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Paul K, Elphingstone JW, Williams M, Manfredi JN, Jardaly A, Schick S, Floyd S, Brabston EW, Momaya AM, Ponce BA. Suspensory fixation for bone transfer procedures in shoulder instability is superior to screws in an angled construct: a biomechanical analysis. JSES Int 2024; 8:250-256. [PMID: 38464447 PMCID: PMC10920126 DOI: 10.1016/j.jseint.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
Background The Latarjet procedure is a common bony augmentation procedure for anterior shoulder instability. Historically, screw fixation is used to secure the coracoid graft to the anterior glenoid surface; however, malpositioning of the graft leads to oblique screw insertion that contributes to complications. Suture buttons (SBs) are a more recent fixation technique that have not been studied alongside standard screw fixation in the context of biomechanical models of angulated fixation. This study aims to compare the biomechanical strength of single and double, screw and SB fixation at various levels of angulation. Methods Testing was performed using polyurethane models from Sawbones. The graft piece was secured with screw fixation (Arthrex, Naples, FL, USA) or suspensory button (ABS Tightrope, Arthrex, Naples, FL, USA). Single or double constructs of screws and SBs were affixed at 0°, 15°, and 30° angles to the face of the glenoid component. An aluminum testing jig held the samples securely while a materials testing system applied loads. Five constructs were used for each condition and assessed load to failure testing. Results For single fixation constructs, suspensory buttons were 60% stronger than screws at 0° (P < .001), and 52% stronger at 15° (P = .004); however, at 30°, both were comparable (P = .180). Interestingly, single suspensory button at 15° was equivalent to a single screw at 0° (P = .310). For double fixation, suspensory buttons (DT) were 32% stronger than screws at 0° (P < .001) and 35% stronger than screws at 15° (P < .001). Both double fixation methods were comparable at 30° (P = .061). Suspensory buttons at 15° and 30° were equivalent to double screws at 0 (P = .280) and 15° (P = .772), respectively. Conclusion These measurements indicate that the suspensory button has a significantly higher load to failure capacity over the screw fixation technique, perpendicularly and with up to 15° of angulation. These analyses also indicate that the suspensory button fixation offers superior strength even when positioned more obliquely than the screw fixation. Therefore, suspensory button fixation may confer more strength while offering greater margin for error when positioning the graft.
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Affiliation(s)
- Kyle Paul
- Department of Orthopedic Surgery, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Joseph W. Elphingstone
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Marshall Williams
- Department of Orthopedic Surgery, The Hughston Clinic, Columbus, GA, USA
| | - John N. Manfredi
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Achraf Jardaly
- Department of Orthopedic Surgery, The Hughston Clinic, Columbus, GA, USA
| | - Samuel Schick
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Susan Floyd
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Eugene W. Brabston
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amit M. Momaya
- Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Ponce
- Department of Orthopedic Surgery, The Hughston Clinic, Columbus, GA, USA
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Hixson H, McCullough S, Haywood S, Shoemaker C, Donohue L, Floyd S, Anderson R, Mannem H. Tolerability of Posaconazole as Fungal Prophylaxis in Lung Transplant Patients Compared to Voriconazole. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.1374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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Shanaube K, Schaap A, Klinkenberg E, Floyd S, Bwalya J, Cheeba M, de Haas P, Kosloff B, Ruperez M, Hayes R, Ayles H. SARS-CoV-2 seroprevalence and associated risk factors in periurban Zambia: a population-based study. Int J Infect Dis 2022; 118:256-263. [PMID: 35306205 PMCID: PMC8925090 DOI: 10.1016/j.ijid.2022.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/10/2022] [Accepted: 03/12/2022] [Indexed: 10/29/2022] Open
Abstract
BACKGROUND We nested a seroprevalence survey within the TREATS (Tuberculosis Reduction through Expanded Antiretroviral Treatment and Screening) project. We aimed to measure the seroprevalence of SARS-CoV-2 infection and investigate associated risk factors in one community (population ∼27,000) with high prevalence of TB/HIV in Zambia. METHODS The study design was cross-sectional. A random sample of 3592 individuals aged ≥15 years enrolled in the TREATS TB-prevalence survey were selected for antibody testing. Randomly selected blocks of residence were visited between October 2020 and March 2021. Antibodies against SARS-CoV-2 were detected using Abbott- ARCHITECT SARS-CoV-2 IgG assay. RESULTS A total of 3035/3526 (86.1%) individuals had a blood sample taken. Antibody testing results were available for 2917/3035 (96.1%) participants. Overall, 401/2977 (13.5%) individuals tested positive for IgG antibodies. Seroprevalence was similar by sex (12.7% men vs 14.0% women) and was lowest in the youngest age group 15-19 years (9.7%) and similar in ages 20 years and older (∼15%). We found no evidence of an association between seroprevalence and HIV-status or TB. There was strong evidence (p <0.001) of variation by time of enrollment, with prevalence varying from 2.8% (95% CI 0.8-4.9) among those recruited in December 2020 to 33.7% (95% CI 27.7-39.7) among those recruited in mid-February 2021. CONCLUSION Seroprevalence was 13.5% but there was substantial variation over time, with a sharp increase to approximately 35% toward the end of the second epidemic wave.
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Affiliation(s)
| | - A Schaap
- Zambart, Lusaka, Zambia; London School of Hygiene and Tropical Medicine
| | | | - S Floyd
- London School of Hygiene and Tropical Medicine
| | | | | | - P de Haas
- KNCV Tuberculosis Foundation, Netherlands
| | - B Kosloff
- Zambart, Lusaka, Zambia; London School of Hygiene and Tropical Medicine
| | - M Ruperez
- London School of Hygiene and Tropical Medicine
| | - R Hayes
- London School of Hygiene and Tropical Medicine
| | - H Ayles
- Zambart, Lusaka, Zambia; London School of Hygiene and Tropical Medicine
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Sabapathy K, Stöckl H, Mulubwa C, Mubekapi-Musadaidzwa C, Hoddinott G, Floyd S, Seeley J, Bond V, Bock P, Fidler S, Ayles H, Hayes R. Intimate Partner Violence (IPV) and Associated Factors in HPTN 071 (PopART) Study Communities in Zambia and South Africa-A Comparison by HIV Status. AIDS Behav 2022; 26:1355-1365. [PMID: 35165795 PMCID: PMC9001629 DOI: 10.1007/s10461-021-03492-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2021] [Indexed: 11/17/2022]
Abstract
The HPTN 071(PopART) study was a community-randomised trial in Zambia and South Africa, examining the impact of combination-prevention including universal testing and treatment (UTT), on HIV-incidence. This sub-study evaluated factors associated with IPV (physical and/or sexual) to identify differences by HIV status. During 2015-16, a random subset of adults who participated in the first year of the PopART intervention were recruited and standardised questionnaires were administered. Logistic regression was performed to estimate odds ratios of factors associated with IPV. Among > 700 women studied (300 HIV-negative;400 HIV-positive), ~ 20% reported experiencing physical and/or sexual violence in the last 12-months. Sexual violence was similar by HIV status, but physical violence and reporting both physical/sexual violence was more common among HIV-positive women. Spending nights away from the community in the last 12-months was associated with higher odds of IPV among both HIV-negative (aOR 3.17, 95% CI 1.02-9.81) and HIV-positive women (aOR 1.79, 95% CI 0.99-3.24). Among HIV-positive women, financial autonomy was associated with reduced IPV (aOR:0.41,95%CI:0.23-0.75) while pregnancy in the last 12-months (aOR 2.25, 95% CI 1.07-4.74), risk of alcohol dependence (aOR 2.75, 95% CI 1.51-5.00) and risk of mental distress (aOR 2.62, 95% CI 1.33-5.16) were associated with increased IPV. Among HIV-negative women reporting sex in the last 12-months, transactional sex (aOR 3.97, 95% CI 1.02-15.37) and not knowing partner's HIV status (aOR 3.01, 95% CI 1.24-7.29) were associated with IPV. IPV was commonly reported in the study population and factors associated with IPV differed by HIV status. The association of mobility with IPV warrants further research. The high prevalence of harmful alcohol use and mental distress, and their association with IPV among HIV-positive women require urgent attention.
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Affiliation(s)
- K. Sabapathy
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - H. Stöckl
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Ludwig-Maximilians-University, Munich, Germany
| | - C. Mulubwa
- Zambia AIDS Related TB Project, University of Zambia, Lusaka, Zambia
| | | | - G. Hoddinott
- Desmond Tutu TB Centre, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | - S. Floyd
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - J. Seeley
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - V. Bond
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Zambia AIDS Related TB Project, University of Zambia, Lusaka, Zambia
| | - P. Bock
- Desmond Tutu TB Centre, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | | | - H. Ayles
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Zambia AIDS Related TB Project, University of Zambia, Lusaka, Zambia
| | - R. Hayes
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - on behalf of HPTN 071 (PopART) Study Team
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Ludwig-Maximilians-University, Munich, Germany
- Zambia AIDS Related TB Project, University of Zambia, Lusaka, Zambia
- Desmond Tutu TB Centre, Stellenbosch University, Stellenbosch, Western Cape South Africa
- Imperial College London, London, UK
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Holden R, Park J, Price A, Floyd S, Oldham M. Evaluation of a method to measure fluorescent cell burden in complex culture systems. Biomed Phys Eng Express 2022; 8. [PMID: 35417904 DOI: 10.1088/2057-1976/ac6701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/13/2022] [Indexed: 11/11/2022]
Abstract
Purpose. This work introduces and evaluates a method for accurate in-vitro measurement of fluorescent cell burden in complex 3D-culture conditions.Methods.The Fluorescent Cell Burden (FCB) method was developed to analyze the burden of 4T1 mCherry-expressing cells grown in an organotypic co-culture model of brain metastasis using 400μm rat brain slices. As a first step, representative simulated image-data accurately reflecting the 4T1 experimental data, but with known ground truth burden, were created. The FCB method was then developed in the CellProfiler software to measure the integrated intensity and area of the colonies in the simulated image data. Parameters in the pipeline were varied to span the experimentally observed range (e.g. of cell colony size) and the result compared with simulation ground truth to evaluate and optimize FCB performance. The optimized CellProfiler pipeline was then applied to the original 4T1 tumor cell images to determine colony growth with time, and re-applied with upper and lower bound parameters to determine uncertainty estimates.Results.The FCB method measured integrated intensity across 10 simulated images with an accuracy of 99.23% ± 0.75%. When colony density was increased by increasing colony number to 450, 600, and 750, the FCB measurement was 98.68%, 100.9%, 97.6% and 113.5% of the true value respectively. For the increasing number of cells plated on the rat brain slices, the integrated intensity increased nearly linearly with cell count except for at high cell counts, where it is hypothesized that shadowing from clumped cells causes a sub-linear relationship.Conclusion. The FCB method accurately measured an integrated fluorescent light intensity to within 5% of ground truth for a wide range of simulated image data spanning the range of observed variability in experimental data. The method is readily customizable to in-vitro studies requiring estimation of fluorescent tumor cell burden.
