disease, tuberculosis (TB) is a leading cause of death among young people globally. Each year, an estimated 1.8 million adolescents and young adults (AYAs; 10–24 years old) develop TB. In 2019, an estimated 161,000 AYAs died of the disease. AYAs have unique developmental, psychosocial, and healthcare needs, but these needs have been neglected in both TB care and research agendas. In order to improve outcomes in this age group, the specific needs of AYAs must be considered and addressed. Methods: Through a consensus process, an international panel of 34 clinicians, researchers, TB survivors, and advocates with expertise in child/adolescent TB and/or adolescent health proposed interventions for optimizing AYA engagement in TB care. The process consisted of reviewing the literature on TB in AYAs; identifying and discussing priority areas; and drafting and revising proposed interventions until consensus, defined a priori , was reached. Results: The panel acknowledged the dearth of evidence on best practices for identifying and managing AYAs with TB. The final consensus statement, based on expert opinion, proposes nine interventions to reform current practices that may harm AYA health and well-being, and nine interventions to establish high-quality AYA-centered TB services. Conclusion: AYA-specific interventions for TB care and research are critical for improving outcomes in this age group. In the absence of evidence on best practices, this consensus statement from an international group of experts can help address the needs of AYA with TB or at risk for TB.
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Affiliation(s)
- Silvia S Chiang
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Alpert Medical School of Brown University, Providence, Rhode Island; Center for International Health Research, Rhode Island Hospital, Providence, Rhode Island.
| | - Patricia M Waterous
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Sarah Bernays
- School of Public Health, University of Sydney, Sydney, Australia; Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Yaroslava Bondarenko
- Department of Phthisiology and Pulmonology, Bogomolets National Medical University, Kyiv, Ukraine
| | - Andrea T Cruz
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Márcia C B de Oliveira
- Department of Pediatrics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Department of Pediatrics, Souza Marques School of Medicine, Rio de Janeiro, Brazil
| | | | - Anthony Enimil
- Child Health Department, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Child Health Directorate, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Gabriella Ferlazzo
- Médecins Sans Frontières, Cape Town, South Africa; Médecins Sans Frontières, Mumbai, India
| | - Rashida Abbas Ferrand
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom; Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Jennifer Furin
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts; Sentinel Project on Pediatric Drug-Resistant Tuberculosis, Boston, Massachusetts
| | - Graeme Hoddinott
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Stellenbosch University, Cape Town, South Africa
| | - Petros Isaakidis
- Médecins Sans Frontières, Cape Town, South Africa; Médecins Sans Frontières, Mumbai, India
| | - Katharina Kranzer
- School of Public Health, University of Sydney, Sydney, Australia; Biomedical Research and Training Institute, Harare, Zimbabwe
| | | | | | - Ben J Marais
- Sydney Infectious Diseases Institute (Sydney ID), University of Sydney, Sydney, Australia; Department of Infectious Diseases and Microbiology, The Children's Hospital at Westmead, Sydney, Australia
| | | | | | | | | | - Clemax Couto Sant'Anna
- Department of Pediatrics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susan M Sawyer
- Centre for Adolescent Health, Royal Children's Hospital and Murdoch Children's Research Institute, Melbourne, Australia; Department of Peadiatrics, The University of Melbourne, Melbourne, Australia
| | - H Simon Schaaf
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Stellenbosch University, Cape Town, South Africa
| | - James A Seddon
- Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Stellenbosch University, Cape Town, South Africa; Department of Infectious Diseases, Imperial College London, London, United Kingdom
| | - Sangeeta Sharma
- Department of Paediatrics, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India
| | - Alena Skrahina
- Clinical Department, The Republican Research and Practica Centre for Pulmonology and TB, Minsk, Belarus
| | - Jeffrey R Starke
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Rina Triasih
- Department of Pediatrics, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, Indonesia
| | | | - Henry Welch
- Department of Pediatrics, Souza Marques School of Medicine, Rio de Janeiro, Brazil; Department of Pediatrics, School of Medicine and Health Sciences, The University of Papua New Guinea, Port Moresby, Papua New Guinea; Port Moresby General Hospital, Port Moresby, Papua New Guinea
| | - Leslie A Enane
- Department of Pediatrics, The Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University School of Medicine, Indianapolis, Indiana; Indiana University Center for Global Health, Indianapolis, Indiana.
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13
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Sewpaul R, Mabaso M, Cloete A, Dukhi N, Naidoo I, Davids AS, Mokhele T, Zuma K, Reddy SP. Social distancing behaviour: avoidance of physical contact and related determinants among South Africans: twelve days into the COVID-19 lockdown. PSYCHOL HEALTH MED 2023; 28:260-278. [PMID: 35549779 DOI: 10.1080/13548506.2022.2075020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Social distancing behaviour is a primary preventive measure for reducing COVID-19 transmission. Improved understanding of factors associated with adherence to social distancing is vital for mitigating the impact of COVID-19 in South Africa. The study assessed adherence to social distancing and its associated factors during the state-implemented lockdown in South Africa. Data was analysed from a large-scale public survey conducted in South Africa from 8 to 29 April 2020, which was administered online and telephonically. Invitations to participate were distributed widely on local websites and social media networks, including on a data-free platform. Adherence to social distancing was measured by self-report of having engaged in close physical contact with someone outside the home. Simple and multiple logistic regression models examined the association between social distancing and potential explanatory variables. Of the 17,586 participants, 9.2% came into close physical contact with a person outside their home by hugging, kissing, or shaking hands during the past 7 days. The odds of coming into close physical contact with other people were significantly higher for males, students, and those with incorrect knowledge on physical distancing, angry attitudes about the lockdown, lack of confidence in the government response, high-risk perception, movement out of the local area, travelling to shops using public transport, households with communal water facilities and higher household size. The 25-59-year olds compared to 18-24-year olds, and the White and Indian/Asian compared to the African population groups had significantly lower odds of close physical contact with others outside the home. The study identifies subgroups of individuals for whom public health interventions to improve adherence to social distancing should be prioritised and tailored. Interventions and policies should take cognisance of the social determinants of health as well as culturally accepted greeting practices like hand shaking.
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Affiliation(s)
- Ronel Sewpaul
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Musawenkosi Mabaso
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Allanise Cloete
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Natisha Dukhi
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Inbarani Naidoo
- Human Sciences Research Council, Centre for Community Based Research, Human and Social Capabilities, Pietermaritzburg, South Africa
| | - Adlai S Davids
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa.,Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa
| | - Tholang Mokhele
- Human Sciences Research Council, eKnowledge Research Centre, Pretoria, South Africa
| | - Khangelani Zuma
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa
| | - Sasiragha Priscilla Reddy
- Human and Social Capabilities Division, Human Sciences Research Council, Cape Town, South Africa.,Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa
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14
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van Zandvoort K, Bobe MO, Hassan AI, Abdi MI, Ahmed MS, Soleman SM, Warsame MY, Wais MA, Diggle E, McGowan CR, Satzke C, Mulholland K, Egeh MM, Hassan MM, Hergeeye MA, Eggo RM, Checchi F, Flasche S. Social contacts and other risk factors for respiratory infections among internally displaced people in Somaliland. Epidemics 2022; 41:100625. [PMID: 36103782 DOI: 10.1016/j.epidem.2022.100625] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/16/2022] [Accepted: 08/25/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Populations affected by humanitarian crises experience high burdens of acute respiratory infections (ARI), potentially driven by risk factors for severe disease such as poor nutrition and underlying conditions, and risk factors that may increase transmission such as overcrowding and the possibility of high social mixing. However, little is known about social mixing patterns in these populations. METHODS We conducted a cross-sectional social contact survey among internally displaced people (IDP) living in Digaale, a permanent IDP camp in Somaliland. We included questions on household demographics, shelter quality, crowding, travel frequency, health status, and recent diagnosis of pneumonia, and assessed anthropometric status in children. We present the prevalence of several risk factors relevant to transmission of respiratory infections, and calculated age-standardised social contact matrices to assess population mixing. RESULTS We found crowded households with high proportions of recent self-reported pneumonia (46% in children). 20% of children younger than five are stunted, and crude death rates are high in all age groups. ARI risk factors were common. Participants reported around 10 direct contacts per day. Social contact patterns are assortative by age, and physical contact rates are very high (78%). CONCLUSIONS ARI risk factors are very common in this population, while the large degree of contacts that involve physical touch could further increase transmission. Such IDP settings potentially present a perfect storm of risk factors for ARIs and their transmission, and innovative approaches to address such risks are urgently needed.
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Affiliation(s)
- Kevin van Zandvoort
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
| | - Mohamed Omer Bobe
- Save the Children International, Maansoor area, Jig-jiga yar, Hargeisa, Somaliland
| | - Abdirahman Ibrahim Hassan
- Republic of Somaliland Ministry of Health Development, 26 June District, Presidential Road, Hargeisa, Somaliland
| | - Mohamed Ismail Abdi
- Save the Children International, Maansoor area, Jig-jiga yar, Hargeisa, Somaliland
| | - Mohammed Saed Ahmed
- Save the Children International, Maansoor area, Jig-jiga yar, Hargeisa, Somaliland
| | - Saeed Mohamood Soleman
- Republic of Somaliland Ministry of Health Development, 26 June District, Presidential Road, Hargeisa, Somaliland
| | - Mohamed Yusuf Warsame
- Republic of Somaliland Ministry of Health Development, 26 June District, Presidential Road, Hargeisa, Somaliland
| | - Muna Awil Wais
- Save the Children International, Maansoor area, Jig-jiga yar, Hargeisa, Somaliland
| | - Emma Diggle
- Save the Children UK, 1 St John's Lane, London EC1M 4AR, United Kingdom
| | - Catherine R McGowan
- Save the Children UK, 1 St John's Lane, London EC1M 4AR, United Kingdom; Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Catherine Satzke
- Infection and Immunity, Murdoch Children's Research Institute, The University of Melbourne Department of Paediatrics at the Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia; Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Kim Mulholland
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; Infection and Immunity, Murdoch Children's Research Institute, The University of Melbourne Department of Paediatrics at the Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia
| | | | | | - Mohamed Abdi Hergeeye
- Republic of Somaliland Ministry of Health Development, 26 June District, Presidential Road, Hargeisa, Somaliland
| | - Rosalind M Eggo
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Francesco Checchi
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Stefan Flasche
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
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15
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Coleman M, Martinez L, Theron G, Wood R, Marais B. Mycobacterium tuberculosis Transmission in High-Incidence Settings-New Paradigms and Insights. Pathogens 2022; 11:1228. [PMID: 36364978 PMCID: PMC9695830 DOI: 10.3390/pathogens11111228] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 12/01/2023] Open
Abstract
Tuberculosis has affected humankind for thousands of years, but a deeper understanding of its cause and transmission only arose after Robert Koch discovered Mycobacterium tuberculosis in 1882. Valuable insight has been gained since, but the accumulation of knowledge has been frustratingly slow and incomplete for a pathogen that remains the number one infectious disease killer on the planet. Contrast that to the rapid progress that has been made in our understanding SARS-CoV-2 (the cause of COVID-19) aerobiology and transmission. In this Review, we discuss important historical and contemporary insights into M. tuberculosis transmission. Historical insights describing the principles of aerosol transmission, as well as relevant pathogen, host and environment factors are described. Furthermore, novel insights into asymptomatic and subclinical tuberculosis, and the potential role this may play in population-level transmission is discussed. Progress towards understanding the full spectrum of M. tuberculosis transmission in high-burden settings has been hampered by sub-optimal diagnostic tools, limited basic science exploration and inadequate study designs. We propose that, as a tuberculosis field, we must learn from and capitalize on the novel insights and methods that have been developed to investigate SARS-CoV-2 transmission to limit ongoing tuberculosis transmission, which sustains the global pandemic.
