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Lower frequency and letality in women and in altitude due to COVID-19: Two sides of the same coin. Arch Bronconeumol 2021; 57:70-72. [PMID: 34629669 PMCID: PMC7927644 DOI: 10.1016/j.arbres.2021.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Fine-scale family structure shapes influenza transmission risk in households: Insights from primary schools in Matsumoto city, 2014/15. PLoS Comput Biol 2019; 15:e1007589. [PMID: 31877122 PMCID: PMC6959609 DOI: 10.1371/journal.pcbi.1007589] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 01/14/2020] [Accepted: 12/08/2019] [Indexed: 12/19/2022] Open
Abstract
Households are important settings for the transmission of seasonal influenza. Previous studies found that the per-person risk of within-household transmission decreases with household size. However, more detailed heterogeneities driven by household composition and contact patterns have not been studied. We employed a mathematical model that accounts for infections both from outside and within the household. The model was applied to citywide primary school seasonal influenza surveillance and household surveys from 10,486 students during the 2014/15 season in Matsumoto city, Japan. We compared a range of models to estimate the structure of household transmission and found that familial relationship and household composition strongly influenced the transmission patterns of seasonal influenza in households. Children had a substantially high risk of infection from outside the household (up to 20%) compared with adults (1–3%). Intense transmission was observed within-generation (between children/parents/grandparents) and also between mother and child, with transmission risks typically ranging from 5–20% depending on the transmission route and household composition. Children were identified as the largest source of secondary transmission, with family structure influencing infection risk. We characterised detailed heterogeneity in household transmission patterns of influenza by applying a mathematical model to citywide primary school influenza survey data from 10,486 students in Matsumoto city, Japan, one of the largest-scale household surveys on seasonal influenza. Children were identified as the largest source of secondary transmission, with family structure influencing infection risk. This suggests that vaccinating children would have stronger secondary effects on transmission than would be assumed without taking into account transmission patterns within the household.
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Affiliation(s)
- Jennifer E Schuster
- Department of Pediatrics, Children's Mercy Kansas City, 2401 Gillham Road, Kansas City, MO 64108, USA.
| | - John V Williams
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, 9122 Rangos Research Building, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
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Nelson KN, Grijalva CG, Chochua S, Hawkins PA, Gil AI, Lanata CF, Griffin MR, Edwards KM, Klugman KP, Vidal JE. Dynamics of Colonization of Streptococcus pneumoniae Strains in Healthy Peruvian Children. Open Forum Infect Dis 2018; 5:ofy039. [PMID: 29588913 PMCID: PMC5842394 DOI: 10.1093/ofid/ofy039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/14/2018] [Indexed: 12/21/2022] Open
Abstract
Background Although asymptomatic carriage of Streptococcus pneumoniae (Spn) is common, acquisition of the bacteria is the first step in disease pathogenesis. We examined the effect of introduction of the 7-valent pneumococcal vaccine on Spn carriage patterns in a cohort of Peruvian children. Methods We used data from a prospective cohort study that collected monthly nasopharyngeal samples from children under 3 years of age. Spn isolates were serotyped using Quellung reactions, and bacterial density was determined by quantitative polymerase chain reaction. Changes in Spn carriage patterns, including the rate of carriage and number and density of serotypes carried over time, were evaluated before (2009) and after widespread vaccination with PCV7 (2011). Using all pneumococcal detections from each child and year, we identified serotypes that were present both at first and last detection as “persisters” and serotypes that replaced a different earlier type and were detected last as “recolonizers.” Results Ninety-two percent (467/506) of children in 2009 and 89% (451/509) in 2011 carried Spn at least once. In 2009 and 2011, rates of carriage were 9.03 and 9.04 Spn detections per person-year, respectively. In 2009, 23F, a serotype included in PCV7, was the only type identified as a persister and 6A, 15B, and 19A were identified as recolonizer serotypes. In 2011, 6B and 7C were persister serotypes and 13 was a frequent recolonizer serotype. Conclusions Overall Spn carriage among children under 3 in Peru was similar before and after introduction of PCV7; however, serotype-specific rates and longitudinal carriage patterns have shifted.