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Affiliation(s)
- R Holden
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - J Park
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - A Price
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - S Floyd
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - M Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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Hensen B, Phiri M, Schaap A, Sigande L, Simwinga M, Floyd S, Belemu S, Simuyaba M, Shanaube K, Fidler S, Hayes R, Ayles HM. Uptake of HIV Testing Services Through Novel Community-Based Sexual and Reproductive Health Services: An Analysis of the Pilot Implementation Phase of the Yathu Yathu Intervention for Adolescents and Young People Aged 15-24 in Lusaka, Zambia. AIDS Behav 2022; 26:172-182. [PMID: 34302282 DOI: 10.1007/s10461-021-03368-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2021] [Indexed: 11/24/2022]
Abstract
Adolescents and young people aged 15-24 are underserved by available HIV-testing services (HTS). Delivering HTS through community-based, peer-led, hubs may prove acceptable and accessible to adolescents and young people, thus increasing HIV-testing coverage. We used data from the pilot phase of a cluster-randomised trial of community-based sexual and reproductive health services for adolescents and young people in Lusaka, Zambia, between September 2019 and January 2020, to explore factors associated with uptake of HTS through community-based hubs. 5,757 adolescents and young people attended the hubs (63% female), among whom 75% tested for HIV (76% of females, 75% of males). Community-based hubs provided HTS to 80% of adolescents and young people with no history of HIV-testing. Among females, uptake of HTS was lower among married/cohabiting females; among males, uptake was lower among unmarried males and among individuals at risk of hazardous alcohol use. The high number of adolescents and young people accessing hubs for HIV testing suggests they are acceptable. Enhanced targeting of HTS to groups who may not perceive their HIV risk needs to be implemented.
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Affiliation(s)
- B Hensen
- Faculty of Infectious and Tropical Diseases, Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK.
| | | | - A Schaap
- Zambart, Lusaka, Zambia
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | | | | | - S Floyd
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | | | | | | | - S Fidler
- Imperial College London, Imperial College National Institute of Heath Research BRC, London, UK
| | - R Hayes
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - H M Ayles
- Faculty of Infectious and Tropical Diseases, Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
- Zambart, Lusaka, Zambia
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Bell-Mandla NF, Sloot R, Maarman G, Griffith S, Moore A, Floyd S, Hayes R, Fidler S, Ayles H, Bock P. Improving retention of community-recruited participants in HIV prevention research through Saturday household visits; findings from the HPTN 071 (PopART) study in South Africa. BMC Med Res Methodol 2021; 21:242. [PMID: 34749654 PMCID: PMC8574030 DOI: 10.1186/s12874-021-01415-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 09/28/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Identifying successful strategies to improve participant retention in longitudinal studies remains a challenge. In this study we evaluated whether non-traditional fieldworker shifts (after hours during the week and weekends) enhanced participant retention when compared to retention during traditional weekday shifts in the HPTN 071 (PopART) population cohort (PC). METHODS HPTN 071 (PopART) PC participants were recruited and followed up in their homes on an annual basis by research fieldworkers over a 3-4 year period. The average number of successful follow-up visits, where a PC participant was found and retained in the study, was calculated for each of 3 visit schedules (early weekday shift, late weekday shift, and Saturday shift), and standardized to account for variation in fieldwork shift duration. We used one-way univariate analysis of variance (ANOVA) to describe differences in mean-successful visits and 95% confidence intervals between the shift types. RESULTS Data on 16 651 successful visits were included. Successful visit rates were higher when conducting Saturday visits (14.0; 95% CI: 11.3-16.6) compared to both regular (4.5; 95% CI: 3.7-5.3) and late weekday shifts (5.3; 95% CI: 4.7-5.8) overall and in all subgroup analyses (P<0.001). The successful visit rate was higher amongst women than men were during all shift types (3.2 vs. 1.3, p<0.001). Successful visit rates by shift type did not differ significantly by age, over time, by PC round or by community triplet. CONCLUSION The number of people living with HIV continues to increase annually. High quality evidence from longitudinal studies remains critical for evaluating HIV prevention and treatment strategies. This study showed a significant benefit on participant retention through introduction of Saturday shifts for home visits and these data can make an important contribution to the emerging body of evidence for improving retention in longitudinal research. TRIAL REGISTRATION PopART was approved by the Stellenbosch University Health Research Ethics Committees (N12/11/074), London School of Hygiene and Tropical Medicine (6326) ethics committee and the Division of AIDS (DAIDS) (Protocol ID 11865). PopART was registered with ClinicalTrials.gov (registration number NCT01900977 ).
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Affiliation(s)
- N. F. Bell-Mandla
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - R. Sloot
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - G. Maarman
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | | | | | - S. Floyd
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - R. Hayes
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - S. Fidler
- Department of Medicine, Imperial College London, St Mary’s Campus, London, UK
| | - H. Ayles
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Zambart, Lusaka, Zambia
| | - P. Bock
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - on behalf of the HPTN 071 (PopART) study team
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- FHI 360, Durham, NC USA
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
- Department of Medicine, Imperial College London, St Mary’s Campus, London, UK
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Zambart, Lusaka, Zambia
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Hensen B, Phiri M, Schaap A, Floyd S, Simuyaba M, Mwenge L, Sigande L, Belemu S, Shanaube K, Simwinga M, Fidler S, Hayes R, Ayles H. Yathu Yathu ("For us, by us"): Design of a cluster-randomised trial of the impact of community-based, peer-led comprehensive sexual and reproductive health services for adolescents and young people aged 15 to 24 in Lusaka, Zambia. Contemp Clin Trials 2021; 110:106568. [PMID: 34543725 DOI: 10.1016/j.cct.2021.106568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/16/2021] [Accepted: 09/13/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND In sub-Saharan Africa, the growing population of adolescents and young people aged 15 to 24 face a high burden of HIV, and other preventable and treatable sexually transmitted infections. Despite this burden, adolescents and young people are the population least served by available sexual and reproductive (SRH) services. This trial aims to evaluate the impact of community-based peer-led SRH services, combined with a novel incentivised "loyalty card" system, on knowledge of HIV status and coverage of SRH services. METHODS A cluster-randomised trial (CRT) with embedded process and economic evaluation. DISCUSSION With little available evidence of the impact of community-based, peer-led services on coverage of SRH services, our study will provide evidence critical to expanding our knowledge of how to reach adolescents and young people. The "loyalty card" system is also a novel approach to providing SRH services. The delivery of community-based services supported by incentives in the form of loyalty cards is innovative, and may prove a simple strategy to improve access to SRH services. Adolescents and young people remain underserved by available SRH services; there remains a critical need to identify ways to provide adolescents and young people with access to SRH services. Rigorous evidence of whether this innovative strategy, with strong links to the local health facility, increases coverage of critical SRH services would add to the evidence-base of how to reach adolescents and young people.
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Affiliation(s)
- B Hensen
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom.
| | | | - A Schaap
- Zambart, Lusaka, Zambia; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - S Floyd
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | | | | | | | | | - S Fidler
- Imperial College and Imperial College NIHR BRC, London, United Kingdom
| | - R Hayes
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - H Ayles
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom; Zambart, Lusaka, Zambia
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Hensen B, Machingura F, Busza J, Birdthistle I, Chabata S, Chiyaka T, Floyd S, Jamali G, Mushati P, Hargreaves J, Cowan F. How Can We Support the Use of Oral PrEP Among Young Women who Sell Sex? A PrEP Cascade Analysis. J Acquir Immune Defic Syndr 2021; 88:45-56. [PMID: 34050101 PMCID: PMC8357043 DOI: 10.1097/qai.0000000000002733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/19/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND We constructed self-reported pre-exposure prophylaxis (PrEP) cascades and explored factors associated with and barriers to PrEP use to inform efforts to support PrEP use among young women who sell sex. METHODS Using self-reported data from HIV-negative young women who sell sex enrolled into a cohort study using respondent-driven sampling in Zimbabwe, we constructed PrEP cascades assessing knowledge of, ever offered, ever used, and current PrEP use in 2017 and 2019. We used logistic regression to examine factors associated with PrEP use by 2019. Through qualitative interviews with 43 women enrolled in the cohort, we investigated barriers to PrEP use. RESULTS At enrollment, 50% of women had heard of PrEP, 12% had ever been offered PrEP, and 7% ever used PrEP. Over time, all cascade domains: 96% of women had heard of and 55% reported an active offer of PrEP. Among women retained in the study in 2019 (56%; n = 538), 34% ever took PrEP by 2019. PrEP use was associated with, at enrollment, reporting more clients in the past month (10+: 45% vs 1-3: 27% adjOR = 1.71 95% CI: 1.06 to 2.76), duration of selling sex (24% <2 years vs 38% 2-3 years; adjOR = 0.51 95% CI: 0.32 to 0.83), and having visited a female sex worker program in the past 12 months (55% vs 27%; adjOR = 2.92 95% CI: 1.91 to 4.46). Qualitative interviews revealed fear of disclosing sex work, HIV-related/ART-related stigma, and (opportunity) costs of accessing PrEP as barriers to use. CONCLUSION PrEP use was associated with factors known to increase HIV risk. Fear of stigma, disclosure, and supply-side barriers need to be addressed to increase women's ability to use PrEP.