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Affiliation(s)
- Mikaela Coleman
- WHO Collaborating Centre for Tuberculosis and the Sydney Institute for Infectious Diseases, The University of Sydney, Sydney 2006, Australia
- Tuberculosis Research Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia
| | - Leonardo Martinez
- Department of Epidemiology, Boston University School of Public Health, Boston, MA 02118, USA
| | - Grant Theron
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7602, South Africa
| | - Robin Wood
- Desmond Tutu Health Foundation and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7700, South Africa
| | - Ben Marais
- WHO Collaborating Centre for Tuberculosis and the Sydney Institute for Infectious Diseases, The University of Sydney, Sydney 2006, Australia
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16
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Dobreva Z, Gimma A, Rohan H, Djoudalbaye B, Tshangela A, Jarvis CI, van Zandvoort K, Quaife M. Characterising social contacts under COVID-19 control measures in Africa. BMC Med 2022; 20:344. [PMID: 36221094 PMCID: PMC9553295 DOI: 10.1186/s12916-022-02543-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 08/26/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Early in the COVID-19 pandemic, countries adopted non-pharmaceutical interventions (NPIs) such as lockdowns to limit SARS-CoV-2 transmission. Social contact studies help measure the effectiveness of NPIs and estimate parameters for modelling SARS-CoV-2 transmission. However, few contact studies have been conducted in Africa. METHODS We analysed nationally representative cross-sectional survey data from 19 African Union Member States, collected by the Partnership for Evidence-based Responses to COVID-19 (PERC) via telephone interviews at two time points (August 2020 and February 2021). Adult respondents reported contacts made in the previous day by age group, demographic characteristics, and their attitudes towards COVID-19. We described mean and median contacts across these characteristics and related contacts to Google Mobility reports and the Oxford Government Response Stringency Index for each country at the two time points. RESULTS Mean reported contacts varied across countries with the lowest reported in Ethiopia (9, SD=16, median = 4, IQR = 8) in August 2020 and the highest in Sudan (50, SD=53, median = 33, IQR = 40) in February 2021. Contacts of people aged 18-55 represented 50% of total contacts, with most contacts in household and work or study settings for both surveys. Mean contacts increased for Ethiopia, Ghana, Liberia, Nigeria, Sudan, and Uganda and decreased for Cameroon, the Democratic Republic of Congo (DRC), and Tunisia between the two time points. Men had more contacts than women and contacts were consistent across urban or rural settings (except in Cameroon and Kenya, where urban respondents had more contacts than rural ones, and in Senegal and Zambia, where the opposite was the case). There were no strong and consistent variations in the number of mean or median contacts by education level, self-reported health, perceived self-reported risk of infection, vaccine acceptance, mask ownership, and perceived risk of COVID-19 to health. Mean contacts were correlated with Google mobility (coefficient 0.57, p=0.051 and coefficient 0.28, p=0.291 in August 2020 and February 2021, respectively) and Stringency Index (coefficient -0.12, p = 0.304 and coefficient -0.33, p=0.005 in August 2020 and February 2021, respectively). CONCLUSIONS These are the first COVID-19 social contact data collected for 16 of the 19 countries surveyed. We find a high reported number of daily contacts in all countries and substantial variations in mean contacts across countries and by gender. Increased stringency and decreased mobility were associated with a reduction in the number of contacts. These data may be useful to understand transmission patterns, model infection transmission, and for pandemic planning.
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Affiliation(s)
- Zlatina Dobreva
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK.
| | - Amy Gimma
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Hana Rohan
- UK Public Health Rapid Support Team, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Akhona Tshangela
- Africa Centres for Disease Control and Prevention, Addis Ababa, Ethiopia
| | - Christopher I Jarvis
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Kevin van Zandvoort
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Matthew Quaife
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
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17
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Thindwa D, Jambo KC, Ojal J, MacPherson P, Dennis Phiri M, Pinsent A, Khundi M, Chiume L, Gallagher KE, Heyderman RS, Corbett EL, French N, Flasche S. Social mixing patterns relevant to infectious diseases spread by close contact in urban Blantyre, Malawi. Epidemics 2022; 40:100590. [PMID: 35691100 PMCID: PMC9176177 DOI: 10.1016/j.epidem.2022.100590] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/08/2022] [Accepted: 05/30/2022] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION Understanding human mixing patterns relevant to infectious diseases spread through close contact is vital for modelling transmission dynamics and optimisation of disease control strategies. Mixing patterns in low-income countries like Malawi are not well known. METHODOLOGY We conducted a social mixing survey in urban Blantyre, Malawi between April and July 2021 (between the 2nd and 3rd wave of COVID-19 infections). Participants living in densely-populated neighbourhoods were randomly sampled and, if they consented, reported their physical and non-physical contacts within and outside homes lasting at least 5 min during the previous day. Age-specific mixing rates were calculated, and a negative binomial mixed effects model was used to estimate determinants of contact behaviour. RESULTS Of 1201 individuals enroled, 702 (58.5%) were female, the median age was 15 years (interquartile range [IQR] 5-32) and 127 (10.6%) were HIV-positive. On average, participants reported 10.3 contacts per day (range: 1-25). Mixing patterns were highly age-assortative, particularly those within the community and with skin-to-skin contact. Adults aged 20-49 y reported the most contacts (median:11, IQR: 8-15) of all age groups; 38% (95%CI: 16-63) more than infants (median: 8, IQR: 5-10), who had the least contacts. Household contact frequency increased by 3% (95%CI: 2-5) per additional household member. Unemployed participants had 15% (95%CI: 9-21) fewer contacts than other adults. Among long range (>30 m away from home) contacts, secondary school children had the largest median contact distance from home (257 m, IQR 78-761). HIV-positive status in adults >=18 years-old was not associated with changed contact patterns (rate ratio: 1.01, 95%CI: (0.91-1.12)). During this period of relatively low COVID-19 incidence in Malawi, 301 (25.1%) individuals stated that they had limited their contact with others due to COVID-19 precautions; however, their reported contacts were 8% (95%CI: 1-13) higher. CONCLUSION In urban Malawi, contact rates, are high and age-assortative, with little reported behavioural change due to either HIV-status or COVID-19 circulation. This highlights the limits of contact-restriction-based mitigation strategies in such settings and the need for pandemic preparedness to better understand how contact reductions can be enabled and motivated.
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Affiliation(s)
- Deus Thindwa
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK; Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi.
| | - Kondwani C Jambo
- Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - John Ojal
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK; KEMRI-Wellcome Research Programme, Geographic Medicine Centre, Kilifi, Kenya
| | - Peter MacPherson
- Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK; Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - Mphatso Dennis Phiri
- Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - McEwen Khundi
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK; Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi
| | - Lingstone Chiume
- Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi
| | - Katherine E Gallagher
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK; KEMRI-Wellcome Research Programme, Geographic Medicine Centre, Kilifi, Kenya
| | - Robert S Heyderman
- NIHR Global Health Research Unit on Mucosal Pathogens, Research Department of Infection, Division of Infection and Immunity, University College London, London, UK
| | - Elizabeth L Corbett
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - Neil French
- Malawi-Liverpool-Wellcome Clinical Research Programme, Blantyre, Malawi; Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, UK
| | - Stefan Flasche
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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18
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Dolatshahi Z, Nargesi S, Sadeghifar J, Mezginejad F, Jafari A, Bazyar M, Ghafourian S, Sani'ee N. Economic evaluation of laboratory diagnostic test types in Covid-19 epidemic: A systematic review. Int J Surg 2022; 105:106820. [PMID: 35987335 PMCID: PMC9384461 DOI: 10.1016/j.ijsu.2022.106820] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/24/2022] [Accepted: 07/30/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Corona 2 virus (SARS-CoV-2) is known as the causative agent of COVID-19 disease; the World Health Organization (WHO) declared it an epidemic on March 11, 2020. The Joint Guidelines of the Centers for Disease Control and Prevention (CDC) and the WHO including social distancing, the use of face masks, emphasis on hand washing, quarantine, and using diagnosis tests have been used widely, but the value of diagnostic interventions to prevent the transmission of SARS-CoV-2 is unclear. We compared the economic evaluation of different laboratory diagnostic interventions with each other and also with implementing the conservative CDC & WHO guidelines. MATERIAL AND METHODS Electronic searches were conducted on PubMed, Embase, Science Direct, Scopus, Cochrane Library, Web of Knowledge, NHSEED, NHS Health Technology assessment (CRD), and Cost-Effectiveness Analysis Registry databases. Related articles were reviewed from January 2020 to the end of November 2021. RESULTS Out of 1791 initial studies, 13 articles had the inclusion criteria. According to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist, ten studies were of excellent quality, and the remaining two studies were of very good quality. Most studies were cost-effectiveness analysis studies. The entered studies had different time horizons. Diagnostic tests reviewed in the studies included real-time polymerase chain reaction (RT-PCR) test, immunoglobulin G (IgG) & Antigen, point of care tests. Although polymerase chain reaction (PCR) testing improves the quality of life and survival for patients with infected Covid-19 based on its greater effectiveness compared to standard protection protocols, due to the high cost of this intervention, it has been considered a cost-effective method in some countries. CONCLUSION Since most studies have been conducted in developed countries, it unquestionably does not make sense to extend these results to low-income and developing countries. Therefore further studies are required in low-income and developing countries to evaluate the cost-effectiveness of laboratory-based diagnostic methods (RT-PCR) of covid-19 in variable prevalence of infectious cases.
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Affiliation(s)
- Zeinab Dolatshahi
- Department of Health Policy, School of Health Management and Information Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Shahin Nargesi
- Department of Health Management and Economics, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran.
| | - Jamil Sadeghifar
- Department of Health Management and Economics, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran
| | - Fateme Mezginejad
- Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Abdosaleh Jafari
- Health Human Resources Research Center, School of Health Management and Information Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Bazyar
- Department of Health Management and Economics, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran
| | - Sobhan Ghafourian
- Department of Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Nadia Sani'ee
- Ph.D. in Medical Library and Information Science, Spiritual Health Research Center, Iran University of Medical Sciences, Tehran, Iran
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19
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Ma L, Shapira G, de Walque D, Do Q, Friedman J, Levchenko AA. THE INTERGENERATIONAL MORTALITY TRADE-OFF OF COVID-19 LOCKDOWN POLICIES. INTERNATIONAL ECONOMIC REVIEW 2022; 63:IERE12574. [PMID: 35600320 PMCID: PMC9111371 DOI: 10.1111/iere.12574] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 01/28/2022] [Indexed: 05/21/2023]
Abstract
In lower-income countries, the economic contractions that accompany lockdowns to contain COVID-19 transmission can increase child mortality, counteracting the mortality reductions achieved by the lockdown. To formalize and quantify this effect, we build a macrosusceptible-infected-recovered model that features heterogeneous agents and a country-group-specific relationship between economic downturns and child mortality and calibrate it to data for 85 countries across all income levels. We find that in some low-income countries, a lockdown can produce net increases in mortality. The optimal lockdown that maximizes the present value of aggregate social welfare is shorter and milder in poorer countries than in rich ones.