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Affiliation(s)
- Kristin N Nelson
- Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia
| | - Carlos G Grijalva
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, Tennessee
| | - Sopio Chochua
- Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia
| | - Paulina A Hawkins
- Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia
| | - Ana I Gil
- Instituto de Investigación Nutricional, Lima, Perú
| | | | - Marie R Griffin
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, Tennessee
| | - Kathryn M Edwards
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, Tennessee
| | - Keith P Klugman
- Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia.,Bill and Melinda Gates Foundation, Seattle, Washington
| | - Jorge E Vidal
- Department of Global Health, Emory University Rollins School of Public Health, Atlanta, Georgia
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Howard LM, Johnson M, Gil AI, Pekosz A, Griffin MR, Edwards KM, Lanata CF, Grijalva CG, Williams JV. A novel real-time RT-PCR assay for influenza C tested in Peruvian children. J Clin Virol 2017; 96:12-16. [PMID: 28917132 PMCID: PMC5901714 DOI: 10.1016/j.jcv.2017.08.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/19/2017] [Accepted: 08/24/2017] [Indexed: 12/04/2022]
Abstract
BACKGROUND Influenza C virus (ICV) is associated with acute respiratory illness. Yet ICV remains under recognized, with most previous studies using only culture to identify cases. OBJECTIVES To develop a sensitive and specific real-time RT-PCR assay for ICV that allows for rapid and accurate detection in a clinical or research setting. STUDY DESIGN Multiple ICV sequences obtained from GenBank were analyzed, including 141 hemagglutinin-esterase (HE), 106 matrix (M), and 97 nucleoprotein (NP) sequences. Primers and probes were designed based on conserved regions. Multiple primer-probe sets were tested against multiple ICV strains. RESULTS The ICV M and NP genes offered the most conserved sequence regions. Primers and probes based on newer sequence data offered enhanced detection of ICV, especially for low titer specimens. An NP-targeted assay yielded the best performance and was capable of detecting 10-100 RNA copies per reaction. The NP assay detected multiple clinical isolates of ICV collected in a field epidemiology study conducted in Peru. CONCLUSIONS We report a new real-time RT-PCR assay for ICV with high sensitivity and specificity.
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Affiliation(s)
- Leigh M Howard
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, United States; Vanderbilt Vaccine Research Program, Nashville, TN, United States
| | - Monika Johnson
- Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of UPMC, United States
| | - Ana I Gil
- Instituto de Investigacion Nutricional, Lima, Peru
| | - Andrew Pekosz
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, United States
| | - Marie R Griffin
- Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Kathryn M Edwards
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, United States; Vanderbilt Vaccine Research Program, Nashville, TN, United States
| | - Claudio F Lanata
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, United States; Instituto de Investigacion Nutricional, Lima, Peru
| | - Carlos G Grijalva
- Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - John V Williams
- Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of UPMC, United States.
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Tinoco YO, Azziz-Baumgartner E, Uyeki TM, Rázuri HR, Kasper MR, Romero C, Silva ME, Simons MP, Soto GM, Widdowson MA, Gilman RH, Bausch DG, Montgomery JM. Burden of Influenza in 4 Ecologically Distinct Regions of Peru: Household Active Surveillance of a Community Cohort, 2009-2015. Clin Infect Dis 2017; 65:1532-1541. [PMID: 29020267 PMCID: PMC5850002 DOI: 10.1093/cid/cix565] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/22/2017] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND There are limited data on the burden of disease posed by influenza in low- and middle-income countries. Furthermore, most estimates of influenza disease burden worldwide rely on passive sentinel surveillance at health clinics and hospitals that lack accurate population denominators. METHODS We documented influenza incidence, seasonality, health-system utilization with influenza illness, and vaccination coverage through active community-based surveillance in 4 ecologically distinct regions of Peru over 6 years. Approximately 7200 people in 1500 randomly selected households were visited 3 times per week. Naso- and oropharyngeal swabs were collected from persons with influenza-like illness and tested for influenza virus by real-time reverse-transcription polymerase chain reaction. RESULTS We followed participants for 35353 person-years (PY). The overall incidence of influenza was 100 per 1000 PY (95% confidence interval [CI], 97-104) and was highest in children aged 2-4 years (256/1000 PY [95% CI, 236-277]). Seasonal incidence trends were similar across sites, with 61% of annual influenza cases occurring during the austral winter (May-September). Of all participants, 44 per 1000 PY (95% CI, 42-46) sought medical care, 0.7 per 1000 PY (95% CI, 0.4-1.0) were hospitalized, and 1 person died (2.8/100000 PY). Influenza vaccine coverage was 27% among children aged 6-23 months and 26% among persons aged ≥65 years. CONCLUSIONS Our results indicate that 1 in 10 persons develops influenza each year in Peru, with the highest incidence in young children. Active community-based surveillance allows for a better understanding of the true burden and seasonality of disease that is essential to plan the optimal target groups, timing, and cost of national influenza vaccination programs.