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Affiliation(s)
- B. Hensen
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom;
| | - F. Machingura
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
| | - J. Busza
- Centre for Evaluation, London School of Hygiene and Tropical Medicine, London, United Kingdom;
| | - I. Birdthistle
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom; and
| | - S.T. Chabata
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
| | - T. Chiyaka
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
| | - S. Floyd
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom; and
| | - G. Jamali
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
| | - P. Mushati
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
| | - J. Hargreaves
- Centre for Evaluation, London School of Hygiene and Tropical Medicine, London, United Kingdom;
| | - F.M. Cowan
- Centre for Sexual Health and HIV/AIDS Research (CeSHHAR) Zimbabwe, Harare, Zimbabwe;
- Faculty of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
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Viljoen L, Mainga T, Casper R, Mubekapi-Musadaidzwa C, Wademan DT, Bond VA, Pliakas T, Bwalya C, Stangl A, Phiri M, Yang B, Shanaube K, Bock P, Fidler S, Hayes R, Ayles H, Hargreaves JR, Hoddinott G, Seeley J, Donnell D, Floyd S, Mandla N, Bwalya J, Sabapathy K, Eshleman SH, Macleod D, Moore A, Vermund SH, Hauck K, Shanaube K. Community-based health workers implementing universal access to HIV testing and treatment: lessons from South Africa and Zambia-HPTN 071 (PopART). Health Policy Plan 2021; 36:881-890. [PMID: 33963387 PMCID: PMC8227454 DOI: 10.1093/heapol/czab019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2021] [Indexed: 01/20/2023] Open
Abstract
The global expansion of HIV testing, prevention and treatment services is necessary to achieve HIV epidemic control and promote individual and population health benefits for people living with HIV (PLHIV) in sub-Saharan Africa. Community-based health workers (CHWs) could play a key role in supporting implementation at scale. In the HPTN 071 (PopART) trial in Zambia and South Africa, a cadre of 737 study-specific CHWs, working closely with government-employed CHW, were deployed to deliver a ‘universal’ door-to-door HIV prevention package, including an annual offer of HIV testing and referral services for all households in 14 study communities. We conducted a process evaluation using qualitative and quantitative data collected during the trial (2013–2018) to document the implementation of the CHW intervention in practice. We focused on the recruitment, retention, training and support of CHWs, as they delivered study-specific services. We then used these descriptions to: (i) analyse the fidelity to design of the delivery of the intervention package, and (ii) suggest key insights for the transferability of the intervention to other settings. The data included baseline quantitative data collected with the study-specific CHWs (2014–2018); and qualitative data from key informant interviews with study management (n = 91), observations of CHW training events (n = 12) and annual observations of and group discussions (GD) with intervention staff (n = 68). We show that it was feasible for newly recruited CHWs to implement the PopART intervention with good fidelity, supporting the interpretation of the trial outcome findings. This was despite some challenges in managing service quality and CHW retention in the early years of the programme. We suggest that by prioritizing the adoption of key elements of the in-home HIV services delivery intervention model—including training, emotional support to workers, monitoring and appropriate remuneration for CHWs—these services could be successfully transferred to new settings.
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Affiliation(s)
- Lario Viljoen
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa.,Department of Sociology and Social Anthropology, Stellenbosch University, Stellenbosch, South Africa
| | - Tila Mainga
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia
| | - Rozanne Casper
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
| | - Constance Mubekapi-Musadaidzwa
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
| | - Dillon T Wademan
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
| | - Virginia A Bond
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia.,Global Health and Development Department, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Triantafyllos Pliakas
- Department of Public Health, Environments and Society, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Chiti Bwalya
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia
| | - Anne Stangl
- International Center for Research on Women, Washington, DC, USA.,Hera Solutions, Baltimore, MD, USA
| | - Mwelwa Phiri
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia
| | - Blia Yang
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
| | - Kwame Shanaube
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia
| | - Peter Bock
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
| | - Sarah Fidler
- Department of Infectious Disease, Imperial College NIHR BRC, Imperial College London, UK
| | - Richard Hayes
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Helen Ayles
- Zambart, School of Public Health, Ridgeway Campus, University of Zambia, Lusaka, Zambia.,Department of Public Health, Environments and Society, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - James R Hargreaves
- Department of Public Health, Environments and Society, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Graeme Hoddinott
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Desmond Tutu TB Centre, Stellenbosch University, Lower Level Clinical Building, Francie van Zijl Drive, Cape Town 7505, South Africa
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11
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Jacobs C, Barbour A, Suneja G, Williamson H, Floyd S, Torok J, Kirkpatrick J. Whole Brain Radiotherapy Practice Patterns in the Era of Stereotactic Radiosurgery. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.1249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bock P, Nel K, Fatti G, Sloot R, Ford N, Voget J, Gunst C, Grobbelaar N, Louis F, Floyd S, Hayes R, Ayles H, Beyers N, Fidler S. Renal dysfunction by baseline CD4 cell count in a cohort of adults starting antiretroviral treatment regardless of CD4 count in the HIV Prevention Trials Network 071 [HPTN 071; Population Effect of Antiretroviral Therapy to Reduce HIV Transmission (PopART)] study in South Africa. HIV Med 2019; 20:392-403. [PMID: 30963667 PMCID: PMC6767782 DOI: 10.1111/hiv.12729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2019] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Renal dysfunction is a significant cause of morbidity and mortality among HIV-positive individuals. This study evaluated renal dysfunction in a cohort of adults who started antiretroviral treatment (ART) regardless of CD4 count at three Department of Health (DOH) clinics included in the HIV Prevention Trials Network 071 (HPTN 071) Population Effect of Antiretroviral Therapy to Reduce HIV Transmission (PopART) trial. METHODS A retrospective cohort analysis of routine data for HIV-positive individuals starting ART between January 2014 and November 2015 was completed. Incident renal dysfunction was defined as an estimated glomerular filtration rate (eEGFR) < 60 mL/min after ART initiation among individuals with a baseline (pre-ART) eGFR ≥ 60 mL/min. RESULTS Overall, 2423 individuals, with a median baseline CD4 count of 328 cells/μL [interquartile range (IQR) 195-468 cells/μL], were included in the analysis. Forty-seven individuals had a baseline eGFR < 60 mL/min. Among 1634 nonpregnant individuals started on a tenofovir-containing ART regimen and with a baseline eGFR ≥ 60 mL/min, 27 developed an eGFR < 60 mL/min on ART. Regression analysis showed lower odds of baseline eGFR < 60 mL/min at baseline CD4 counts of > 500 cells/μL [adjusted odds ratio (aOR) 0.29; 95% confidence interval (CI) 0.11-0.80], 351-500 cells/μL (aOR 0.22; 95% CI 0.08-0.59) and 201-350 (aOR 0.48; 95% CI: 0.24-0.97) compared with baseline CD4 counts < 200 cells/μL. CONCLUSIONS This study showed low rates of renal dysfunction at baseline and on ART, with lower rates of baseline renal dysfunction among individuals with baseline CD4 counts > 200 cells/μL. Strategies that use baseline characteristics, such as age, to identify individuals at high risk of renal dysfunction on ART for enhanced eGFR monitoring may be effective and should be the subject of future research.
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Affiliation(s)
- P Bock
- Department of Paediatrics and Child HealthFaculty of Medicine and Health SciencesDesmond Tutu TB CentreStellenbosch UniversityCape TownSouth Africa
| | - K Nel
- Department of Paediatrics and Child HealthFaculty of Medicine and Health SciencesDesmond Tutu TB CentreStellenbosch UniversityCape TownSouth Africa
- City of Cape Town Health ServicesCape TownSouth Africa
| | - G Fatti
- Kheth’ Impilo, AIDS Free LivingCape TownSouth Africa
- Division of Epidemiology and BiostatisticsDepartment of Global HealthFaculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - R Sloot
- Department of Paediatrics and Child HealthFaculty of Medicine and Health SciencesDesmond Tutu TB CentreStellenbosch UniversityCape TownSouth Africa
- Amsterdam Institute for Global Health and DevelopmentAmsterdamThe Netherlands
| | - N Ford
- Centre for Infectious Disease Epidemiology and ResearchUniversity of Cape TownCape TownSouth Africa
| | - J Voget
- Western Cape Department of HealthHIV/AIDS, STI & TB DirectorateCape TownSouth Africa
| | - C Gunst
- Faculty of Medicine and Health SciencesStellenbosch University Division of Family Medicine and Primary Health CareStellenbosch UniversityCape TownSouth Africa
- Western Cape Department of HealthCape Winelands DistrictBrewelskloof HospitalWorcesterSouth Africa
| | | | - F Louis
- Independent ConsultantCape TownSouth Africa
| | - S Floyd
- Department of Infectious Disease EpidemiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - R Hayes
- Department of Infectious Disease EpidemiologyLondon School of Hygiene and Tropical MedicineLondonUK
| | - H Ayles
- Department of Clinical ResearchLondon School of Hygiene and Tropical MedicineLondonUK
| | - N Beyers
- Department of Paediatrics and Child HealthFaculty of Medicine and Health SciencesDesmond Tutu TB CentreStellenbosch UniversityCape TownSouth Africa
| | - S Fidler
- Department of MedicineImperial College LondonLondonUK
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13
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Bond V, Floyd S, Fenty J, Schaap A, Godfrey-Faussett P, Claassens M, Shanaube K, Ayles H, Hargreaves JR. Secondary analysis of tuberculosis stigma data from a cluster randomised trial in Zambia and South Africa (ZAMSTAR). Int J Tuberc Lung Dis 2018; 21:49-59. [PMID: 29025485 DOI: 10.5588/ijtld.16.0920] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Zambian and South African TB and HIV Reduction (ZAMSTAR) cluster-randomised trial (CRT) communities, 2006-2009. OBJECTIVES To develop TB stigma items, and evaluate changes in them in response to a household intervention aimed at reducing TB transmission and prevalence but not tailored to reduce stigma. DESIGN TB stigma was measured at baseline and 18 months later among 1826 recently diagnosed TB patients and 1235 adult members of their households across 24 communities; 12 of 24 communities were randomised to receive the household intervention. We estimated the impact of the household intervention on TB stigma using standard CRT analytical methods. RESULTS Among household members, prevalence of blame and belief in transmission myths fell in both study arms over time: adjusted prevalence ratios (aPRs) comparing the household intervention with the non-household intervention arm were respectively 0.61 (95%CI 0.26-1.44) and 0.77 (95%CI 0.48-1.25) at 18-month follow-up. Among TB patients, at baseline a low percentage experienced social exclusion and poor treatment by health staff and a relatively high percentage reported 'being made fun of', with little change over time. Disclosure of TB status increased over time in both study arms. Internalised stigma was less prevalent in the household arm at both baseline and follow-up, with an aPR of 0.85 (95%CI 0.41-1.76). Variability in stigma levels between countries and across communities was large. CONCLUSION Robust TB stigma items were developed. TB stigma was not significantly reduced by the household intervention, although confidence intervals for estimated intervention effects were wide. We suggest that stigma-specific interventions are required to effectively address TB stigma.