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Affiliation(s)
- Lin Ma
- Singapore Management UniversitySingapore
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20
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Thomas MM, Mohammadi N, Taylor JE. Investigating the association between mass transit adoption and COVID-19 infections in US metropolitan areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:152284. [PMID: 34902421 PMCID: PMC8662904 DOI: 10.1016/j.scitotenv.2021.152284] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 05/26/2023]
Abstract
Urbanization introduces the threat of increased epidemic disease transmission resulting from crowding on mass transit. The coronavirus disease 2019 (COVID-19) pandemic, which has directly led to over 600,000 deaths in the US as of July 2021, triggered mass social distancing policies to be enacted as a key deterrent of widespread infections. Social distancing can be challenging in confined spaces required for transportation such as mass transit systems. Little is published regarding the degree to which mass transit system adoption effects impacted the rise of the COVID-19 pandemic in urban centers. Taking an ecological approach where areal data are the unit of observation, this national-scale study aims to measure the association between the adoption of mass transit and COVID-19 spread through confirmed cases in US metropolitan areas. National survey-based transit adoption measures are entered in negative binomial regression models to evaluate differences between areas. The model results demonstrate that mass transit adoption in US metropolitan areas was associated with the magnitude of outbreaks. Higher incidence of COVID-19 early in the pandemic was associated with survey results conveying higher transit use. Increasing weekly bus transit usage in metropolitan statistical areas by one scaled unit was associated with a 1.38 [95% CI: (1.25, 1.90)] times increase in incidence rate of COVID-19; a one scaled unit increase in weekly train transit usage was associated with an increase in incidence rate of 1.54 [95% CI: (1.42, 2.07)] times. These conclusions should inform early action practices in urban centers with busy transit systems in the event of future infectious disease outbreaks. Deeper understanding of these observed associations may also benefit modeling efforts by allowing researchers to include mathematical adjustments or better explain caveats to results when communicating with decision makers and the public in the crucial early stages of an epidemic.
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Affiliation(s)
- Michael M Thomas
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr NW, Atlanta, GA 30332, United States.
| | - Neda Mohammadi
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr NW, Atlanta, GA 30332, United States.
| | - John E Taylor
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr NW, Atlanta, GA 30332, United States.
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21
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Potter GE, Carnegie NB, Sugimoto JD, Diallo A, Victor JC, Neuzil KM, Halloran ME. Using social contact data to improve the overall effect estimate of a cluster-randomized influenza vaccination program in Senegal. J R Stat Soc Ser C Appl Stat 2022; 71:70-90. [PMID: 35721226 PMCID: PMC9202735 DOI: 10.1111/rssc.12522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study estimates the overall effect of two influenza vaccination programs consecutively administered in a cluster-randomized trial in western Senegal over the course of two influenza seasons from 2009-2011. We apply cutting-edge methodology combining social contact data with infection data to reduce bias in estimation arising from contamination between clusters. Our time-varying estimates reveal a reduction in seasonal influenza from the intervention and a nonsignificant increase in H1N1 pandemic influenza. We estimate an additive change in overall cumulative incidence (which was 6.13% in the control arm) of -0.68 percentage points during Year 1 of the study (95% CI: -2.53, 1.18). When H1N1 pandemic infections were excluded from analysis, the estimated change was -1.45 percentage points and was significant (95% CI, -2.81, -0.08). Because cross-cluster contamination was low (0-3% of contacts for most villages), an estimator assuming no contamination was only slightly attenuated (-0.65 percentage points). These findings are encouraging for studies carefully designed to minimize spillover. Further work is needed to estimate contamination - and its effect on estimation - in a variety of settings.
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Affiliation(s)
- Gail E Potter
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, and the Emmes Company, Rockville Maryland, USA
| | | | - Jonathan D Sugimoto
- University of Washington and Epidemiologic Research and Information Center, Veterans Affairs Puget Sound Health Care System and Fred Hutchinson Cancer Research Center, Seattle Washington, USA
| | - Aldiouma Diallo
- Institut de Recherche pour le Développement, Niakhar Senegal
| | | | | | - M Elizabeth Halloran
- University of Washington Department of Biostatistics and Fred Hutchinson Cancer Research Center, Seattle Washington, USA
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22
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Fennelly KP, Martinez L, Mandalakas AM. Tuberculosis: First in Flight. Am J Respir Crit Care Med 2021; 205:272-274. [PMID: 34905703 PMCID: PMC8886999 DOI: 10.1164/rccm.202111-2513ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Kevin P Fennelly
- National Institutes of Health, Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States;
| | - Leonardo Martinez
- Boston University, 1846, Department of Epidemiology, School of Public Health, Boston, Massachusetts, United States
| | - Anna Maria Mandalakas
- Baylor College of Medicine and Texas Children's Hospital, Global TB Program, Department of Pediatrics, Houston, Texas, United States
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23
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Polonsky JA, Böhning D, Keita M, Ahuka-Mundeke S, Nsio-Mbeta J, Abedi AA, Mossoko M, Estill J, Keiser O, Kaiser L, Yoti Z, Sangnawakij P, Lerdsuwansri R, Vilas VJDR. Novel Use of Capture-Recapture Methods to Estimate Completeness of Contact Tracing during an Ebola Outbreak, Democratic Republic of the Congo, 2018-2020. Emerg Infect Dis 2021; 27:3063-3072. [PMID: 34808076 PMCID: PMC8632194 DOI: 10.3201/eid2712.204958] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Despite its critical role in containing outbreaks, the efficacy of contact tracing, measured as the sensitivity of case detection, remains an elusive metric. We estimated the sensitivity of contact tracing by applying unilist capture-recapture methods on data from the 2018–2020 outbreak of Ebola virus disease in the Democratic Republic of the Congo. To compute sensitivity, we applied different distributional assumptions to the zero-truncated count data to estimate the number of unobserved case-patients with any contacts and infected contacts. Geometric distributions were the best-fitting models. Our results indicate that contact tracing efforts identified almost all (n = 792, 99%) of case-patients with any contacts but only half (n = 207, 48%) of case-patients with infected contacts, suggesting that contact tracing efforts performed well at identifying contacts during the listing stage but performed poorly during the contact follow-up stage. We discuss extensions to our work and potential applications for the ongoing coronavirus pandemic.
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24
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Del Fava E, Adema I, Kiti MC, Poletti P, Merler S, Nokes DJ, Manfredi P, Melegaro A. Individual's daily behaviour and intergenerational mixing in different social contexts of Kenya. Sci Rep 2021; 11:21589. [PMID: 34732732 PMCID: PMC8566563 DOI: 10.1038/s41598-021-00799-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 10/15/2021] [Indexed: 12/20/2022] Open
Abstract
We investigated contact patterns in diverse social contexts in Kenya and the daily behaviours that may play a pivotal role in infection transmission to the most vulnerable leveraging novel data from a 2-day survey on social contacts and time use (TU) from a sample of 1407 individuals (for a total of 2705 person days) from rural, urban formal, and informal settings. We used TU data to build six profiles of daily behaviour based on the main reported activities, i.e., Homestayers (71.1% of person days), Workers (9.3%), Schoolers (7.8%), or locations at increasing distance from home, i.e., Walkers (6.6%), Commuters (4.6%), Travelers (0.6%). In the rural setting, we observed higher daily contact numbers (11.56, SD 0.23) and percentages of intergenerational mixing with older adults (7.5% of contacts reported by those younger than 60 years vs. less than 4% in the urban settings). Overall, intergenerational mixing with older adults was higher for Walkers (7.3% of their reported contacts), Commuters (8.7%), and Homestayers (5.1%) than for Workers (1.5%) or Schoolers (3.6%). These results could be instrumental in defining effective interventions that acknowledge the heterogeneity in social contexts and daily routines, either in Kenya or other demographically and culturally similar sub-Saharan African settings.
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Affiliation(s)
- Emanuele Del Fava
- Carlo F. Dondena Centre for Research on Social Dynamics and Public Policy, Bocconi University, Milan, Italy
- Max Planck Institute for Demographic Research, Rostock, Germany
| | - Irene Adema
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Moses C Kiti
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - D James Nokes
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- School of Life Sciences and Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research (SBIDER), University of Warwick, Coventry, UK
| | | | - Alessia Melegaro
- Carlo F. Dondena Centre for Research on Social Dynamics and Public Policy, Bocconi University, Milan, Italy.
- Department of Social and Political Sciences, Bocconi University, Milan, Italy.
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25
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McCreesh N, Dlamini V, Edwards A, Olivier S, Dayi N, Dikgale K, Nxumalo S, Dreyer J, Baisley K, Siedner MJ, White RG, Herbst K, Grant AD, Harling G. Impact of the Covid-19 epidemic and related social distancing regulations on social contact and SARS-CoV-2 transmission potential in rural South Africa: analysis of repeated cross-sectional surveys. BMC Infect Dis 2021; 21:928. [PMID: 34496771 PMCID: PMC8424154 DOI: 10.1186/s12879-021-06604-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 08/23/2021] [Indexed: 12/11/2022] Open
Abstract
Background South Africa implemented rapid and strict physical distancing regulations to minimize SARS-CoV-2 epidemic spread. Evidence on the impact of such measures on interpersonal contact in rural and lower-income settings is limited. Methods We compared population-representative social contact surveys conducted in the same rural KwaZulu-Natal location once in 2019 and twice in mid-2020. Respondents reported characteristics of physical and conversational (‘close interaction’) contacts over 24 hours. We built age-mixing matrices and estimated the proportional change in the SARS-CoV-2 reproduction number (R0). Respondents also reported counts of others present at locations visited and transport used, from which we evaluated change in potential exposure to airborne infection due to shared indoor space (‘shared air’). Results Respondents in March–December 2019 (n = 1704) reported a mean of 7.4 close interaction contacts and 196 shared air person-hours beyond their homes. Respondents in June-July 2020 (n = 216), as the epidemic peaked locally, reported 4.1 close interaction contacts and 21 shared air person-hours outside their home, with significant declines in others’ homes and public spaces. Adults aged over 50 had fewer close contacts with others over 50, but little change in contact with 15–29 year olds, reflecting ongoing contact within multigenerational households. We estimate potential R0 fell by 42% (95% plausible range 14–59%) between 2019 and June-July 2020. Conclusions Extra-household social contact fell substantially following imposition of Covid-19 distancing regulations in rural South Africa. Ongoing contact within intergenerational households highlighted a potential limitation of social distancing measures in protecting older adults. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-021-06604-8.
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Affiliation(s)
- Nicky McCreesh
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Vuyiswa Dlamini
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Anita Edwards
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Stephen Olivier
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Njabulo Dayi
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Keabetswe Dikgale
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Siyabonga Nxumalo
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Jaco Dreyer
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Kathy Baisley
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa
| | - Mark J Siedner
- Harvard Medical School and the Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Richard G White
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Kobus Herbst
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa.,DSI-MRC South African Population Research Infrastructure Network, Durban, South Africa
| | - Alison D Grant
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa.,TB Centre, London School of Hygiene and Tropical Medicine, London, UK.,School of Laboratory and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, KwaZulu-Natal, Durban, South Africa.,School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Guy Harling
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa. .,Institute for Global Health, University College London, London, UK. .,Department of Epidemiology & Harvard Center for Population and Development Studies, Harvard T.H. Chan School of Public Health, Boston, MA, USA. .,MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.
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Davies-Barrett AM, Owens LS, Eeckhout PA. Paleopathology of the Ychsma: Evidence of respiratory disease during the Late Intermediate Period (AD 1000-1476) at the Central Coastal site of Pachacamac, Peru. INTERNATIONAL JOURNAL OF PALEOPATHOLOGY 2021; 34:63-75. [PMID: 34153817 DOI: 10.1016/j.ijpp.2021.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVE To investigate evidence for maxillary sinusitis and pulmonary inflammation in archaeological skeletons dating to the Late Intermediate Period (AD 1000-1476) at the site of Pachacamac, Peru. MATERIALS Thirty-nine individuals (male, female, and unknown sex; 16+ years age-at-death) were analyzed for inflammatory periosteal reaction (IPR) on the visceral (inner) surfaces of the ribs, and 16 individuals were analyzed for evidence of maxillary sinusitis. METHODS All individuals were macroscopically examined for bony changes in the maxillary sinuses and new bone formation on the ribs according to pre-established criteria. RESULTS Some 33.3% (13/39) of individuals had IPR on the ribs and 93.8% (15/16) had bony changes in the maxillary sinuses. CONCLUSIONS Respiratory disease was likely prevalent in people buried at Pachacamac during the Late Intermediate Period. A number of factors may have increased the risk of developing respiratory disease, including exposure to poor air quality and increased crowding and social mixing, resulting from pilgrimage to this important ritual center. SIGNIFICANCE This paper represents one of the first systematic analyses of evidence for respiratory disease in Peruvian and South American human skeletal remains, demonstrating the suitability of the region for further study. LIMITATIONS A limited sample was available for analysis. Additionally, the site's skeletal preservation was excellent, meaning the sample available for assessment of maxillary sinusitis was smaller, being limited to individuals with post-mortem breakage. FURTHER RESEARCH The results of this study should stimulate further much needed systematic investigation of evidence for respiratory disease in other Peruvian and South American populations.