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Affiliation(s)
- Yeny O Tinoco
- US Naval Medical Research Unit No. 6, Bellavista, Peru
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | | | - Timothy M Uyeki
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Hugo R Rázuri
- US Naval Medical Research Unit No. 6, Bellavista, Peru
| | | | | | - Maria E Silva
- US Naval Medical Research Unit No. 6, Bellavista, Peru
| | - Mark P Simons
- US Naval Medical Research Unit No. 6, Bellavista, Peru
| | | | - Marc-Alain Widdowson
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Robert H Gilman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Daniel G Bausch
- US Naval Medical Research Unit No. 6, Bellavista, Peru
- Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana; and
| | - Joel M Montgomery
- US Naval Medical Research Unit No. 6, Bellavista, Peru
- Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia
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Howard LM, Fan R, Zhu Y, Griffin MR, Edwards KM, Hartinger S, Williams JV, Vidal JE, Klugman KP, Gil AI, Lanata CF, Grijalva CG. Nasopharyngeal Pneumococcal Density Is Associated With Viral Activity but Not With Use of Improved Stoves Among Young Andean Children. Open Forum Infect Dis 2017; 4:ofx161. [PMID: 28929126 PMCID: PMC5601081 DOI: 10.1093/ofid/ofx161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/20/2017] [Indexed: 12/15/2022] Open
Abstract
Background Indoor smoke exposure is common in developing countries and may influence nasopharyngeal (NP) pneumococcal colonization density and risk of acute respiratory illness. We compared colonization density among Andean children living in households previously enrolled in a randomized controlled trial of a home intervention package including improved stoves to reduce smoke, kitchen sinks, and water disinfection. Methods We enrolled 260 children aged <3 years and made weekly household visits to assess for acute respiratory illness (ARI) and collect nasal swabs for respiratory virus polymerase chain reaction (PCR) testing during ARI. At monthly intervals, NP swabs were collected to determine pneumococcal colonization density through quantitative lytA PCR. We used linear quantile mixed-effects models to compare median log-transformed colonization densities among children in households randomized to the control (n = 129) versus intervention (n = 131) in sequential time points, accounting for random effects of multiple samples from individual children. Other covariates included age, sex, month, antibiotic exposure, and timing of sample collection relative to ARI with and without viral detection. Results Age and sociodemographic characteristics were similar between groups. Although no differences were observed in densities between groups, colonization density varied significantly over time in both groups, with highest densities coinciding with spring months. Time during and after virus-associated ARI was also associated with higher pneumococcal colonization density than time remote from ARIs. Conclusions A home intervention package, including improved stoves, was not associated with changes in pneumococcal densities in young Andean children. However, increasing pneumococcal density was observed with spring season and viral-associated ARIs.