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Affiliation(s)
- V Bond
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK; Zambart, School of Medicine, University of Zambia, Lusaka, Zambia
| | - S Floyd
- Department of Infectious Diseases Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - J Fenty
- Department of Infectious Diseases Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - A Schaap
- Zambart, School of Medicine, University of Zambia; Lusaka, Zambia, Department of Infectious Diseases Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - P Godfrey-Faussett
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - M Claassens
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, University of Stellenbosch, Tygerberg, South Africa
| | - K Shanaube
- Zambart, School of Medicine, University of Zambia, Lusaka, Zambia
| | - H Ayles
- Zambart, School of Medicine, University of Zambia, Lusaka, Zambia; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - J R Hargreaves
- Department of Social and Environmental Health Research, Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, UK
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Sabapathy K, Mulubwa C, Mathema H, Mubekapi‐Musadaidzwa C, Schaap A, Hoddinott G, Hargreaves J, Floyd S, Ayles H, Hayes R. Is home-based HIV testing universally acceptable? Findings from a case-control study nested within the HPTN 071 (PopART) trial. Trop Med Int Health 2018; 23:678-690. [PMID: 29608231 PMCID: PMC6001569 DOI: 10.1111/tmi.13055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE The HPTN 071 (PopART) trial is examining the impact of a package including universal testing and treatment on community-level HIV incidence in Zambia and South Africa. We conducted a nested case-control study to examine factors associated with acceptance of home-based HIV testing and counselling (HB-HTC) delivered by community HIV-care providers (CHiPs) in PopART intervention communities. METHODS Of 295 447 individuals who were offered testing, random samples of individuals who declined HB-HTC (cases) and accepted HB-HTC (controls), stratified by gender and community, were selected. Odds ratios comparing cases and controls were estimated using multivariable logistic regression. RESULTS Data from 642 participants (313 cases, 329 controls) were analysed. There were no differences between cases and controls by demographic or behavioural characteristics including age, marital or socio-economic position. Participants who felt they could be open with CHiPs (AOR: 0.46, 95% CI: 0.30-0.71, P < 0.001); self-reported as not previously tested (AOR: 0.64; 95% CI: 0.43-0.95, P = 0.03); considered HTC at home to be convenient (AOR: 0.38, 95% CI: 0.27-0.54, P = 0.001); knowing others who had accepted HB-HTC from the CHiPs (AOR: 0.49, 95% CI: 0.31-0.77, P = 0.002); or were motivated to get treatment without delay (AOR: 0.60, 95% CI: 0.43-0.85, P = 0.004) were less likely to decline the offer of HB-HCT. Those who self-reported high-risk sexual behaviour were also less likely to decline HB-HCT (AOR: 0.61, 95% CI: 0.39-0.93, P = 0.02). Having stigmatising attitudes about HB-HTC was not an important barrier to HB-HCT uptake. Men who reported fear of HIV were more likely to decline HB-HCT (AOR: 2.68, 95% CI: 1.33-5.38, P = 0.005). CONCLUSION Acceptance of HB-HTC was associated with lack of previous HIV testing, positive attitudes about HIV services/treatment and perception of high sexual risk. Uptake of HB-HCT among those offered it was similar across a range of demographic and behavioural subgroups suggesting it was 'universally' acceptable.
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Affiliation(s)
- K. Sabapathy
- London School of Hygiene and Tropical MedicineLondonUK
| | - C. Mulubwa
- Zambia AIDS Related TB ProjectLusakaZambia
| | - H. Mathema
- Desmond Tutu TB CentreDepartment of Paediatric and Child HealthStellenbosch University
- Present address:
Division of Public Health Surveillance and ResponseNational Institute for Communicable DiseasesNational Health Laboratory ServiceSouth Africa
| | | | - A. Schaap
- Zambia AIDS Related TB ProjectLusakaZambia
| | - G. Hoddinott
- Desmond Tutu TB CentreDepartment of Paediatric and Child HealthStellenbosch University
| | - J. Hargreaves
- London School of Hygiene and Tropical MedicineLondonUK
| | - S. Floyd
- London School of Hygiene and Tropical MedicineLondonUK
| | - H. Ayles
- London School of Hygiene and Tropical MedicineLondonUK
- Zambia AIDS Related TB ProjectLusakaZambia
| | - R. Hayes
- London School of Hygiene and Tropical MedicineLondonUK
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Telisinghe L, Amofa-Sekyi M, Maluzi K, Kaluba-Milimo D, Cheeba-Lengwe M, Chiwele K, Kosloff B, Floyd S, Bailey SL, Ayles H. The sensitivity of the QuantiFERON ®-TB Gold Plus assay in Zambian adults with active tuberculosis. Int J Tuberc Lung Dis 2017; 21:690-696. [PMID: 28482964 PMCID: PMC5424670 DOI: 10.5588/ijtld.16.0764] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/13/2017] [Indexed: 11/24/2022] Open
Abstract
SETTING AND OBJECTIVE To investigate the sensitivity of the new interferon-gamma release assay (IGRA), QuantiFERON®-TB Gold Plus (QFT-Plus), for active TB (used as a surrogate for latent tuberculous infection) in a Zambian TB clinic. DESIGN Consecutive smear or Xpert® MTB/RIF-positive adult (age 18 years) pulmonary TB patients were recruited between June 2015 and March 2016. Venous blood was tested using QFT-Plus. The sensitivity was defined as the number positive divided by the total number tested. Using logistic regression, factors associated with positive QFT-Plus results were explored. RESULTS Of 108 patients (median age 32 years, interquartile range 27-38; 73% male; 63% human immunodeficiency virus [HIV] positive), 90 were QFT-Plus-positive, 11 were negative and seven had indeterminate results; sensitivity was 83% (95%CI 75-90). There was no difference in sensitivity by HIV status (HIV-positive 85%, 95%CI 75-93; n = 68 vs. HIV-negative 80%, 95%CI 64-91; n = 40; P = 0.59). In models adjusted for age alone, CD4 cell count <100 cells/μl (OR 0.15, 95%CI 0.02-0.96; P = 0.05) and body mass index <18.5 kg/m2 (OR 0.27, 95%CI 0.08-0.91; P = 0.02) were associated with decreased odds of positive QFT-Plus results. CONCLUSION Overall, the sensitivity of QFT-Plus is similar to that of the tuberculin skin test and other IGRAs. While overall sensitivity is not affected by HIV status, QFT-Plus sensitivity was lower among people living with HIV/acquired immune-deficiency syndrome with severe immunosuppression.
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Affiliation(s)
- L Telisinghe
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | | | - K Maluzi
- Zambart, Ridgeway Campus, Lusaka, Zambia
| | | | | | - K Chiwele
- Zambart, Ridgeway Campus, Lusaka, Zambia
| | - B Kosloff
- Zambart, Ridgeway Campus, Lusaka, Zambia, Faculty of Infectious and Tropical Diseases
| | - S Floyd
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - S-L Bailey
- Zambart, Ridgeway Campus, Lusaka, Zambia, Faculty of Infectious and Tropical Diseases
| | - H Ayles
- Zambart, Ridgeway Campus, Lusaka, Zambia, Faculty of Infectious and Tropical Diseases
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Claassens MM, van Schalkwyk C, Floyd S, Ayles H, Beyers N. Symptom screening rules to identify active pulmonary tuberculosis: Findings from the Zambian South African Tuberculosis and HIV/AIDS Reduction (ZAMSTAR) trial prevalence surveys. PLoS One 2017; 12:e0172881. [PMID: 28257424 PMCID: PMC5336223 DOI: 10.1371/journal.pone.0172881] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/11/2017] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND High tuberculosis (TB) burden countries should consider systematic screening among adults in the general population. We identified symptom screening rules to be used in addition to cough ≥2 weeks, in a context where X-ray screening is not feasible, aiming to increase the sensitivity of screening while achieving a specificity of ≥85%. METHODS We used 2010 Zambia South Africa Tuberculosis and HIV/AIDS Reduction (ZAMSTAR) survey data: a South African (SA) training dataset, a SA testing dataset for internal validation and a Zambian dataset for external validation. Regression analyses investigated relationships between symptoms or combinations of symptoms and active disease. Sensitivity and specificity were calculated for candidate rules. RESULTS Among all participants, the sensitivity of using only cough ≥2 weeks as a screening rule was less than 25% in both SA and Zambia. The addition of any three of six TB symptoms (cough <2 weeks, night sweats, weight loss, fever, chest pain, shortness of breath), or 2 or more of cough <2 weeks, night sweats, and weight loss, increased the sensitivity to ~38%, while reducing specificity from ~95% to ~85% in SA and ~97% to ~92% in Zambia. Among HIV-negative adults, findings were similar in SA, whereas in Zambia the increase in sensitivity was relatively small (15% to 22%). CONCLUSION High TB burden countries should investigate cost-effective strategies for systematic screening: one such strategy could be to use our rule in addition to cough ≥2 weeks.