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Affiliation(s)
- Anna M Davies-Barrett
- School of History, Archaeology and Religion, Cardiff University, John Percival Building, Colum Drive, Cardiff, CF10 3EU, United Kingdom.
| | - Lawrence S Owens
- University of Winchester. Sparkford Road, Winchester, SO22 4NR, United Kingdom; University of South Africa, Preller Street, Muckleneuk, Pretoria, 0002, South Africa
| | - Peter A Eeckhout
- Faculté de Philosophie et Sciences Sociales CP133/01, Université libre de Bruxelles, Av. F. Roosevelt 50, 1050, Brussels, Belgium
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Prem K, Zandvoort KV, Klepac P, Eggo RM, Davies NG, Cook AR, Jit M. Projecting contact matrices in 177 geographical regions: An update and comparison with empirical data for the COVID-19 era. PLoS Comput Biol 2021. [PMID: 34310590 DOI: 10.1101/2020.07.22.20159772] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
Mathematical models have played a key role in understanding the spread of directly-transmissible infectious diseases such as Coronavirus Disease 2019 (COVID-19), as well as the effectiveness of public health responses. As the risk of contracting directly-transmitted infections depends on who interacts with whom, mathematical models often use contact matrices to characterise the spread of infectious pathogens. These contact matrices are usually generated from diary-based contact surveys. However, the majority of places in the world do not have representative empirical contact studies, so synthetic contact matrices have been constructed using more widely available setting-specific survey data on household, school, classroom, and workplace composition combined with empirical data on contact patterns in Europe. In 2017, the largest set of synthetic contact matrices to date were published for 152 geographical locations. In this study, we update these matrices with the most recent data and extend our analysis to 177 geographical locations. Due to the observed geographic differences within countries, we also quantify contact patterns in rural and urban settings where data is available. Further, we compare both the 2017 and 2020 synthetic matrices to out-of-sample empirically-constructed contact matrices, and explore the effects of using both the empirical and synthetic contact matrices when modelling physical distancing interventions for the COVID-19 pandemic. We found that the synthetic contact matrices show qualitative similarities to the contact patterns in the empirically-constructed contact matrices. Models parameterised with the empirical and synthetic matrices generated similar findings with few differences observed in age groups where the empirical matrices have missing or aggregated age groups. This finding means that synthetic contact matrices may be used in modelling outbreaks in settings for which empirical studies have yet to be conducted.
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Affiliation(s)
- Kiesha Prem
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Kevin van Zandvoort
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Petra Klepac
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rosalind M Eggo
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Nicholas G Davies
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Prem K, van Zandvoort K, Klepac P, Eggo RM, Davies NG, Cook AR, Jit M. Projecting contact matrices in 177 geographical regions: An update and comparison with empirical data for the COVID-19 era. PLoS Comput Biol 2021; 17:e1009098. [PMID: 34310590 PMCID: PMC8354454 DOI: 10.1371/journal.pcbi.1009098] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/10/2021] [Accepted: 05/20/2021] [Indexed: 01/08/2023] Open
Abstract
Mathematical models have played a key role in understanding the spread of directly-transmissible infectious diseases such as Coronavirus Disease 2019 (COVID-19), as well as the effectiveness of public health responses. As the risk of contracting directly-transmitted infections depends on who interacts with whom, mathematical models often use contact matrices to characterise the spread of infectious pathogens. These contact matrices are usually generated from diary-based contact surveys. However, the majority of places in the world do not have representative empirical contact studies, so synthetic contact matrices have been constructed using more widely available setting-specific survey data on household, school, classroom, and workplace composition combined with empirical data on contact patterns in Europe. In 2017, the largest set of synthetic contact matrices to date were published for 152 geographical locations. In this study, we update these matrices with the most recent data and extend our analysis to 177 geographical locations. Due to the observed geographic differences within countries, we also quantify contact patterns in rural and urban settings where data is available. Further, we compare both the 2017 and 2020 synthetic matrices to out-of-sample empirically-constructed contact matrices, and explore the effects of using both the empirical and synthetic contact matrices when modelling physical distancing interventions for the COVID-19 pandemic. We found that the synthetic contact matrices show qualitative similarities to the contact patterns in the empirically-constructed contact matrices. Models parameterised with the empirical and synthetic matrices generated similar findings with few differences observed in age groups where the empirical matrices have missing or aggregated age groups. This finding means that synthetic contact matrices may be used in modelling outbreaks in settings for which empirical studies have yet to be conducted.
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Affiliation(s)
- Kiesha Prem
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Kevin van Zandvoort
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Petra Klepac
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rosalind M. Eggo
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Nicholas G. Davies
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Alex R. Cook
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Prem K, Zandvoort KV, Klepac P, Eggo RM, Davies NG, Cook AR, Jit M. Projecting contact matrices in 177 geographical regions: An update and comparison with empirical data for the COVID-19 era. PLoS Comput Biol 2021; 17:e1009098. [PMID: 34310590 DOI: 10.5281/zenodo.4889500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/10/2021] [Accepted: 05/20/2021] [Indexed: 05/20/2023] Open
Abstract
Mathematical models have played a key role in understanding the spread of directly-transmissible infectious diseases such as Coronavirus Disease 2019 (COVID-19), as well as the effectiveness of public health responses. As the risk of contracting directly-transmitted infections depends on who interacts with whom, mathematical models often use contact matrices to characterise the spread of infectious pathogens. These contact matrices are usually generated from diary-based contact surveys. However, the majority of places in the world do not have representative empirical contact studies, so synthetic contact matrices have been constructed using more widely available setting-specific survey data on household, school, classroom, and workplace composition combined with empirical data on contact patterns in Europe. In 2017, the largest set of synthetic contact matrices to date were published for 152 geographical locations. In this study, we update these matrices with the most recent data and extend our analysis to 177 geographical locations. Due to the observed geographic differences within countries, we also quantify contact patterns in rural and urban settings where data is available. Further, we compare both the 2017 and 2020 synthetic matrices to out-of-sample empirically-constructed contact matrices, and explore the effects of using both the empirical and synthetic contact matrices when modelling physical distancing interventions for the COVID-19 pandemic. We found that the synthetic contact matrices show qualitative similarities to the contact patterns in the empirically-constructed contact matrices. Models parameterised with the empirical and synthetic matrices generated similar findings with few differences observed in age groups where the empirical matrices have missing or aggregated age groups. This finding means that synthetic contact matrices may be used in modelling outbreaks in settings for which empirical studies have yet to be conducted.
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Affiliation(s)
- Kiesha Prem
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Kevin van Zandvoort
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Petra Klepac
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rosalind M Eggo
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Nicholas G Davies
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Horton KC, Hoey AL, Béraud G, Corbett EL, White RG. Systematic Review and Meta-Analysis of Sex Differences in Social Contact Patterns and Implications for Tuberculosis Transmission and Control. Emerg Infect Dis 2021; 26:910-919. [PMID: 32310063 PMCID: PMC7181919 DOI: 10.3201/eid2605.190574] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Social contact patterns might contribute to excess burden of tuberculosis in men. We conducted a study of social contact surveys to evaluate contact patterns relevant to tuberculosis transmission. Available data describe 21 surveys in 17 countries and show profound differences in sex-based and age-based patterns of contact. Adults reported more adult contacts than children. Children preferentially mixed with women in all surveys (median sex assortativity 58%, interquartile range [IQR] 57%–59% for boys, 61% [IQR 60%–63%] for girls). Men and women reported sex-assortative mixing in 80% and 95% of surveys (median sex assortativity 56% [IQR 54%–58%] for men, 59% [IQR 57%–63%] for women). Sex-specific patterns of contact with adults were similar at home and outside the home for children; adults reported greater sex assortativity outside the home in most surveys. Sex assortativity in adult contacts likely contributes to sex disparities in adult tuberculosis burden by amplifying incidence among men.
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Kleynhans J, Tempia S, McMorrow ML, von Gottberg A, Martinson NA, Kahn K, Moyes J, Mkhencele T, Lebina L, Gómez-Olivé FX, Wafawanaka F, Mathunjwa A, Cohen C. A cross-sectional study measuring contact patterns using diaries in an urban and a rural community in South Africa, 2018. BMC Public Health 2021; 21:1055. [PMID: 34078327 PMCID: PMC8172361 DOI: 10.1186/s12889-021-11136-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/24/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Describing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates. METHODS We conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations. RESULTS We conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9-33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10-23) compared to the urban site, for those aged 14-18 years (13, 95%CI 3-23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14-18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban). CONCLUSIONS Age played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.
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Affiliation(s)
- Jackie Kleynhans
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Stefano Tempia
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa
- MassGenics, Duluth, Georgia, USA
| | - Meredith L McMorrow
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa
- United States Public Health Service, Rockville, MD, USA
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Neil A Martinson
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
- Johns Hopkins University Center for Tuberculosis Research, Baltimore, MD, USA
- Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, University of the Witwatersrand, Johannesburg, South Africa
| | - Kathleen Kahn
- MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jocelyn Moyes
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Thulisa Mkhencele
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Limakatso Lebina
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - F Xavier Gómez-Olivé
- MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Floidy Wafawanaka
- MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Azwifarwi Mathunjwa
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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McQuaid CF, Vassall A, Cohen T, Fiekert K, White RG. The impact of COVID-19 on TB: a review of the data. Int J Tuberc Lung Dis 2021; 25:436-446. [PMID: 34049605 PMCID: PMC8171247 DOI: 10.5588/ijtld.21.0148] [Citation(s) in RCA: 150] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022] Open
Abstract
Early in the COVID-19 pandemic, models predicted hundreds of thousands of additional TB deaths as a result of health service disruption. To date, empirical evidence on the effects of COVID-19 on TB outcomes has been limited. Here we summarise the evidence available at a country level, identifying broad mechanisms by which COVID-19 may modify TB burden and mitigation efforts. From the data, it is clear that there have been substantial disruptions to TB health services and an increase in vulnerability to TB. Evidence for changes in Mycobacterium tuberculosis transmission is limited, and it remains unclear how the resources required and available for the TB response have changed. To advocate for additional funding to mitigate the impact of COVID-19 on the global TB burden, and to efficiently allocate resources for the TB response, requires a significant improvement in the TB data available.