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Affiliation(s)
- Leigh M Howard
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Vanderbilt Vaccine Research Program, Nashville, Tennessee
| | | | | | - Marie R Griffin
- Department of Health Policy, Vanderbilt University, Nashville, Tennessee
| | - Kathryn M Edwards
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Vanderbilt Vaccine Research Program, Nashville, Tennessee
| | - Stella Hartinger
- Universidad Peruana Cayetano Heredia, Lima, Peru.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - John V Williams
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pennsylvania
| | - Jorge E Vidal
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Ana I Gil
- Instituto de Investigacion Nutricional, Lima, Peru
| | - Claudio F Lanata
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Instituto de Investigacion Nutricional, Lima, Peru
| | - Carlos G Grijalva
- Department of Health Policy, Vanderbilt University, Nashville, Tennessee
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Reese H, Routray P, Torondel B, Sclar G, Delea MG, Sinharoy SS, Zambrano L, Caruso B, Mishra SR, Chang HH, Clasen T. Design and rationale of a matched cohort study to assess the effectiveness of a combined household-level piped water and sanitation intervention in rural Odisha, India. BMJ Open 2017; 7:e012719. [PMID: 28363920 PMCID: PMC5387990 DOI: 10.1136/bmjopen-2016-012719] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Government efforts to address massive shortfalls in rural water and sanitation in India have centred on construction of community water sources and toilets for selected households. However, deficiencies with water quality and quantity at the household level and community coverage and actual use of toilets have led Gram Vikas, a local non-governmental organization in Odisha, India, to develop an approach that provides household-level piped water connections contingent on full community-level toilet coverage. METHODS This matched cohort study was designed to assess the effectiveness of a combined piped water and sanitation intervention. Households with children <5 years in 45 randomly selected intervention villages and 45 matched control villages will be followed over 17 months. The primary outcome is prevalence of diarrhoeal diseases; secondary health outcomes include soil-transmitted helminth infection, nutritional status, seroconversion to enteric pathogens, urogenital infections and environmental enteric dysfunction. In addition, intervention effects on sanitation and water coverage, access and use, environmental fecal contamination, women's empowerment, as well as collective efficacy, and intervention cost and cost-effectiveness will be assessed. ETHICS AND DISSEMINATION The study protocol has been reviewed and approved by the ethics boards of the London School of Hygiene and Tropical Medicine, UK and KIIT University, Bhubaneswar, India. Findings will be disseminated via peer-reviewed literature and presentation to stakeholders, government officials, implementers and researchers. TRIAL REGISTRATION NUMBER NCT02441699.
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Affiliation(s)
- Heather Reese
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | | | - Belen Torondel
- London School of Hygiene and Tropical Medicine, London, UK
| | - Gloria Sclar
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Maryann G Delea
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- London School of Hygiene and Tropical Medicine, London, UK
| | - Sheela S Sinharoy
- Nutrition and Health Sciences Program, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Laura Zambrano
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Bethany Caruso
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Samir R Mishra
- School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India
| | - Howard H Chang
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Thomas Clasen
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- London School of Hygiene and Tropical Medicine, London, UK
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Spatial and Temporal Spread of Acute Viral Respiratory Infections in Young Children Living in High-altitude Rural Communities: A Prospective Household-based Study. Pediatr Infect Dis J 2016; 35:1057-61. [PMID: 27404599 PMCID: PMC5021582 DOI: 10.1097/inf.0000000000001234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Few studies have described patterns of transmission of viral acute respiratory infections (ARI) in children in developing countries. We examined the spatial and temporal spread of viral ARI among young children in rural Peruvian highland communities. Previous studies have described intense social interactions in those communities, which could influence the transmission of viral infections. METHODS We enrolled and followed children <3 years of age for detection of ARI during the 2009 to 2011 respiratory seasons in a rural setting with relatively wide geographic dispersion of households and communities. Viruses detected included influenza, respiratory syncytial virus (RSV), human metapneumovirus and parainfluenza 2 and 3 viruses (PIV2, PIV3). We used geospatial analyses to identify specific viral infection hot spots with high ARI incidence. We also explored the local spread of ARI from index cases using standard deviational ellipses. RESULTS Geospatial analyses revealed hot spots of high ARI incidence around the index cases of influenza outbreaks and RSV outbreak in 2010. Although PIV3 in 2009 and PIV2 in 2010 showed distinct spatial hot spots, clustering was not in proximity to their respective index cases. No significant aggregation around index cases was noted for other viruses. Standard deviational ellipse analyses suggested that influenza B and RSV in 2010, and human metapneumovirus in 2011 spread temporally in alignment with the major road network. CONCLUSIONS Despite the geographic dispersion of communities in this rural setting, we observed a rapid spread of viral ARI among young children. Influenza strains and RSV in 2010 had distinctive outbreaks arising from their index cases.