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Affiliation(s)
- M. M. Claassens
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - C. van Schalkwyk
- The South African Department of Science and Technology/National Research Foundation Centre of Excellence in Epidemiological Modelling and Analysis, Stellenbosch University, Stellenbosch, South Africa
| | - S. Floyd
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - H. Ayles
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Zambia AIDS Related Tuberculosis Project, University of Zambia Ridgeway Campus, Lusaka, Zambia
| | - N. Beyers
- Desmond Tutu TB Centre, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
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Sattar S, Van Schalkwyk C, Claassens M, Dunbar R, Floyd S, Enarson DA, Godfrey-Faussett P, Ayles H, Beyers N. Symptom reporting among prevalent tuberculosis cases who smoke, are HIV-positive or have hyperglycaemia. Public Health Action 2014; 4:222-5. [PMID: 26400700 DOI: 10.5588/pha.14.0081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/18/2014] [Indexed: 11/10/2022] Open
Abstract
Data from a tuberculosis (TB) prevalence survey conducted in 24 communities in Zambia and the Western Cape, South Africa, January-December 2010, were analysed to determine the influence of smoking, hyperglycaemia and human immunodeficiency virus (HIV) infection on TB symptom reporting in culture-confirmed TB cases. Of 123 790 adults eligible for enrolment, 90 601 (73%) consented and 64 463 had evaluable sputum samples. ORs and 95%CIs were calculated using a robust standard errors logistic regression model adjusting for clustering at community level. HIV-positive TB cases were more likely to report cough, weight loss, night sweats and chest pain than non-HIV-positive TB cases. TB cases who smoked or had hyperglycaemia did not report symptoms differently from cases without these comorbidities.
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Affiliation(s)
- S Sattar
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - C Van Schalkwyk
- South African Centre for Epidemiological Modelling and Analysis, University of Stellenbosch, Cape Town, South Africa
| | - M Claassens
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - R Dunbar
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - S Floyd
- London School of Hygiene & Tropical Medicine, London, UK
| | - D A Enarson
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | | | - H Ayles
- ZAMBART Project, University of Zambia Ridgeway Campus, Lusaka, Zambia
| | - N Beyers
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
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Crawford MJ, Killaspy H, Barnes TR, Barrett B, Byford S, Clayton K, Dinsmore J, Floyd S, Hoadley A, Johnson T, Kalaitzaki E, King M, Leurent B, Maratos A, O'Neill FA, Osborn D, Patterson S, Soteriou T, Tyrer P, Waller D. Group art therapy as an adjunctive treatment for people with schizophrenia: a randomised controlled trial (MATISSE). Health Technol Assess 2012; 16:iii-iv, 1-76. [PMID: 22364962 DOI: 10.3310/hta16080] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE To examine the clinical effectiveness and cost-effectiveness of referral to group art therapy plus standard care, compared with referral to an activity group plus standard care and standard care alone, among people with schizophrenia. DESIGN A three-arm, parallel group, single-blind, pragmatic, randomised controlled trial. Participants were randomised via an independent and remote telephone randomisation service using permuted blocks, stratified by study centre. SETTING Study participants were recruited from secondary care mental health and social services in four UK centres. PARTICIPANTS Potential participants were aged 18 years or over, had a clinical diagnosis of schizophrenia, confirmed by an examination of case notes, and provided written informed consent. We excluded those who were unable to speak sufficient English to complete the baseline assessment, those with severe cognitive impairment and those already receiving arts therapy. INTERVENTIONS Group art therapy was delivered by registered art therapists according to nationally agreed standards. Groups had up to eight members, lasted for 90 minutes and ran for 12 months. Members were given access to a range of art materials and encouraged to use these to express themselves freely. Activity groups were designed to control for the non-specific effects of group art therapy. Group facilitators offered various activities and encouraged participants to collectively select those they wanted to pursue. Standard care involved follow-up from secondary care mental health services and the option of referral to other services, except arts therapies, as required. MAIN OUTCOME MEASURES Our co-primary outcomes were global functioning (measured using the Global Assessment of Functioning Scale - GAF) and mental health symptoms (measured using the Positive and Negative Syndrome Scale - PANSS) at 24 months. The main secondary outcomes were level of group attendance, social functioning, well-being, health-related quality of life, service utilisation and other costs measured 12 and 24 months after randomisation. RESULTS Four hundred and seventeen people were recruited, of whom 355 (85%) were followed up at 2 years. Eighty-six (61%) of those randomised to art therapy and 73 (52%) of those randomised to activity groups attended at least one group. No differences in primary outcomes were found between the three study arms. The adjusted mean difference between art therapy and standard care at 24 months was -0.9 [95% confidence interval (CI) -3.8 to 2.1] on the GAF Scale and 0.7 (95% CI -3.1 to 4.6) on the PANSS Scale. Differences in secondary outcomes were not found, except that those referred to an activity group had fewer positive symptoms of schizophrenia at 24 months than those randomised to art therapy. Secondary analysis indicated that attendance at art therapy groups was not associated with improvements in global functioning or mental health. Although the total cost of the art therapy group was lower than the cost of the two comparison groups, referral to group art therapy did not appear to provide a cost-effective use of resources. CONCLUSIONS Referring people with established schizophrenia to group art therapy as delivered in this randomised trial does not appear to improve global functioning or mental health of patients or provide a more cost-effective use of resources than standard care alone. TRIAL REGISTRATION Current Controlled Trials ISRCTN 46150447. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 8. See the HTA programme website for further project information.
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Affiliation(s)
- M J Crawford
- Centre for Mental Health, Imperial College London, London, UK.
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McWilliams L, Su K, Liang X, Floyd S, Amos J, Moody M, Kelsoe G, Kuraoka M. CD27+ Developing B Cells are Common in Human Fetal Liver. J Allergy Clin Immunol 2012. [DOI: 10.1016/j.jaci.2011.12.906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Behera MK, Sharma A, Dutta S, Sharma S, Julka PK, Rath GK, Kil WJ, Ko C, Kaushal A, Warran K, Ning H, Camphausen K, Smart D, Vern-Gross TZ, McMullen KP, Case LD, Bourland JD, Ellis TL, Lawrence JA, Tatter SB, Shaw EG, Urbanic JJ, Chan MD, Jensen RL, Shrieve DC, Mohindra P, Robins HI, Tome WA, Howard SP, Chen C, Damek D, Gaspar LE, Ney D, Waziri A, Lillehei K, Kavanagh BD, Wang CC, Floyd S, Chang CH, Warnke P, Chio CC, Kasper E, Mahadevan A, Wong E, Jeyapalan S, Chen C, Mahajan A, Grosshans D, McAleer MF, Brown PD, Chintagumpala M, Vats T, Puduvalli V, Yock T, Schulder M, Herschmann Y, Ghaly M, Knisely J, Ghaly M, Kapur A, Schulder M, Knisely J, Goetz P, Lwu S, Ebinu J, Arayee M, Monsalves E, Laperriere N, Menard C, Bernstein M, Zadeh G, Loganathan AG, Chan MD, Alphonse N, Peiffer AM, Johnson A, McMullen KP, Urbanic JJ, Saconn PA, Bourland JD, Munley MT, Shaw EG, Tatter SB, Ellis TL, Lwu S, Goetz P, Aryaee M, Monsalves E, Laperriere N, Menard C, Bernstein M, Zadeh G, Mahajan A, Lowe C, McAleer MF, Grosshans D, DeGroot J, Mark G, Vats T, Brown PD, Ruda R, Trevisan E, Magliola U, Bertero L, Bosa C, Ricardi U, Soffietti R, Rajappa P, Margetis K, Wernicke AG, Sherr DL, Lavi E, Fine RL, Schwartz T, Pannullo SC, Laack N, Blanchard M, Buckner J, Glass J, Andrews DW, Werner-Wasik M, Evans J, Lawrence YR, Shi W, Strauss I, Corn BW, Matceyevsky D, Alani S, Gez E, Shtraus N, Kanner AA, Spasic M, Choy W, Nagasawa D, Yang I, Noel M, Woolf E, Smith R, Castillo-Rojas P, Sorenson S, Smith K, Scheck AC, Han SJ, Oh MC, Sughrue ME, Rutkowski MJ, Aranda D, Barani IJ, Parsa AT, Redmond KJ, Horska A, Ishaq O, Ford E, McNutt T, Batra S, Kleinberg L, Wharam M, Mahone M, Terezakis S, Ryu S, Rock J, Movsas B, Mikkelsen T, Rosenblum M, Sabsevitz D, Bovi JA, Leo P, LaViolette P, Rand S, Mueller W, Phillips A, Venkatramani R, Olch A, Grimm J, Davidson T, Brown R, Dhall G, Finlay J, Wong K. RADIATION THERAPY. Neuro Oncol 2011. [DOI: 10.1093/neuonc/nor160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Birdthistle I, Mayanja B, Maher D, Floyd S, Seeley J, Weiss H. O2-S6.01 Non-consensual sex and association with HIV infection among women: a Cohort Study in rural Uganda, 1990-2008. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050109.97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Glynn J, Kayuni N, Banda E, Parrott F, Floyd S, Tanton C, Hemmings J, Molesworth A, Crampin A, French N. O2-S3.02 Assessing the validity of sexual behaviour reports in a whole population survey in rural Malawi. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050109.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Glynn J, Price A, Floyd S, Molesworth A, Kayuni N, Chihana M, Nyirenda V, Crampin A, French N. P1-S6.53 Antiretroviral therapy reduces HIV transmission in discordant couples in Northern Malawi. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crampin A, Kasimba S, Mwaungulu NJ, Dacombe R, Floyd S, Glynn JR, Fine PEM. Married to M. tuberculosis: risk of infection and disease in spouses of smear-positive tuberculosis patients. Trop Med Int Health 2011; 16:811-8. [PMID: 21447058 DOI: 10.1111/j.1365-3156.2011.02763.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To quantify the risk of infection and disease in spouses of tuberculosis patients and the extent to which intervention could reduce the risk in this highly exposed group. METHODS We compared HIV prevalence, TB prevalence and incidence and tuberculin skin test (TST) results in spouses of TB patients and community controls. HIV-positive spouses were offered isoniazid preventive therapy (IPT), and TST was repeated at 6, 12 and 24 months. RESULTS We recruited 148 spouses of smear-positive patients ascertained prospectively and 3% had active TB. We identified 203 spouses of previously diagnosed smear-positive patients, 11 had already had TB, and the rate of TB was 2.4 per 100 person years(py) over 2 years (95% CI 1.15-5.09). 116 were found alive and recruited. HIV prevalence was 37% and 39% in the prospective and retrospective spouse groups and 17% in controls. TST was ≥10 mm in 80% of HIV negative and in 57% of HIV-positive spouses ascertained retrospectively; 74% HIV negative and 62% HIV-positive spouses ascertained prospectively, and 48% HIV negative and 26% HIV-positive community controls. Of 54 HIV-positive spouses, 18 completed 6-month IPT. At 2 year follow-up, 87% of surviving spouses had TST ≥10 mm and the rate of TB was 1.1 per 100 py (95% CI 0.34-3.29). CONCLUSIONS Spouses are a high-risk group who should be screened for HIV and active TB. TST prevalence was already high by the time the spouses were approached but further infections were seen to occur. Uptake and adherence to IPT was disappointing, lessening the impact of short-duration therapy.