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Affiliation(s)
- C F McQuaid
- TB Modelling Group, TB Centre and Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine (LSHTM), London, UK
| | - A Vassall
- Department of Global Health Development, Faculty of Public Health and Policy, LSHTM, London, UK
| | - T Cohen
- Yale School of Public Health, Laboratory of Epidemiology and Public Health, New Haven, CT, USA
| | - K Fiekert
- KNCV Tuberculosefonds, The Hague, the Netherlands
| | - R G White
- TB Modelling Group, TB Centre and Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine (LSHTM), London, UK
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Sewpaul R, Mabaso M, Dukhi N, Naidoo I, Vondo N, Davids AS, Mokhele T, Reddy SP. Determinants of Social Distancing Among South Africans From 12 Days Into the COVID-19 Lockdown: A Cross Sectional Study. Front Public Health 2021; 9:632619. [PMID: 34109143 PMCID: PMC8180596 DOI: 10.3389/fpubh.2021.632619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/12/2021] [Indexed: 12/23/2022] Open
Abstract
Introduction: Social or physical distancing has been an effective measure for reducing the spread of COVID-19 infections. Investigating the determinants of adherence to social distancing can inform public health strategies to improve the behaviour. However, there is a lack of data in various populations. This study investigates the degree to which South Africans complied with social distancing during the country's COVID-19 lockdown and identifies the determinants associated with being in close contact with large numbers of people. Materials and Methods: Data was collected from a South African national online survey on a data free platform, supplemented with telephone interviews. The survey was conducted from 8 to 29 April 2020. The primary outcome was the number of people that participants came into close contact with (within a 2-metre distance) the last time they were outside their home during the COVID-19 lockdown. Multivariate multinomial regression investigated the socio-demographic, psychosocial and household environmental determinants associated with being in contact with 1-10, 11-50 and more than 50 people. Results: Of the 17,563 adult participants, 20.3% reported having not left home, 50.6% were in close physical distance with 1-10 people, 21.1% with 11-50 people, and 8.0% with >50 people. Larger household size and incorrect knowledge about the importance of social distancing were associated with being in contact with >50 people. Male gender, younger age and being in the White and Coloured population groups were significantly associated with being in contact with 1-10 people but not with larger numbers of people. Employment, at least secondary school education, lack of self-efficacy in being able to protect oneself from infection, and moderate or high risk perception of becoming infected, were all associated with increased odds of close contact with 1-10, 11-50, and >50 people relative to remaining at home. Conclusion: The findings identify subgroups of individuals that are less likely to comply with social distancing regulations. Public health communication, interventions and policy can be tailored to address these determinants of social distancing.
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Affiliation(s)
- Ronel Sewpaul
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
| | - Musawenkosi Mabaso
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
| | - Natisha Dukhi
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
| | - Inbarani Naidoo
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
| | - Noloyiso Vondo
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
| | - Adlai Steven Davids
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
- Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa
| | - Tholang Mokhele
- eResearch Knowledge Centre, Human Sciences Research Council, Pretoria, South Africa
| | - Sasiragha Priscilla Reddy
- Human and Social Capabilities Division, Human Sciences Research Council, Pretoria, South Africa
- Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa
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Pinchoff J, Kraus-Perrotta C, Austrian K, Tidwell JB, Abuya T, Mwanga D, Kangwana B, Ochako R, Muluve E, Mbushi F, Nzioki M, Ngo TD. Mobility Patterns During COVID-19 Travel Restrictions in Nairobi Urban Informal Settlements: Who Is Leaving Home and Why. J Urban Health 2021; 98:211-221. [PMID: 33533010 PMCID: PMC7852483 DOI: 10.1007/s11524-020-00507-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/15/2020] [Indexed: 11/22/2022]
Abstract
Nairobi's urban slums are ill equipped to prevent spread of the novel coronavirus disease (COVID-19) due to high population density, multigenerational families in poorly ventilated informal housing, and poor sanitation. Physical distancing policies, curfews, and a citywide lockdown were implemented in March and April 2020 resulting in sharp decreases in movement across the city. However, most people cannot afford to stay home completely (e.g., leaving daily to fetch water). If still employed, they may need to travel longer distances for work, potentially exposing them COVID-19 or contributing to its spread. We conducted a household survey across five urban slums to describe factors associated with mobility in the previous 24 h. A total of 1695 adults were interviewed, 63% female. Of these, most reported neighborhood mobility within their informal settlement (54%), 19% stayed home completely, and 27% reported long-distance mobility outside their informal settlement, mainly for work. In adjusted multinomial regression models, women were 58% more likely than men to stay home (relative risk ratio (RRR): 1.58, 95% confidence interval (CI): 1.16, 2.14) and women were 60% less likely than men to report citywide mobility (RRR: 0.40; 95% CI 0.31, 0.52). Individuals in the wealthiest quintile, particularly younger women, were most likely to not leave home at all. Those who reported citywide travel were less likely to have lost employment (RRR: 0.49; 95% CI 0.38, 0.65) and were less likely to avoid public transportation (RRR: 0.30; 95% CI 0.23, 0.39). Employment and job hunting were the main reasons for traveling outside of the slum; less than 20% report other reasons. Our findings suggest that slum residents who retain their employment are traveling larger distances across Nairobi, using public transportation, and are more likely to be male; this travel may put them at higher risk of COVID-19 infection but is necessary to maintain income. Steps to protect workers from COVID-19 both in the workplace and while in transit (including masks, hand sanitizer stations, and reduced capacity on public transportation) are critical as economic insecurity in the city increases due to COVID-19 mitigation measures. Workers must be able to commute and maintain employment to not be driven further into poverty. Additionally, to protect the majority of individuals who are only travelling locally within their settlement, mitigation measures such as making masks and handwashing stations accessible within informal settlements must also be implemented, with special attention to the burden placed on women.
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Hoang TV, Coletti P, Kifle YW, Kerckhove KV, Vercruysse S, Willem L, Beutels P, Hens N. Close contact infection dynamics over time: insights from a second large-scale social contact survey in Flanders, Belgium, in 2010-2011. BMC Infect Dis 2021; 21:274. [PMID: 33736606 PMCID: PMC7971398 DOI: 10.1186/s12879-021-05949-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/02/2021] [Indexed: 01/10/2023] Open
Abstract
Background In 2010-2011, we conducted a social contact survey in Flanders, Belgium, aimed at improving and extending the design of the first social contact survey conducted in Belgium in 2006. This second social contact survey aimed to enable, for the first time, the estimation of social mixing patterns for an age range of 0 to 99 years and the investigation of whether contact rates remain stable over this 5-year time period. Methods Different data mining techniques are used to explore the data, and the age-specific number of social contacts and the age-specific contact rates are modelled using a generalized additive models for location, scale and shape (GAMLSS) model. We compare different matrices using assortativeness measures. The relative change in the basic reproduction number (R0) and the ratio of relative incidences with 95% bootstrap confidence intervals (BCI) are employed to investigate and quantify the impact on epidemic spread due to differences in sex, day of the week, holiday vs. regular periods and changes in mixing patterns over the 5-year time gap between the 2006 and 2010-2011 surveys. Finally, we compare the fit of the contact matrices in 2006 and 2010-2011 to Varicella serological data. Results All estimated contact patterns featured strong homophily in age and sex, especially for small children and adolescents. A 30% (95% BCI [17%; 37%]) and 29% (95% BCI [14%; 40%]) reduction in R0 was observed for weekend versus weekdays and for holiday versus regular periods, respectively. Significantly more interactions between people aged 60+ years and their grandchildren were observed on holiday and weekend days than on regular weekdays. Comparing contact patterns using different methods did not show any substantial differences over the 5-year time period under study. Conclusions The second social contact survey in Flanders, Belgium, endorses the findings of its 2006 predecessor and adds important information on the social mixing patterns of people older than 60 years of age. Based on this analysis, the mixing patterns of people older than 60 years exhibit considerable heterogeneity, and overall, the comparison of the two surveys shows that social contact rates can be assumed stable in Flanders over a time span of 5 years. Supplementary Information The online version contains supplementary material available at (10.1186/s12879-021-05949-4).
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Affiliation(s)
- Thang Van Hoang
- I-Biostat, Data Science Institute, Hasselt University, Martelarenlaan 42, Hasselt, 3500, Belgium.
| | - Pietro Coletti
- I-Biostat, Data Science Institute, Hasselt University, Martelarenlaan 42, Hasselt, 3500, Belgium
| | - Yimer Wasihun Kifle
- The Janssen Pharmaceutical Companies of Johnson & Johnson, Antwerpen, Belgium
| | - Kim Van Kerckhove
- I-Biostat, Data Science Institute, Hasselt University, Martelarenlaan 42, Hasselt, 3500, Belgium
| | - Sarah Vercruysse
- I-Biostat, Data Science Institute, Hasselt University, Martelarenlaan 42, Hasselt, 3500, Belgium
| | - Lander Willem
- Centre for Health Economic Research and Modelling Infectious Diseases, Vaccine & Infectious Diseases Institute, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Philippe Beutels
- Centre for Health Economic Research and Modelling Infectious Diseases, Vaccine & Infectious Diseases Institute, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium.,School of Public health and Community Medicine, University of New South Wales, Sydney, 2052, Australia
| | - Niel Hens
- I-Biostat, Data Science Institute, Hasselt University, Martelarenlaan 42, Hasselt, 3500, Belgium.,Centre for Health Economic Research and Modelling Infectious Diseases, Vaccine & Infectious Diseases Institute, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
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Transmission Modeling with Regression Adjustment for Analyzing Household-based Studies of Infectious Disease: Application to Tuberculosis. Epidemiology 2021; 31:238-247. [PMID: 31764276 DOI: 10.1097/ede.0000000000001143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Household contacts of people infected with a transmissible disease may be at risk due to this proximate exposure, or from other unobserved sources. Understanding variation in infection risk is essential for targeting interventions. METHODS We develop an analytical approach to estimate household and exogenous forces of infection, while accounting for individual-level characteristics that affect susceptibility to disease and transmissibility. We apply this approach to a cohort study conducted in Lima, Peru, of 18,544 subjects in 4,500 households with at least one active tuberculosis (TB) case and compare the results to those obtained by Poisson and logistic regression. RESULTS HIV-coinfected (susceptibility hazard ratio [SHR] = 3.80, 1.56-9.29), child (SHR = 1.72, 1.32-2.23), and teenage (SHR = 2.00, 1.49-2.68) household contacts of TB cases experience a higher hazard of TB than do adult contacts. Isoniazid preventive therapy (SHR = 0.30, 0.21-0.42) and Bacillus Calmette-Guérin (BCG) vaccination (SHR = 0.66, 0.51-0.86) reduce the risk of disease among household contacts. TB cases without microbiological confirmation exert a smaller hazard of TB among their close contacts compared with smear- or culture-positive cases (excess hazard ratio = 0.88, 0.82-0.93 for HIV- cases and 0.82, 0.57-0.94 for HIV+ cases). The extra household force of infection results in 0.01 (95% confidence interval [CI] = 0.004, 0.028) TB cases per susceptible household contact per year and the rate of transmission between a microbiologically confirmed TB case and susceptible household contact at 0.08 (95% CI = 0.045, 0.129) TB cases per pair per year. CONCLUSIONS Accounting for exposure to infected household contacts permits estimation of risk factors for disease susceptibility and transmissibility and comparison of within-household and exogenous forces of infection.
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Hu S, Wang W, Wang Y, Litvinova M, Luo K, Ren L, Sun Q, Chen X, Zeng G, Li J, Liang L, Deng Z, Zheng W, Li M, Yang H, Guo J, Wang K, Chen X, Liu Z, Yan H, Shi H, Chen Z, Zhou Y, Sun K, Vespignani A, Viboud C, Gao L, Ajelli M, Yu H. Infectivity, susceptibility, and risk factors associated with SARS-CoV-2 transmission under intensive contact tracing in Hunan, China. Nat Commun 2021; 12:1533. [PMID: 33750783 PMCID: PMC7943579 DOI: 10.1038/s41467-021-21710-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/02/2021] [Indexed: 01/08/2023] Open
Abstract
Several mechanisms driving SARS-CoV-2 transmission remain unclear. Based on individual records of 1178 potential SARS-CoV-2 infectors and their 15,648 contacts in Hunan, China, we estimated key transmission parameters. The mean generation time was estimated to be 5.7 (median: 5.5, IQR: 4.5, 6.8) days, with infectiousness peaking 1.8 days before symptom onset, with 95% of transmission events occurring between 8.8 days before and 9.5 days after symptom onset. Most transmission events occurred during the pre-symptomatic phase (59.2%). SARS-CoV-2 susceptibility to infection increases with age, while transmissibility is not significantly different between age groups and between symptomatic and asymptomatic individuals. Contacts in households and exposure to first-generation cases are associated with higher odds of transmission. Our findings support the hypothesis that children can effectively transmit SARS-CoV-2 and highlight how pre-symptomatic and asymptomatic transmission can hinder control efforts.