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Howard LM, Johnson M, Gil AI, Griffin MR, Edwards KM, Lanata CF, Williams JV, Grijalva CG. Molecular Epidemiology of Rhinovirus Detections in Young Children. Open Forum Infect Dis 2016; 3:ofw001. [PMID: 26900577 PMCID: PMC4759584 DOI: 10.1093/ofid/ofw001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/01/2016] [Indexed: 02/06/2023] Open
Abstract
Background. Human rhinoviruses (HRVs) are frequently detected in children with acute respiratory illnesses (ARIs) but also in asymptomatic children. We compared features of ARI with HRV species (A, B, C) and determined genotypes associated with repeated HRV detections within individuals. Methods. We used clinical data and respiratory samples obtained from children <3 years old during weekly active household-based surveillance. A random subset of samples in which HRV was detected from individuals during both ARI and an asymptomatic period within 120 days of the ARI were genotyped. Features of ARI were compared among HRV species. Concordance of genotype among repeated HRV detections within individuals was assessed. Results. Among 207 ARI samples sequenced, HRV-A, HRV-B, and HRV-C were detected in 104 (50%), 20 (10%), and 83 (40%), respectively. Presence of fever, decreased appetite, and malaise were significantly higher in children with HRV-B. When codetections with other viruses were excluded (n = 155), these trends persisted, but some did not reach statistical significance. When 58 paired sequential HRV detections during asymptomatic and ARI episodes were sequenced, only 9 (16%) were identical genotypes of HRV. Conclusions. Clinical features may differ among HRV species. Repeated HRV detections in young children frequently represented acquisition of new HRV strains.
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Affiliation(s)
- Leigh M Howard
- Division of Infectious Diseases, Department of Pediatrics; Vanderbilt Vaccine Research Program, Nashville, Tennessee
| | - Monika Johnson
- Department of Pediatrics , University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center , Pennsylvania
| | - Ana I Gil
- Instituto de Investigacion Nutricional , Lima , Peru
| | - Marie R Griffin
- Department of Health Policy , Vanderbilt University, Tennessee
| | - Kathryn M Edwards
- Division of Infectious Diseases, Department of Pediatrics; Vanderbilt Vaccine Research Program, Nashville, Tennessee
| | - Claudio F Lanata
- Division of Infectious Diseases, Department of Pediatrics; Instituto de Investigacion Nutricional, Lima, Peru
| | - John V Williams
- Department of Pediatrics , University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center , Pennsylvania
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Abstract
BACKGROUND Viruses are commonly detected in children with acute respiratory illnesses (ARIs) and in asymptomatic children. Longitudinal studies of viral detections during asymptomatic periods surrounding ARI could facilitate interpretation of viral detections but are currently scant. METHODS We used reverse transcription polymerase chain reaction to analyze respiratory samples from young Andean children for viruses during asymptomatic periods within 8-120 days of index ARI (cough or fever). We compared viral detections over time within children and explored reverse transcription polymerase chain reaction cycle thresholds (CTs) as surrogates for viral loads. RESULTS At least 1 respiratory virus was detected in 367 (43%) of 859 samples collected during asymptomatic periods, with more frequent detections in periods with rhinorrhea (49%) than those without (34%, P < 0.001). Relative to index ARI with human rhinovirus (HRV), adenovirus (AdV), respiratory syncytial virus (RSV) and parainfluenza virus detected, the same viruses were also detected during 32, 22, 10 and 3% of asymptomatic periods, respectively. RSV was only detected 8-30 days after index RSV ARI, whereas HRV and AdV were detected throughout asymptomatic periods. Human metapneumovirus and influenza were rarely detected during asymptomatic periods (<3%). No significant differences were observed in the CT for HRV or AdV during asymptomatic periods relative to ARI. For RSV, CTs were significantly lower during ARI relative to the asymptomatic period (P = 0.03). CONCLUSIONS These findings indicate that influenza, human metapneumovirus, parainfluenza virus and RSV detections in children with an ARI usually indicate a causal relationship. When HRV or AdV is detected during ARI, the causal relationship is less certain.