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Floyd S, O'Shea B, Darker C. General practitioners experience in dietary counselling; poor access to dietetic services. Ir Med J 2011; 104:59. [PMID: 21465883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Birdthistle IJ, Floyd S, Mwanasa S, Nyagadza A, Gwiza E, Glynn JR. Child sexual abuse and links to HIV and orphanhood in urban Zimbabwe. J Epidemiol Community Health 2010; 65:1075-82. [DOI: 10.1136/jech.2009.094359] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Jahn A, Floyd S, Crampin AC, Mvula H, Mwinuka V, Mwaiyeghele E, McGrath N, Zaba B, Fine PEM, Glynn JR. Declining child mortality in northern Malawi despite high rates of infection with HIV. Bull World Health Organ 2010; 88:746-53. [PMID: 20931059 DOI: 10.2471/blt.09.075085] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 03/01/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE To determine whether routine surveys, such as the Demographic and Health Surveys (DHS), have underestimated child mortality in Malawi. METHODS Rates and causes of child mortality were obtained from a continuous-registration demographic surveillance system (DSS) in Malawi for a population of 32 000. After initial census, births and deaths were reported by village informants and updated monthly by project enumerators. Cause of death was established by verbal autopsy whenever possible. The likely impact of human immunodeficiency virus (HIV) infection on child mortality was also estimated from antenatal clinic surveillance data. Overall and age-specific mortality rates were compared with those from the 2004 Malawi DHS. FINDINGS Between August 2002 and February 2006, 38 617 person-years of observation were recorded for 20 388 children aged < 15 years. There were 342 deaths. Re-census data, follow-up visits at 12 months of age and the ratio of stillbirths to neonatal deaths suggested that death registration by the DSS was nearly complete. Infant mortality was 52.7 per 1000 live births, under-5 mortality was 84.8 per 1000 and under-15 mortality was 99.1 per 1000. One-fifth of deaths by age 15 were attributable to HIV infection. Child mortality rates estimated with the DSS were approximately 30% lower than those from national estimates as determined by routine surveys. CONCLUSION The fact that child mortality rates based on the DSS were relatively low in the study population is encouraging and suggests that the low mortality rates estimated nationally are an accurate reflection of decreasing rates.
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Affiliation(s)
- A Jahn
- Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, England
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Floyd S, Pawashe C, Sitti M. Two-Dimensional Contact and Noncontact Micromanipulation in Liquid Using an Untethered Mobile Magnetic Microrobot. IEEE T ROBOT 2009. [DOI: 10.1109/tro.2009.2028761] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Marston M, Slaymaker E, Cremin I, Floyd S, McGrath N, Kasamba I, Lutalo T, Nyirenda M, Ndyanabo A, Mupambireyi Z, Zaba B. Trends in marriage and time spent single in sub-Saharan Africa: a comparative analysis of six population-based cohort studies and nine Demographic and Health Surveys. Sex Transm Infect 2009; 85 Suppl 1:i64-71. [PMID: 19307343 PMCID: PMC2654103 DOI: 10.1136/sti.2008.034249] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2009] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To describe trends in age at first sex (AFS), age at first marriage (AFM) and time spent single between events and to compare age-specific trends in marital status in six cohort studies. METHODS Cohort data from Uganda, Tanzania, South Africa, Zimbabwe and Malawi and Demographic and Health Survey (DHS) data from Uganda, Tanzania and Zimbabwe were analysed. Life table methods were used to calculate median AFS, AFM and time spent single. In each study, two surveys were chosen to compare marital status by age and identify changes over time. RESULTS Median AFM was much higher in South Africa than in the other sites. Between the other populations there were considerable differences in median AFS and AFM (AFS 17-19 years for men and 16-19 years for women, AFM 21-24 years and 18-19 years, respectively, for the 1970-9 birth cohort). In all surveys, men reported a longer time spent single than women (median 4-7 years for men and 0-2 years for women). Median years spent single for women has increased, apart from in Manicaland. For men in Rakai it has decreased slightly over time but increased in Kisesa and Masaka. The DHS data showed similar trends to those in the cohort data. The age-specific proportion of married individuals has changed little over time. CONCLUSIONS Median AFS, AFM and time spent single vary considerably among these populations. These three measures are underlying determinants of sexual risk and HIV infection, and they may partially explain the variation in HIV prevalence levels between these populations.
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Affiliation(s)
- M Marston
- Centre for Population Studies, London School of Hygiene and Tropical Medicine, London, UK.
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Mitrofanov IG, Sanin AB, Golovin DV, Litvak ML, Konovalov AA, Kozyrev AS, Malakhov AV, Mokrousov MI, Tretyakov VI, Troshin VS, Uvarov VN, Varenikov AB, Vostrukhin AA, Shevchenko VV, Shvetsov VN, Krylov AR, Timoshenko GN, Bobrovnitsky YI, Tomilina TM, Grebennikov AS, Kazakov LL, Sagdeev RZ, Milikh GN, Bartels A, Chin G, Floyd S, Garvin J, Keller J, McClanahan T, Trombka J, Boynton W, Harshman K, Starr R, Evans L. Experiment LEND of the NASA Lunar Reconnaissance Orbiter for high-resolution mapping of neutron emission of the Moon. Astrobiology 2008; 8:793-804. [PMID: 18844457 DOI: 10.1089/ast.2007.0158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The scientific objectives of neutron mapping of the Moon are presented as 3 investigation tasks of NASA's Lunar Reconnaissance Orbiter mission. Two tasks focus on mapping hydrogen content over the entire Moon and on testing the presence of water-ice deposits at the bottom of permanently shadowed craters at the lunar poles. The third task corresponds to the determination of neutron contribution to the total radiation dose at an altitude of 50 km above the Moon. We show that the Lunar Exploration Neutron Detector (LEND) will be capable of carrying out all 3 investigations. The design concept of LEND is presented together with results of numerical simulations of the instrument's sensitivity for hydrogen detection. The sensitivity of LEND is shown to be characterized by a hydrogen detection limit of about 100 ppm for a polar reference area with a radius of 5 km. If the presence of ice deposits in polar "cold traps" is confirmed, a unique record of many millions of years of lunar history would be obtained, by which the history of lunar impacts could be discerned from the layers of water ice and dust. Future applications of a LEND-type instrument for Mars orbital observations are also discussed.
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Affiliation(s)
- I G Mitrofanov
- Institute for Space Research of the Russian Academy of Sciences, Moscow, Russia.
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Crampin AC, Floyd S, Ngwira BM, Mwinuka V, Mwaungulu JN, Branson K, Fine PEM, Glynn JR. Assessment and evaluation of contact as a risk factor for tuberculosis in rural Africa. Int J Tuberc Lung Dis 2008; 12:612-618. [PMID: 18492326 PMCID: PMC2443279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
SETTING A rural district in Malawi. OBJECTIVE To determine the effect of inaccurate recall on estimates of the proportion of tuberculosis (TB) cases attributable to contact with identifiable prior cases. DESIGN Case-control study of laboratory-confirmed TB cases and community controls, comparing family, household and area contacts identified from a database of TB cases with those named at interview. Estimation of prior contact as a risk factor for TB and identified factors associated with being a named contact. RESULTS Ninety-five per cent of named contacts were known TB cases. The proportion of total identified contacts who were named at interview was 75%, and was similar for cases and controls. Cases were twice as likely as controls to identify prior contacts. Adding database information did not affect odds ratios, but increased the proportion of TB cases attributable to prior contact. Smear-positive, male and human immunodeficiency virus (HIV) negative TB patients were more likely to be named by subsequent cases. Identifiable recent contact with known smear-positive cases accounted for 12.5% of the TB burden. CONCLUSIONS Reporting of putative source contacts showed little evidence of recall bias and gave estimates of the relative risk of TB associated with identifiable contact. The lower likelihood of HIV-positive cases being named as contacts may reflect reduced infectiousness.
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Jahn A, Floyd S, Mwinuka V, Mwafilaso J, Mwagomba D, Mkisi RE, Katsulukuta A, Khunga A, Crampin AC, Branson K, McGrath N, Fine PEM. Ascertainment of childhood vaccination histories in northern Malawi. Trop Med Int Health 2008; 13:129-38. [DOI: 10.1111/j.1365-3156.2007.01982.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Miiro GM, Todd J, Nakubulwa S, Watera C, Hughes P, Munderi P, Floyd S, Grosskurth H. Evaluating affordable screening markers to detect HIV-1-infected Ugandan adults with CD4 counts of less than 200 cells/mul. J Int AIDS Soc 2008. [DOI: 10.1186/1758-2652-11-s1-p11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Floyd S, Crampin AC, Glynn JR, Madise N, Mwenebabu M, Mnkhondia S, Ngwira B, Zaba B, Fine PEM. The social and economic impact of parental HIV on children in northern Malawi: retrospective population-based cohort study. AIDS Care 2007; 19:781-90. [PMID: 17573599 PMCID: PMC6485412 DOI: 10.1080/09540120601163227] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
From population-based surveys in the 1980s in Karonga district, northern Malawi, 197 'index individuals' were identified as HIV-positive. 396 HIV-negative 'index individuals' were selected as a comparison group. These individuals, and their spouses and children, were followed up in 1998-2000. 582 of 593 index individuals were traced. 487 children of HIV-positive, and 1493 children of HIV-negative, parents were included in analyses. Rates of paternal, maternal, and double orphanhood among children with one or both parents HIV-positive were respectively 6, 8, and 17 times higher than for children with HIV-negative parents. Around 50% of children living apart from both parents had a grandparent as their guardian; for most of the rest the guardian was an aunt, uncle, or sibling. There were no child-headed households. Almost all children aged 6-14 were attending primary school. There was no evidence that parental HIV affected primary school attainment among children <15 years old. Children of HIV-positive parents were less likely to have attended secondary school than those of HIV-negative parents. The extended family has mitigated the impact of orphanhood on children, but interventions to reduce the incidence of orphanhood, and/or which strengthen society's ability to support orphans, are essential, especially as the HIV epidemic matures and its full impact is felt.