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Affiliation(s)
- Shixiong Hu
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Wei Wang
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Yan Wang
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Maria Litvinova
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health, Bloomington, IN, USA
- ISI Foundation, Turin, Italy
| | - Kaiwei Luo
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Lingshuang Ren
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Qianlai Sun
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Xinghui Chen
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Ge Zeng
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Jing Li
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Lu Liang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhihong Deng
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Wen Zheng
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Mei Li
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Hao Yang
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Jinxin Guo
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Kai Wang
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Xinhua Chen
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Ziyan Liu
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Han Yan
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Huilin Shi
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Zhiyuan Chen
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Yonghong Zhou
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Kaiyuan Sun
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Alessandro Vespignani
- ISI Foundation, Turin, Italy
- Laboratory for the Modeling of Biological and Socio-technical Systems, Northeastern University, Boston, MA, USA
| | - Cécile Viboud
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Lidong Gao
- Hunan Workstation for Emerging Infectious Disease Control and Prevention, Chinese Academy of Medical Sciences, Hunan Provincial Center for Disease Control and Prevention, Changsha, China.
| | - Marco Ajelli
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health, Bloomington, IN, USA.
- Laboratory for the Modeling of Biological and Socio-technical Systems, Northeastern University, Boston, MA, USA.
| | - Hongjie Yu
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China.
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Shanghai, China.
- Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China.
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Glynn JR, McLean E, Malava J, Dube A, Katundu C, Crampin AC, Geis S. Effect of Acute Illness on Contact Patterns, Malawi, 2017. Emerg Infect Dis 2021; 26:44-50. [PMID: 31855144 PMCID: PMC6924881 DOI: 10.3201/eid2601.181539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The way persons interact when ill could profoundly affect transmission of infectious agents. To obtain data on these patterns in Africa, we recorded self-reported named contacts and opportunities for casual contact in rural northern Malawi. We interviewed 384 patients and 257 caregivers about contacts over three 24-hour periods: day of the clinic visit for acute illness, the next day, and 2 weeks later when well. For participants of all ages, the number of adult contacts and the proportion using public transportation was higher on the day of the clinic visit than later when well. Compared with the day after the clinic visit, well participants (2 weeks later) named a mean of 0.4 extra contacts; the increase was larger for indoor or prolonged contacts. When well, participants were more likely to visit other houses and congregate settings. When ill, they had more visitors at home. These findings could help refine models of infection spread.
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Mzembe T, Lessells R, Karat AS, Randera-Rees S, Edwards A, Khan P, Tomita A, Tanser F, Baisley K, Grant AD. Prevalence and Risk Factors for Mycobacterium tuberculosis Infection Among Adolescents in Rural South Africa. Open Forum Infect Dis 2021; 8:ofaa520. [PMID: 33511219 PMCID: PMC7814392 DOI: 10.1093/ofid/ofaa520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/21/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND We aimed to estimate the prevalence of and explore risk factors for Mycobacterium tuberculosis infection among adolescents in a high tuberculosis (TB) and human immunodeficiency virus (HIV) prevalence setting. METHODS A cross-sectional study of adolescents (10-19 years) randomly selected from a demographic surveillance area (DSA) in rural KwaZulu-Natal, South Africa. We determined M tuberculosis infection status using the QuantiFERON-TB Gold-plus assay. We used HIV data from the DSA to estimate community-level adult HIV prevalence and random-effects logistic regression to identify risk factors for TB infection. RESULTS We enrolled 1094 adolescents (548 [50.1%] female); M tuberculosis infection prevalence (weighted for nonresponse by age, sex, and urban/rural residence) was 23.0% (95% confidence interval [CI], 20.6-25.6%). Mycobacterium tuberculosis infection was associated with older age (adjusted odds ratio [aOR], 1.37; 95% CI, 1.10-1.71, for increasing age-group [12-14, 15-17, and 18-19 vs 10-11 years]), ever (vs never) having a household TB contact (aOR, 2.13; 95% CI, 1.25-3.64), and increasing community-level HIV prevalence (aOR, 1.43 and 95% CI, 1.07-1.92, for increasing HIV prevalence category [25%-34.9%, 35%-44.9%, ≥45% vs <25%]). CONCLUSIONS Our data support prioritizing TB prevention and care activities in TB-affected households and high HIV prevalence communities.
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Affiliation(s)
- Themba Mzembe
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Richard Lessells
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
- KwaZulu-Natal Research Innovation and Sequencing Platform, University of KwaZulu-Natal, Durban, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), UKZN, Durban, South Africa
| | - Aaron S Karat
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Anita Edwards
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Palwasha Khan
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Interactive Research and Development, Karachi, Pakistan
| | - Andrew Tomita
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- KwaZulu-Natal Research Innovation and Sequencing Platform, University of KwaZulu-Natal, Durban, South Africa
- Centre for Rural Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Frank Tanser
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), UKZN, Durban, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
- Lincoln Institute for Health, University of Lincoln, Lincoln, United Kingdom
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Kathy Baisley
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Alison D Grant
- TB Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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McCreesh N, Dlamini V, Edwards A, Olivier S, Dayi N, Dikgale K, Nxumalo S, Dreyer J, Baisley K, Siedner MJ, White RG, Herbst K, Grant AD, Harling G. Impact of social distancing regulations and epidemic risk perception on social contact and SARS-CoV-2 transmission potential in rural South Africa: analysis of repeated cross-sectional surveys. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.12.01.20241877. [PMID: 33300009 PMCID: PMC7724677 DOI: 10.1101/2020.12.01.20241877] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background South Africa implemented rapid and strict physical distancing regulations to minimize SARS-CoV-2 epidemic spread. Evidence on the impact of such measures on interpersonal contact in rural and lower-income settings is limited. Methods We compared population-representative social contact surveys conducted in the same rural KwaZulu-Natal location once in 2019 and twice in mid-2020. Respondents reported characteristics of physical and conversational ('close interaction') contacts over 24 hours. We built age-mixing matrices and estimated the proportional change in the SARS-CoV-2 reproduction number (R0). Respondents also reported counts of others present at locations visited and transport used, from which we evaluated change in potential exposure to airborne infection due to shared indoor space ('shared air'). Results Respondents in March-December 2019 (n=1704) reported a mean of 7.4 close interaction contacts and 196 shared air person-hours beyond their homes. Respondents in June-July 2020 (n=216), as the epidemic peaked locally, reported 4.1 close interaction contacts and 21 shared air person-hours outside their home, with significant declines in others' homes and public spaces. Adults aged over 50 had fewer close contacts with others over 50, but little change in contact with 15-29 year olds, reflecting ongoing contact within multigenerational households. We estimate potential R0 fell by 42% (95% plausible range 14-59%) between 2019 and June-July 2020. Discussion Extra-household social contact fell substantially following imposition of Covid-19 distancing regulations in rural South Africa. Ongoing contact within intergenerational households highlighted the limitation of social distancing measures in protecting older adults. Funding Wellcome Trust, UKRI, DFID, European Union.
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Affiliation(s)
- Nicky McCreesh
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Vuyiswa Dlamini
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Anita Edwards
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Stephen Olivier
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Njabulo Dayi
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | | | | | - Jaco Dreyer
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Kathy Baisley
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | | | - Richard G. White
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kobus Herbst
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- DSI-MRC South African Population Research Infrastructure Network, South Africa
| | - Alison D. Grant
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- TB Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Laboratory and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Guy Harling
- Africa Health Research Institute, KwaZulu-Natal, South Africa
- Institute for Global Health, University College London, London, United Kingdom
- Department of Epidemiology & Harvard Center for Population and Development Studies, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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Reddy KP, Shebl FM, Foote JHA, Harling G, Scott JA, Panella C, Fitzmaurice KP, Flanagan C, Hyle EP, Neilan AM, Mohareb AM, Bekker LG, Lessells RJ, Ciaranello AL, Wood R, Losina E, Freedberg KA, Kazemian P, Siedner MJ. Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa: a microsimulation modelling study. LANCET GLOBAL HEALTH 2020; 9:e120-e129. [PMID: 33188729 PMCID: PMC7834260 DOI: 10.1016/s2214-109x(20)30452-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/25/2020] [Accepted: 10/06/2020] [Indexed: 12/24/2022]
Abstract
Background Health-care resource constraints in low-income and middle-income countries necessitate the identification of cost-effective public health interventions to address COVID-19. We aimed to develop a dynamic COVID-19 microsimulation model to assess clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal province, South Africa. Methods We compared different combinations of five public health interventions: health-care testing alone, where diagnostic testing is done only for individuals presenting to health-care centres; contact tracing in households of cases; isolation centres, for cases not requiring hospital admission; mass symptom screening and molecular testing for symptomatic individuals by community health-care workers; and quarantine centres, for household contacts who test negative. We calibrated infection transmission rates to match effective reproduction number (Re) estimates reported in South Africa. We assessed two main epidemic scenarios for a period of 360 days, with an Re of 1·5 and 1·2. Strategies with incremental cost-effectiveness ratio (ICER) of less than US$3250 per year of life saved were considered cost-effective. We also did sensitivity analyses by varying key parameters (Re values, molecular testing sensitivity, and efficacies and costs of interventions) to determine the effect on clinical and cost projections. Findings When Re was 1·5, health-care testing alone resulted in the highest number of COVID-19 deaths during the 360-day period. Compared with health-care testing alone, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres reduced mortality by 94%, increased health-care costs by 33%, and was cost-effective (ICER $340 per year of life saved). In settings where quarantine centres were not feasible, a combination of health-care testing, contact tracing, use of isolation centres, and mass symptom screening was cost-effective compared with health-care testing alone (ICER $590 per year of life saved). When Re was 1·2, health-care testing, contact tracing, use of isolation centres, and use of quarantine centres was the least costly strategy, and no other strategies were cost-effective. In sensitivity analyses, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres was generally cost-effective, with the exception of scenarios in which Re was 2·6 and when efficacies of isolation centres and quarantine centres for transmission reduction were reduced. Interpretation In South Africa, strategies involving household contact tracing, isolation, mass symptom screening, and quarantining household contacts who test negative would substantially reduce COVID-19 mortality and would be cost-effective. The optimal combination of interventions depends on epidemic growth characteristics and practical implementation considerations. Funding US National Institutes of Health, Royal Society, Wellcome Trust.