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del Valle Mendoza J, Cornejo-Tapia A, Weilg P, Verne E, Nazario-Fuertes R, Ugarte C, del Valle LJ, Pumarola T. Incidence of respiratory viruses in Peruvian children with acute respiratory infections. J Med Virol 2015; 87:917-24. [PMID: 25784285 PMCID: PMC7167149 DOI: 10.1002/jmv.24159] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2015] [Indexed: 11/08/2022]
Abstract
Acute respiratory infections are responsible for high morbi-mortality in Peruvian children. However, the etiological agents are poorly identified. This study, conducted during the pandemic outbreak of H1N1 influenza in 2009, aims to determine the main etiological agents responsible for acute respiratory infections in children from Lima, Peru. Nasopharyngeal swabs collected from 717 children with acute respiratory infections between January 2009 and December 2010 were analyzed by multiplex RT-PCR for 13 respiratory viruses: influenza A, B, and C virus; parainfluenza virus (PIV) 1, 2, 3, and 4; and human respiratory syncytial virus (RSV) A and B, among others. Samples were also tested with direct fluorescent-antibodies (DFA) for six respiratory viruses. RT-PCR and DFA detected respiratory viruses in 240 (33.5%) and 85 (11.9%) cases, respectively. The most common etiological agents were RSV-A (15.3%), followed by influenza A (4.6%), PIV-1 (3.6%), and PIV-2 (1.8%). The viruses identified by DFA corresponded to RSV (5.9%) and influenza A (1.8%). Therefore, respiratory syncytial viruses (RSV) were found to be the most common etiology of acute respiratory infections. The authors suggest that active surveillance be conducted to identify the causative agents and improve clinical management, especially in the context of possible circulation of pandemic viruses.
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Affiliation(s)
- Juana del Valle Mendoza
- School of Medicine, Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas-UPC, Lima, Perú; Nutrition Research Institute, Lima, Perú
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13
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Grijalva CG, Goeyvaerts N, Verastegui H, Edwards KM, Gil AI, Lanata CF, Hens N. A household-based study of contact networks relevant for the spread of infectious diseases in the highlands of Peru. PLoS One 2015; 10:e0118457. [PMID: 25734772 PMCID: PMC4348542 DOI: 10.1371/journal.pone.0118457] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/06/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Few studies have quantified social mixing in remote rural areas of developing countries, where the burden of infectious diseases is usually the highest. Understanding social mixing patterns in those settings is crucial to inform the implementation of strategies for disease prevention and control. We characterized contact and social mixing patterns in rural communities of the Peruvian highlands. METHODS AND FINDINGS This cross-sectional study was nested in a large prospective household-based study of respiratory infections conducted in the province of San Marcos, Cajamarca-Peru. Members of study households were interviewed using a structured questionnaire of social contacts (conversation or physical interaction) experienced during the last 24 hours. We identified 9015 reported contacts from 588 study household members. The median age of respondents was 17 years (interquartile range [IQR] 4-34 years). The median number of reported contacts was 12 (IQR 8-20) whereas the median number of physical (i.e. skin-to-skin) contacts was 8.5 (IQR 5-14). Study participants had contacts mostly with people of similar age, and with their offspring or parents. The number of reported contacts was mainly determined by the participants' age, household size and occupation. School-aged children had more contacts than other age groups. Within-household reciprocity of contacts reporting declined with household size (range 70%-100%). Ninety percent of household contact networks were complete, and furthermore, household members' contacts with non-household members showed significant overlap (range 33%-86%), indicating a high degree of contact clustering. A two-level mixing epidemic model was simulated to compare within-household mixing based on observed contact networks and within-household random mixing. No differences in the size or duration of the simulated epidemics were revealed. CONCLUSION This study of rural low-density communities in the highlands of Peru suggests contact patterns are highly assortative. Study findings support the use of within-household homogenous mixing assumptions for epidemic modeling in this setting.
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Affiliation(s)
- Carlos G. Grijalva
- Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- * E-mail:
| | - Nele Goeyvaerts
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium
- Centre for Health Economics Research and Modeling Infectious Diseases, and Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Wilrijk, Belgium
| | | | - Kathryn M. Edwards
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Ana I. Gil
- Instituto de Investigación Nutricional, Lima, Peru
| | | | - Niel Hens
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium
- Centre for Health Economics Research and Modeling Infectious Diseases, and Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Wilrijk, Belgium
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