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Affiliation(s)
- S Floyd
- London School of Hygiene and Tropical Medicine, London, UK.
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Weir RE, Black GF, Nazareth B, Floyd S, Stenson S, Stanley C, Branson K, Sichali L, Chaguluka SD, Donovan L, Crampin AC, Fine PEM, Dockrell HM. The influence of previous exposure to environmental mycobacteria on the interferon-gamma response to bacille Calmette-Guérin vaccination in southern England and northern Malawi. Clin Exp Immunol 2007; 146:390-9. [PMID: 17100757 PMCID: PMC1810413 DOI: 10.1111/j.1365-2249.2006.03222.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We report a large study of the effect of BCG vaccination on the in vitro 6-day whole blood interferon-gamma (IFN-gamma) response to antigens from eight species of mycobacteria among schoolchildren in south-eastern England, where bacille Calmette-Guérin (BCG) vaccination is highly protective against pulmonary tuberculosis, and among young adults in northern Malawi, where BCG vaccination is not protective. In the UK children, BCG induced an appreciable increase in IFN-gamma response to antigens from most species of mycobacteria. The degree of change was linked to the relatedness of the species to Mycobacterium bovis BCG, and provides further evidence of the cross-reactivity of mycobacterial species in priming of the immune system. IFN-gamma responses to purified protein derivatives (PPDs) from M. tuberculosis and environmental mycobacteria were more prevalent in the Malawian than the UK group prior to vaccination; BCG vaccination increased the prevalence of responses to these PPDs in the UK group to a level similar to that in Malawi. There was no evidence that the vaccine-induced change in IFN-gamma response was dependent upon the magnitude of the initial response of the individual to environmental mycobacteria in the United Kingdom or in Malawi. These observations should assist the development and interpretation of human clinical trials of new vaccines against M. tuberculosis in areas of both low and high exposure to environmental mycobacteria.
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Affiliation(s)
- R E Weir
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
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Dacombe RJ, Crampin AC, Floyd S, Randall A, Ndhlovu R, Bickle Q, Fine PEM. Time delays between patient and laboratory selectively affect accuracy of helminth diagnosis. Trans R Soc Trop Med Hyg 2006; 101:140-5. [PMID: 16824566 DOI: 10.1016/j.trstmh.2006.04.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 04/07/2006] [Accepted: 04/13/2006] [Indexed: 01/10/2023] Open
Abstract
Studies of intestinal helminth infections are influenced by the constraints of sample collection, as identification of helminth ova in stools is affected by the time since evacuation from the host. Different methods may be required to optimise diagnostic sensitivity under different study conditions. In the context of studies in rural Malawi, we collected stool samples with different time delays from production by subjects to sample collection by field staff, to examination in the laboratory. Stools were processed by Kato-Katz (KK) or formol-ether concentration (FEC) methods. Hookworm and Schistosoma mansoni were the most common helminths identified. The prevalence of hookworm was higher with KK (270/988, 27%) than with FEC (191/988, 19%). Comparison was made between the results from the two methods according to the timing of the processing steps. Delays in processing did not affect retrieval of S. mansoni. A decrease in sensitivity of almost 50% for detection of hookworm was observed with either method when preservation/refrigeration was delayed by more than 3h. A delay of 1 day from refrigeration or preservation to laboratory processing also reduced the sensitivity for hookworm by 50% for both methods. Care must be taken in studies of multiple helminth infections owing to the selective reduction of hookworm ova during transport. This is particularly critical when samples are not preserved, even over short periods of time, and even with formalin preservation.
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Affiliation(s)
- R J Dacombe
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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Colgan HA, Floyd S, Noone EJ, Gibney MJ, Roche HM. Increased intake of fruit and vegetables and a low-fat diet, with and without low-fat plant sterol-enriched spread consumption: effects on plasma lipoprotein and carotenoid metabolism. J Hum Nutr Diet 2004; 17:561-9; quiz 571-4. [PMID: 15546434 DOI: 10.1111/j.1365-277x.2004.00564.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Regular intake of plant sterol (phytosterol)-enriched foods enhances the cholesterol lowering effect of diets. One side effect associated with plant sterol consumption is a modest reduction in plasma carotenoid concentrations. This study investigated the effect of consuming a low-fat National Cholesterol Education Programme (NCEP) Step 1 diet, including a low-fat plant sterol ester (PSE)-enriched spread on cholesterol metabolism to determine if specific dietary advice to increase daily fruit and vegetable intake could prevent reduced plasma carotenoid concentrations. MATERIALS AND METHODS In this randomised, crossover double-blind trial, 48 hypercholesterolaemic men received 21 g day(-1) of a low-fat PSE-enriched spread or placebo for 3 weeks, interrupted by 3 weeks washout. Individuals also adhered to a NCEP Step 1 diet and repeated 3-day food diaries monitored adherence. Specific advice was provided to increase dietary fruit and vegetable intakes. Fasting blood samples were collected at pre- and post-intervention for lipoprotein and carotenoid analysis. RESULTS Plasma total and low-density lipoprotein (LDL) cholesterol concentrations were significantly (P <0.05) reduced, by 4.6 and 7.1%, respectively, after the PSE-enriched low-fat spread. Plasma apo B concentrations were significantly (P <0.0005) lower after the PSE spread. PSE consumption was also associated with significantly (P <0.05) lower total plasma beta-carotene concentrations, but this change was not significant after lipid standardisation. PSE consumption had no effect on retinol, alpha-carotene, gamma-tocopherol, alpha-tocopherol, lutein, zeaxanthin, beta-crypyoxanthin or lycopene concentrations. CONCLUSION Dietary advice to increase daily fruit and vegetable consumption may be effective in preventing a reduction in plasma carotenoid concentrations previously associated with PSE consumption. Further, PSE incorporated in a low-fat spread and consumed as part of a NCEP Step 1 diet are effective in reducing total and LDL cholesterol.
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Affiliation(s)
- H A Colgan
- Unit of Nutrition, Department of Clinical Medicine, Trinity Health Sciences Centre, St James's Hospital, Dublin, Ireland
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Crampin AC, Glynn JR, Floyd S, Malema SS, Mwinuka VK, Ngwira BMM, Mwaungulu FD, Warndorff DK, Fine PEM. Tuberculosis and gender: exploring the patterns in a case control study in Malawi. Int J Tuberc Lung Dis 2004; 8:194-203. [PMID: 15139448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND In many populations there is an excess of tuberculosis in young women and older men. We explored possible explanations for these patterns, concentrating on human immunodeficiency virus (HIV) status, pregnancy, smoking, cooking smoke exposure, contact with tuberculosis cases within the household or outside, and gender differences in health service usage and diagnostic delay. DESIGN Case control study in Karonga District, Malawi. METHODS Cases were new tuberculosis patients with bacteriological or histological evidence of tuberculosis. Controls were selected in the community using field-based random sampling. RESULTS The study included 598 tuberculosis cases and 992 controls, with an excess of tuberculosis in young females and older males. This was more marked in HIV-positive individuals. HIV infection was a similarly strong risk factor for tuberculosis in both men and women. Tuberculosis was associated with having a family or household contact with tuberculosis for both men and women. For women, but not men, contacts outside the close family and household were also a risk factor for tuberculosis. Tuberculosis was not associated with current or recent pregnancy, or with smoking or smoke exposure. There were no differences between men and women in health service usage or delay. CONCLUSIONS In this population, HIV infection and contacts with known tuberculosis patients are important determinants of the gender distribution of cases.
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Weir RE, Fine PEM, Nazareth B, Floyd S, Black GF, King E, Stanley C, Bliss L, Branson K, Dockrell HM. Interferon-gamma and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria. Clin Exp Immunol 2003; 134:285-94. [PMID: 14616789 PMCID: PMC1808851 DOI: 10.1046/j.1365-2249.2003.02272] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon-gamma (IFN-gamma) responses to M. tuberculosis purified protein derivative (PPD), and IFN-gamma responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13-15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN-gamma response and in 20% by the Heaf test. IFN-gamma responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45-60% responders). Heaf test and IFN-gamma responses were associated (P<0.001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis.
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Affiliation(s)
- R E Weir
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
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Bierrenbach AL, Floyd S, Cunha SC, Dourado I, Barreto ML, Pereira SM, Hijjar MA, Rodrigues LC. A comparison of dual skin test with mycobacterial antigens and tuberculin skin test alone in estimating prevalence of Mycobacterium tuberculosis infection from population surveys. Int J Tuberc Lung Dis 2003; 7:312-9. [PMID: 12729335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
SETTING City of Manaus, Amazonas, Brazil. OBJECTIVE To compare estimates of Mycobacterium tuberculosis infection prevalence obtained using traditional tuberculin skin test (TST) criteria and dual skin test (DST) data. METHODS A total of 1070 schoolchildren received DST with tuberculin and four environmental mycobacteria sensitins. Responses were classified as sensitin-dominant, tuberculin-dominant or non-dominant. Positive predictive values (PPV) were defined using 'narrow' and 'wide' standards based on DST responses. These predictive values were derived for each category of tuberculin indurations, and were used to calculate the prevalence estimates. RESULTS Using DST data, the estimates of M. tuberculosis prevalence for scar-negative children were 7.4% (M. avium) and 7.8% (M. scrofulaceum) using the 'narrow' standard, and 16.9% (M. avium) and 15.2% (M. scrofulaceum) using the 'wide' standard. The percentage with TST > or =10 mm was 11.5%. Scar-positive children had higher estimates using both the 10 mm cut-off and DST data. CONCLUSION In settings with a relatively low prevalence of M. tuberculosis infection and high cross-reactivity with environmental mycobacteria, DST can help to assess the validity of traditional thresholds for estimating the prevalence of M. tuberculosis infection. DST data with environmental antigens and tuberculin do not distinguish BCG-induced cross-reactivity.