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Affiliation(s)
- Krishna P Reddy
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - Fatma M Shebl
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Julia H A Foote
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Guy Harling
- Department of Epidemiology, Harvard T H Chan School of Public Health, Boston, MA, USA; Harvard Center for Population and Development Studies, Harvard T H Chan School of Public Health, Boston, MA, USA; Africa Health Research Institute, Durban, South Africa; Institute for Global Health, University College London, London, UK; MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), University of Witwatersrand, Johannesburg, South Africa
| | - Justine A Scott
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Christopher Panella
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Kieran P Fitzmaurice
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Clare Flanagan
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Emily P Hyle
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Harvard University Center for AIDS Research, Cambridge, MA, USA
| | - Anne M Neilan
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Division of General Academic Pediatrics, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Amir M Mohareb
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Linda-Gail Bekker
- Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa
| | - Richard J Lessells
- KwaZulu-Natal Research Innovation and Sequencing, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Andrea L Ciaranello
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Harvard University Center for AIDS Research, Cambridge, MA, USA
| | - Robin Wood
- Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa
| | - Elena Losina
- Harvard Medical School, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA; Orthopaedic and Arthritis Center for Outcomes Research and Policy and Innovation eValuation in Orthopaedic Treatments (PIVOT) Center, Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Kenneth A Freedberg
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Division of General Internal Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Department of Health Policy and Management, Harvard T H Chan School of Public Health, Boston, MA, USA
| | - Pooyan Kazemian
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Mark J Siedner
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Africa Health Research Institute, Durban, South Africa
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Hu S, Wang W, Wang Y, Litvinova M, Luo K, Ren L, Sun Q, Chen X, Zeng G, Li J, Liang L, Deng Z, Zheng W, Li M, Yang H, Guo J, Wang K, Chen X, Liu Z, Yan H, Shi H, Chen Z, Zhou Y, Sun K, Vespignani A, Viboud C, Gao L, Ajelli M, Yu H. Infectivity, susceptibility, and risk factors associated with SARS-CoV-2 transmission under intensive contact tracing in Hunan, China. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020. [PMID: 32793929 DOI: 10.1101/2020.07.23.20160317] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Several mechanisms driving SARS-CoV-2 transmission remain unclear. Based on individual records of 1,178 SARS-CoV-2 infectors and their 15,648 contacts in Hunan, China, we estimated key transmission parameters. The mean generation time was estimated to be 5.7 (median: 5.5, IQR: 4.5, 6.8) days, with infectiousness peaking 1.8 days before symptom onset, with 95% of transmission events occurring between 8.8 days before and 9.5 days after symptom onset. Most of transmission events occurred during the pre-symptomatic phase (59.2%). SARS-CoV-2 susceptibility to infection increases with age, while transmissibility is not significantly different between age groups and between symptomatic and asymptomatic individuals. Contacts in households and exposure to first-generation cases are associated with higher odds of transmission. Our findings support the hypothesis that children can effectively transmit SARS-CoV-2 and highlight how pre-symptomatic and asymptomatic transmission can hinder control efforts.
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43
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Thindwa D, Pinsent A, Ojal J, Gallagher KE, French N, Flasche S. Vaccine strategies to reduce the burden of pneumococcal disease in HIV-infected adults in Africa. Expert Rev Vaccines 2020; 19:1085-1092. [PMID: 33269987 PMCID: PMC8315211 DOI: 10.1080/14760584.2020.1843435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Streptococcus pneumoniae is the leading cause of invasive bacterial disease, globally. Despite antiretroviral therapy, adults infected with human immunodeficiency virus (HIV) are also at high risk of pneumococcal carriage and disease. Pneumococcal conjugate vaccines (PCVs) provide effective protection against vaccine serotype (VT) carriage and disease in children, and have been introduced worldwide, including most HIV-affected low- and middle-income countries. Unlike high-income countries, the circulation of VT persists in the PCV era in some low-income countries and results in a continued high burden of pneumococcal disease in HIV-infected adults. Moreover, no routine vaccination that directly protects HIV-infected adults in such settings has been implemented. AREAS COVERED Nonsystematic review on the pneumococcal burden in HIV-infected adults and vaccine strategies to reduce this burden. EXPERT OPINION We propose and discuss the relative merit of changing the infant PCV program to use (1a) a two prime plus booster dose schedule, (1b) a two prime plus booster dose schedule with an additional booster dose at school entry, to directly vaccinate (2a) HIV-infected adults or vaccinating (2b) HIV-infected pregnant women for direct protection, with added indirect protection to the high-risk neonates. We identify key knowledge gaps for such an evaluation and propose strategies to overcome them.
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Affiliation(s)
- Deus Thindwa
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK,Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK,Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi,CONTACT Deus Thindwa Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, United Kingdom
| | - Amy Pinsent
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK,Aquarius Population Health, London, UK
| | - John Ojal
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK,Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK,Epidemiology and Demography Department, KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine, Coast, Kilifi, Kenya
| | - Katherine E Gallagher
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Neil French
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi,Institute of Infection and Global Health, Department of Clinical Infection, Microbiology, and Immunology, University of Liverpool, Liverpool, UK
| | - Stefan Flasche
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK,Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
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44
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Sloot R, Shanaube K, Claassens M, Telisinghe L, Schaap A, Godfrey-Faussett P, Ayles H, Floyd S. Interpretation of serial interferon-gamma test results to measure new tuberculosis infection among household contacts in Zambia and South Africa. BMC Infect Dis 2020; 20:760. [PMID: 33059620 PMCID: PMC7559914 DOI: 10.1186/s12879-020-05483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 10/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A more stringent QuantiFERON-TB Gold In-Tube (QFT) conversion (from negative to positive) definition has been proposed to allow more definite detection of recent tuberculosis (TB) infection. We explored alternative conversion definitions to assist the interpretation of serial QFT results and estimate incidence of TB infection in a large cohort study. METHODS We used QFT serial results from TB household contacts aged ≥15 years, collected at baseline and during two follow-up visits (2006-2011) as part of a cohort study in 24 communities in Zambia and South Africa (SA). Conversion rates using the manufacturers' definition (interferon-gamma (IFN-g) < 0.35 to ≥0.35, 'def1') were compared with stricter definitions (IFN-g < 0.2 to ≥0.7 IU/ml, 'def2'; IFN-g < 0.2 to ≥1.05 IU/ml, 'def3'; IFN-g < 0.2 to ≥1.4 IU/ml, 'def4'). Poisson regression was used for analysis. RESULTS One thousand three hundred sixty-five individuals in Zambia and 822 in SA had QFT results available. Among HIV-negative individuals, the QFT conversion rate was 27.4 per 100 person-years (CI:22.9-32.6) using def1, 19.0 using def2 (CI:15.2-23.7), 14.7 using def3 (CI:11.5-18.8), and 12.0 using def4 (CI:9.2-15.7). Relative differences across def1-def4 were similar in Zambia and SA. Using def1, conversion was less likely if HIV positive not on antiretroviral treatment compared to HIV negative (aRR = 0.7, 95%CI = 0.4-0.9), in analysis including both countries. The same direction of associations were found using def 2-4. CONCLUSION High conversion rates were found even with the strictest definition, indicating high incidence of TB infection among household contacts of TB patients in these communities. The trade-off between sensitivity and specificity using different thresholds of QFT conversion remains unknown due to the absence of a reference standard. However, we identified boundaries within which an appropriate definition might fall, and our strictest definition plausibly has high specificity.
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Affiliation(s)
- Rosa Sloot
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
| | - Kwame Shanaube
- Zambart, School of Medicine, University of Zambia, Lusaka, Zambia
| | - Mareli Claassens
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Lily Telisinghe
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Ab Schaap
- Zambart, School of Medicine, University of Zambia, Lusaka, Zambia
| | - Peter Godfrey-Faussett
- UNAIDS, Geneva, Switzerland.,Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Helen Ayles
- Zambart, School of Medicine, University of Zambia, Lusaka, Zambia.,Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Sian Floyd
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
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45
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Reddy KP, Shebl FM, Foote JHA, Harling G, Scott JA, Panella C, Fitzmaurice KP, Flanagan C, Hyle EP, Neilan AM, Mohareb AM, Bekker LG, Lessells RJ, Ciaranello AL, Wood R, Losina E, Freedberg KA, Kazemian P, Siedner MJ. Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa: a microsimulation modelling study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020. [PMID: 32637979 PMCID: PMC7340205 DOI: 10.1101/2020.06.29.20140111] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background Healthcare resource constraints in low and middle-income countries necessitate selection of cost-effective public health interventions to address COVID-19. Methods We developed a dynamic COVID-19 microsimulation model to evaluate clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal, South Africa. Interventions assessed were Healthcare Testing (HT), where diagnostic testing is performed only for those presenting to healthcare centres; Contact Tracing (CT) in households of cases; Isolation Centres (IC), for cases not requiring hospitalisation; community health worker-led Mass Symptom Screening and molecular testing for symptomatic individuals (MS); and Quarantine Centres (QC), for household contacts who test negative. Given uncertainties about epidemic dynamics in South Africa, we evaluated two main epidemic scenarios over 360 days, with effective reproduction numbers (Re) of 1·5 and 1·2. We compared HT, HT+CT, HT+CT+IC, HT+CT+IC+MS, HT+CT+IC+QC, and HT+CT+IC+MS+QC, considering strategies with incremental cost-effectiveness ratio (ICER) <US$3,250/year-of-life saved (YLS) cost-effective. In sensitivity analyses, we varied Re, molecular testing sensitivity, and efficacies and costs of interventions. Findings With Re 1·5, HT resulted in the most COVID-19 deaths over 360 days. Compared with HT, HT+CT+IC+MS+QC reduced mortality by 94%, increased costs by 33%, and was cost-effective (ICER $340/YLS). In settings where quarantine centres cannot be implemented, HT+CT+IC+MS was cost-effective compared with HT (ICER $590/YLS). With Re 1·2, HT+CT+IC+QC was the least costly strategy, and no other strategy was cost-effective. HT+CT+IC+MS+QC was cost-effective in many sensitivity analyses; notable exceptions were when Re was 2·6 and when efficacies of ICs and QCs for transmission reduction were reduced. Interpretation In South Africa, strategies involving household contact tracing, isolation, mass symptom screening, and quarantining household contacts who test negative would substantially reduce COVID-19 mortality and be cost-effective. The optimal combination of interventions depends on epidemic growth characteristics and practical implementation considerations.
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Affiliation(s)
- Krishna P Reddy
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Fatma M Shebl
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Julia H A Foote
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Guy Harling
- Department of Epidemiology and Harvard Center for Population & Development Studies, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Africa Health Research Institute, KwaZulu-Natal, South Africa.,Institute for Global Health, University College London, London, UK.,MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), University of Witwatersrand, South Africa
| | - Justine A Scott
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Christopher Panella
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Kieran P Fitzmaurice
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Clare Flanagan
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA
| | - Emily P Hyle
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.,Harvard University Center for AIDS Research, Cambridge, MA, USA
| | - Anne M Neilan
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.,Division of General Academic Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - Amir M Mohareb
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Linda-Gail Bekker
- Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa
| | - Richard J Lessells
- KwaZulu-Natal Research Innovation and Sequencing (KRISP), College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Andrea L Ciaranello
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.,Harvard University Center for AIDS Research, Cambridge, MA, USA
| | - Robin Wood
- Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa
| | - Elena Losina
- Harvard Medical School, Boston, MA, USA.,Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.,Orthopedic and Arthritis Center for Outcomes Research (OrACORe), Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.,Policy and Innovation eValuation in Orthopedic Treatments (PIVOT) Center, Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Kenneth A Freedberg
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.,Division of General Internal Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Pooyan Kazemian
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Mark J Siedner
- Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Africa Health Research Institute, KwaZulu-Natal, South Africa.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
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46
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Harris RC, Sumner T, Knight GM, Zhang H, White RG. Potential impact of tuberculosis vaccines in China, South Africa, and India. Sci Transl Med 2020; 12:eaax4607. [PMID: 33028708 DOI: 10.1126/scitranslmed.aax4607] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 11/12/2019] [Accepted: 09/16/2020] [Indexed: 12/11/2022]
Abstract
More effective tuberculosis vaccines are needed to help reach World Health Organization tuberculosis elimination goals. Insufficient evidence exists on the potential impact of future tuberculosis vaccines with varying characteristics and in different epidemiological settings. To inform vaccine development decision making, we modeled the impact of hypothetical tuberculosis vaccines in three high-burden countries. We calibrated Mycobacterium tuberculosis (M.tb) transmission models to age-stratified demographic and epidemiological data from China, South Africa, and India. We varied vaccine efficacy to prevent infection or disease, effective in persons M.tb uninfected or infected, and duration of protection. We modeled routine early-adolescent vaccination and 10-yearly mass campaigns from 2025. We estimated median percentage population-level tuberculosis incidence rate reduction (IRR) in 2050 compared to a no new vaccine scenario. In all settings, results suggested vaccines preventing disease in M.tb-infected populations would have greatest impact by 2050 (10-year, 70% efficacy against disease, IRR 51%, 52%, and 54% in China, South Africa, and India, respectively). Vaccines preventing reinfection delivered lower potential impact (IRR 1, 12, and 17%). Intermediate impact was predicted for vaccines effective only in uninfected populations, if preventing infection (IRR 21, 37, and 50%) or disease (IRR 19, 36, and 51%), with greater impact in higher-transmission settings. Tuberculosis vaccines have the potential to deliver substantial population-level impact. For prioritizing impact by 2050, vaccine development should focus on preventing disease in M.tb-infected populations. Preventing infection or disease in uninfected populations may be useful in higher transmission settings. As vaccine impact depended on epidemiology, different development strategies may be required.
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Affiliation(s)
- Rebecca C Harris
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
| | - Tom Sumner
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Gwenan M Knight
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Hui Zhang
- Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Richard G White
- TB Modelling Group, TB Centre and Centre for the Mathematical Modelling of Infectious Diseases, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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47
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Siedner MJ, Kraemer JD, Meyer MJ, Harling G, Mngomezulu T, Gabela P, Dlamini S, Gareta D, Majozi N, Ngwenya N, Seeley J, Wong E, Iwuji C, Shahmanesh M, Hanekom W, Herbst K. Access to primary healthcare during lockdown measures for COVID-19 in rural South Africa: an interrupted time series analysis. BMJ Open 2020; 10:e043763. [PMID: 33020109 PMCID: PMC7536636 DOI: 10.1136/bmjopen-2020-043763] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/13/2020] [Accepted: 09/18/2020] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVES We evaluated whether implementation of lockdown orders in South Africa affected ambulatory clinic visitation in rural Kwa-Zulu Natal (KZN). DESIGN Observational cohort SETTING: Data were analysed from 11 primary healthcare clinics in northern KZN. PARTICIPANTS A total of 46 523 individuals made 89 476 clinic visits during the observation period. EXPOSURE OF INTEREST We conducted an interrupted time series analysis to estimate changes in clinic visitation with a focus on transitions from the prelockdown to the level 5, 4 and 3 lockdown periods. OUTCOME MEASURES Daily clinic visitation at ambulatory clinics. In stratified analyses, we assessed visitation for the following subcategories: child health, perinatal care and family planning, HIV services, non-communicable diseases and by age and sex strata. RESULTS We found no change in total clinic visits/clinic/day at the time of implementation of the level 5 lockdown (change from 90.3 to 84.6 mean visits/clinic/day, 95% CI -16.5 to 3.1), or at the transitions to less stringent level 4 and 3 lockdown levels. We did detect a >50% reduction in child healthcare visits at the start of the level 5 lockdown from 11.9 to 4.7 visits/day (-7.1 visits/clinic/day, 95% CI -8.9 to 5.3), both for children aged <1 year and 1-5 years, with a gradual return to prelockdown within 3 months after the first lockdown measure. In contrast, we found no drop in clinic visitation in adults at the start of the level 5 lockdown, or related to HIV care (from 37.5 to 45.6, 8.0 visits/clinic/day, 95% CI 2.1 to 13.8). CONCLUSIONS In rural KZN, we identified a significant, although temporary, reduction in child healthcare visitation but general resilience of adult ambulatory care provision during the first 4 months of the lockdown. Future work should explore the impacts of the circulating epidemic on primary care provision and long-term impacts of reduced child visitation on outcomes in the region.
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Affiliation(s)
- Mark J Siedner
- Clinical Research Department, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - John D Kraemer
- Department of Health Systems Administration, Georgetown University, Washington, District of Columbia, USA
| | - Mark J Meyer
- Department of Mathematics and Statistics, Georgetown University, Washington, District of Columbia, USA
| | - Guy Harling
- Institute for Global Health, University College London, London, UK
- Department of Social Sciences, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Thobeka Mngomezulu
- Department of Population Research, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Patrick Gabela
- Department of Population Research, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Siphephelo Dlamini
- Department of Nursing, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Dickman Gareta
- Research Data Management, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Nomathamsanqa Majozi
- Public Engagement, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Nothando Ngwenya
- Department of Social Sciences, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Janet Seeley
- Research Unit on AIDS, Medical Research Council and Ugandan Virus Research Institute, Entebbe, Uganda
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Emily Wong
- Clinical Research Department, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Collins Iwuji
- Department of Sexual Health and HIV Medicine, Brighton and Sussex Medical School, Brighton, Brighton and Hove, UK
| | - Maryam Shahmanesh
- Clinical Research Department, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Willem Hanekom
- Clinical Research Department, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
| | - Kobus Herbst
- Department of Population Research, Africa Health Research Institute, Durban, Kwa-Zulu Natal, South Africa
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48
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Quaife M, van Zandvoort K, Gimma A, Shah K, McCreesh N, Prem K, Barasa E, Mwanga D, Kangwana B, Pinchoff J, Edmunds WJ, Jarvis CI, Austrian K. The impact of COVID-19 control measures on social contacts and transmission in Kenyan informal settlements. BMC Med 2020; 18:316. [PMID: 33012285 PMCID: PMC7533154 DOI: 10.1186/s12916-020-01779-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/09/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many low- and middle-income countries have implemented control measures against coronavirus disease 2019 (COVID-19). However, it is not clear to what extent these measures explain the low numbers of recorded COVID-19 cases and deaths in Africa. One of the main aims of control measures is to reduce respiratory pathogen transmission through direct contact with others. In this study, we collect contact data from residents of informal settlements around Nairobi, Kenya, to assess if control measures have changed contact patterns, and estimate the impact of changes on the basic reproduction number (R0). METHODS We conducted a social contact survey with 213 residents of five informal settlements around Nairobi in early May 2020, 4 weeks after the Kenyan government introduced enhanced physical distancing measures and a curfew between 7 pm and 5 am. Respondents were asked to report all direct physical and non-physical contacts made the previous day, alongside a questionnaire asking about the social and economic impact of COVID-19 and control measures. We examined contact patterns by demographic factors, including socioeconomic status. We described the impact of COVID-19 and control measures on income and food security. We compared contact patterns during control measures to patterns from non-pandemic periods to estimate the change in R0. RESULTS We estimate that control measures reduced physical contacts by 62% and non-physical contacts by either 63% or 67%, depending on the pre-COVID-19 comparison matrix used. Masks were worn by at least one person in 92% of contacts. Respondents in the poorest socioeconomic quintile reported 1.5 times more contacts than those in the richest. Eighty-six percent of respondents reported a total or partial loss of income due to COVID-19, and 74% reported eating less or skipping meals due to having too little money for food. CONCLUSION COVID-19 control measures have had a large impact on direct contacts and therefore transmission, but have also caused considerable economic and food insecurity. Reductions in R0 are consistent with the comparatively low epidemic growth in Kenya and other sub-Saharan African countries that implemented similar, early control measures. However, negative and inequitable impacts on economic and food security may mean control measures are not sustainable in the longer term.
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Affiliation(s)
- Matthew Quaife
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK.
| | - Kevin van Zandvoort
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Amy Gimma
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Kashvi Shah
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Nicky McCreesh
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Kiesha Prem
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Edwine Barasa
- Health Economics Research Unit, KEMRI-Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | | | | | | | - W John Edmunds
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Christopher I Jarvis
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
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49
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Abstract
BACKGROUND Researchers increasingly use social contact data to inform models for infectious disease spread with the aim of guiding effective policies about disease prevention and control. In this article, we undertake a systematic review of the study design, statistical analyses, and outcomes of the many social contact surveys that have been published. METHODS We systematically searched PubMed and Web of Science for articles regarding social contact surveys. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines as closely as possible. RESULTS In total, we identified 64 social contact surveys, with more than 80% of the surveys conducted in high-income countries. Study settings included general population (58%), schools or universities (37%), and health care/conference/research institutes (5%). The largest number of studies did not focus on a specific age group (38%), whereas others focused on adults (32%) or children (19%). Retrospective (45%) and prospective (41%) designs were used most often with 6% using both for comparison purposes. The definition of a contact varied among surveys, e.g., a nonphysical contact may require conversation, close proximity, or both. We identified age, time schedule (e.g., weekday/weekend), and household size as relevant determinants of contact patterns across a large number of studies. CONCLUSIONS We found that the overall features of the contact patterns were remarkably robust across several countries, and irrespective of the study details. By considering the most common approach in each aspect of design (e.g., sampling schemes, data collection, definition of contact), we could identify recommendations for future contact data surveys that may be used to facilitate comparison between studies.
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50
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Siedner MJ, Harling G, Derache A, Smit T, Khoza T, Gunda R, Mngomezulu T, Gareta D, Majozi N, Ehlers E, Dreyer J, Nxumalo S, Dayi N, Ording-Jesperson G, Ngwenya N, Wong E, Iwuji C, Shahmanesh M, Seeley J, De Oliveira T, Ndung'u T, Hanekom W, Herbst K. Protocol: Leveraging a demographic and health surveillance system for Covid-19 Surveillance in rural KwaZulu-Natal. Wellcome Open Res 2020; 5:109. [PMID: 32802963 PMCID: PMC7424917 DOI: 10.12688/wellcomeopenres.15949.2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2020] [Indexed: 12/28/2022] Open
Abstract
A coordinated system of disease surveillance will be critical to effectively control the coronavirus disease 2019 (Covid-19) pandemic. Such systems enable rapid detection and mapping of epidemics and inform allocation of scarce prevention and intervention resources. Although many lower- and middle-income settings lack infrastructure for optimal disease surveillance, health and demographic surveillance systems (HDSS) provide a unique opportunity for epidemic monitoring. This protocol describes a surveillance program at the Africa Health Research Institute's Population Intervention Platform site in northern KwaZulu-Natal. The program leverages a longstanding HDSS in a rural, resource-limited setting with very high prevalence of HIV and tuberculosis to perform Covid-19 surveillance. Our primary aims include: describing the epidemiology of the Covid-19 epidemic in rural KwaZulu-Natal; determining the impact of the Covid-19 outbreak and non-pharmaceutical control interventions (NPI) on behaviour and wellbeing; determining the impact of HIV and tuberculosis on Covid-19 susceptibility; and using collected data to support the local public-sector health response. The program involves telephone-based interviews with over 20,000 households every four months, plus a sub-study calling 750 households every two weeks. Each call asks a household representative how the epidemic and NPI are affecting the household and conducts a Covid-19 risk screen for all resident members. Any individuals screening positive are invited to a clinical screen, potential test and referral to necessary care - conducted in-person near their home following careful risk minimization procedures. In this protocol we report the details of our cohort design, questionnaires, data and reporting structures, and standard operating procedures in hopes that our project can inform similar efforts elsewhere.
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Affiliation(s)
- Mark J. Siedner
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Guy Harling
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Institute for Global Health, University College London, London, UK
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), University of the Witwatersrand, Johannesburg, South Africa
- Department of Epidemiology and Harvard Center for Population and Development Studies, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Anne Derache
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Theresa Smit
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Thandeka Khoza
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Resign Gunda
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | | | - Dickman Gareta
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | | | - Eugene Ehlers
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Jaco Dreyer
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Siyabonga Nxumalo
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Njabulo Dayi
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | | | - Nothando Ngwenya
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
| | - Emily Wong
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Collins Iwuji
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | - Maryam Shahmanesh
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Institute for Global Health, University College London, London, UK
| | - Janet Seeley
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Global Health and Development Department, London School of Hygiene & Tropical Medicine, London, UK
| | - Tulio De Oliveira
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP)), School of Laboratory Medicine and Medical Sciences, University of KwaZulu Natal, Durban, KwaZulu-Natal, South Africa
- Department of Global Health, University of Washington, Seattle, USA
| | - Thumbi Ndung'u
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Division of Infection and Immunity, University College London, London, UK
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu Natal, Durban, KwaZulu-Natal, South Africa
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Willem Hanekom
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- Division of Infection and Immunity, University College London, London, UK
| | - Kobus Herbst
- Africa Health Research Institute, Durban, KwaZulu-Natal, South Africa
- SAPRIN, South African Medical Research Council, Cape Town, South Africa
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