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Affiliation(s)
- A L Bierrenbach
- Department of Infectious & Tropical Disease, London School of Hygiene & Tropical Medicine, London, UK.
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Schmierer K, Grosse P, De Camilli P, Solimena M, Floyd S, Zschenderlein R. Paraneoplastic stiff-person syndrome: no tumor progression over 5 years. Neurology 2002; 58:148. [PMID: 11781426 DOI: 10.1212/wnl.58.1.148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- K Schmierer
- Department of Neurology, Charité, Humboldt University, Berlin, Germany.
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Randall AE, Perez MA, Floyd S, Black GF, Crampin AC, Ngwira B, Pistoni WN, Mulawa D, Sichali L, Mwaungulu L, Bickle Q, Fine PEM. Patterns of helminth infection and relationship to BCG vaccination in Karonga District, northern Malawi. Trans R Soc Trop Med Hyg 2002; 96:29-33. [PMID: 11925985 DOI: 10.1016/s0035-9203(02)90229-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Surveys of enteric and urinary helminth infections were carried out in 1999 among 501 schoolchildren and among 320 adolescents and young adults participating in a study of immune responses to BCG vaccine in Karonga District, northern Malawi. Hookworm, Schistosoma mansoni and S. haematobium infections were detected in 64%, 27% and 20% of schoolchildren and in 55%, 40% and 25% of the immunology study subjects, respectively. Other helminths were appreciably less common. The prevalence of 'at least one' helminth infection was 76% among schoolchildren, ranging from 60% to 92% in the 4 schools, and was 79% in the immunology study participants. There was no evidence for an association between the presence of a BCG scar and presence or intensity of infection with worms in the schoolchildren, nor evidence that BCG vaccination of adolescents and young adults had any effect on the prevalence of helminth infections 1 year later.
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Affiliation(s)
- A E Randall
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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Crampin AC, Floyd S, Mwaungulu F, Black G, Ndhlovu R, Mwaiyeghele E, Glynn JR, Warndorff DK, Fine PE. Comparison of two versus three smears in identifying culture-positive tuberculosis patients in a rural African setting with high HIV prevalence. Int J Tuberc Lung Dis 2001; 5:994-9. [PMID: 11716350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
SETTING Karonga district, northern Malawi. OBJECTIVE To compare the sensitivity and specificity of two versus three smears for the diagnosis of pulmonary tuberculosis in a setting with high HIV prevalence. DESIGN A total of 1992 pulmonary tuberculosis suspects with three sputum smears taken over a 2-7 day period and at least one culture result were studied. Smears were auramine stained and examined using fluorescence microscopy, and positives were confirmed with Ziehl-Neelsen staining and light microscopy. Cultures were set up on Löwenstein-Jensen media. True negative and positive status was defined on the basis of culture. The sensitivity, specificity, and positive and negative predictive values of two and three smears were compared. RESULTS Compared to culture, the sensitivity, specificity, and positive and negative predictive values of three smears were 70%, 98%, 92%, and 92%, respectively. Restriction to the first two smears gave similar results. Of those detected as smear-positive using three smears, at least 97% would have been detected by two. Among those with HIV serology results available, the sensitivity of two smears for detecting culture-positive tuberculosis was identical to that using three. CONCLUSION In this setting, using fluorescence and light microscopy, collecting two smears rather than three would only marginally reduce sensitivity and would slightly improve the specificity of diagnosis of tuberculosis; this is unaffected by HIV status. The potential for improving specificity is important because of the costs of misdiagnosis. In practice, both sensitivity and specificity may be increased due to the time saved by examining two rather than three smears.
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Black GF, Dockrell HM, Crampin AC, Floyd S, Weir RE, Bliss L, Sichali L, Mwaungulu L, Kanyongoloka H, Ngwira B, Warndorff DK, Fine PE. Patterns and implications of naturally acquired immune responses to environmental and tuberculous mycobacterial antigens in northern Malawi. J Infect Dis 2001; 184:322-9. [PMID: 11443558 DOI: 10.1086/322042] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2000] [Revised: 04/19/2001] [Indexed: 11/04/2022] Open
Abstract
Interferon (IFN)-gamma responsiveness to 12 purified protein derivative (PPD) and new tuberculin antigens from 9 species of mycobacteria was assessed, using a whole blood assay, in 616 young adults living in northern Malawi, where Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination provides no protection against pulmonary tuberculosis. The prevalence of IFN-gamma responsiveness was highest for PPDs of M. avium, M. intracellulare, and M. scrofulaceum (the MAIS complex). Correlations between responsiveness paralleled genetic relatedness of the mycobacterial species. A randomized, controlled trial was carried out, to assess the increase in IFN-gamma responsiveness to M. tuberculosis PPD that can be attributed to M. bovis BCG vaccination. The BCG-attributable increase in IFN-gamma response to M. tuberculosis PPD was greater for individuals with low initial responsiveness to MAIS antigens than for those with high initial responsiveness. Although not statistically significant, the trend is consistent with the hypothesis that prior exposure to environmental mycobacteria interferes with immune responses to BCG vaccination.
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Affiliation(s)
- G F Black
- Karonga Prevention Study, Chilumba, Malawi
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Gudrups I, Floyd S, Kling JG, Bosque-Perez NA, Orchard JE. A comparison of two methods of assessment of maize varietal resistance to the maize weevil, Sitophilus zeamais Motschulsky, and the influence of kernel hardness and size on susceptibility. J Stored Prod Res 2001; 37:287-302. [PMID: 11172865 DOI: 10.1016/s0022-474x(00)00031-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fifty-two maize varieties were screened for resistance to infestation by the maize weevil, Sitophilus zeamais, using assessment methods proposed by Dobie (J. Stored Products Res. 10 (1974) 183-197) and Urrelo et al. (J. Stored Products Res. 26 (1990) 100). The two methods gave similar assessments of maize susceptibility to S. zeamais. The Dobie method is preferred due to the lower total time required for assessment of relative susceptibility of maize varieties. The greatest disadvantage of the Urrelo method is the intensive labour requirements in the early stages of a trial, when numbers of eggs have to be counted, although it has the advantage that the assessment may be terminated upon emergence of the first F(1) adult. Two explanatory variables, kernel size and hardness, were investigated to determine whether they may be used as indicators of resistance. Results suggested that kernel size is the more important in determining resistance to attack by S. zeamais, with large kernels appearing to show greater resistance than small ones. Contrary to expectations, of the varieties tested, including local, hybrid and improved open pollinated (IOP) varieties, the local varieties were generally more susceptible. This may be related to kernel size, as all IOPs and hybrids tested had large kernels, whereas the majority of the local varieties had small ones. No clear relationship between weevil susceptibility and kernel hardness could be detected, although there was an indication that differences associated with kernel size varied depending on kernel hardness. None of the varieties tested showed high levels of resistance to attack by S. zeamais.
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Affiliation(s)
- I Gudrups
- Food Security Department, Natural Resources Institute, Central Avenue, Chatham Maritime, Chatham, ME4 4TB, Kent, UK
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Black GF, Warndorff DK, Floyd S, Weir RE, Blackwell JM, Bliss L, Sichali L, Mwaungulu L, Chaguluka S, Jarman E, Ngwira B, Dockrell HM. Relationship between IFN-gamma and skin test responsiveness to Mycobacterium tuberculosis PPD in healthy, non-BCG-vaccinated young adults in Northern Malawi. Int J Tuberc Lung Dis 2001; 5:664-72. [PMID: 11467373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
SETTING Rural northern Malawi, where vaccination with BCG Glaxo (1077) provides protection against leprosy but not against pulmonary tuberculosis. OBJECTIVE To evaluate the patterns of responsiveness to purified protein derivative of Mycobacterium tuberculosis (PPD) in terms of delayed type hypersensitivity (DTH) and interferon-gamma (IFN-gamma) production. DESIGN IFN-gamma was measured in 6 day whole blood cultures diluted 1 in 10, stimulated with PPD RT48, and the results compared to the DTH response to PPD RT23. A total of 633 individuals aged 12 to 28 years, without prior BCG vaccination, were recruited. RESULTS Overall, 63% of subjects made a positive IFN-gamma response (defined as >62 pg/ml), and 37% gave a DTH induration of >5 mm. A strong correlation between skin test and IFN-gamma responses was observed, although with interesting exceptions: 13/270 individuals with zero DTH showed IFN-gamma responses >500 pg/ml, and 7/53 individuals with >10 mm induration showed IFN-gamma responses < or = 62 pg/ml. The prevalence of skin test responsiveness increased with age, and was higher among older males than females; age-sex patterns were less clear for IFN-gamma production. CONCLUSION The 6 day IFN-gamma response to PPD correlates well with Mantoux skin test induration. The discordant individuals may represent important subsets in terms of protective immunity and risk of clinical tuberculosis.
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Affiliation(s)
- G F Black
- Karonga Prevention Study, Chilumba, Malawi
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Fine PE, Floyd S, Stanford JL, Nkhosa P, Kasunga A, Chaguluka S, Warndorff DK, Jenkins PA, Yates M, Ponnighaus JM. Environmental mycobacteria in northern Malawi: implications for the epidemiology of tuberculosis and leprosy. Epidemiol Infect 2001; 126:379-87. [PMID: 11467795 PMCID: PMC2869706 DOI: 10.1017/s0950268801005532] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
More than 36000 individuals living in rural Malawi were skin tested with antigens derived from 12 different species of environmental mycobacteria. Most were simultaneously tested with RT23 tuberculin, and all were followed up for both tuberculosis and leprosy incidence. Skin test results indicated widespread sensitivity to the environmental antigens, in particular to Mycobacterium scrofulaceum, M. intracellulare and one strain of M. fortuitum. Individuals with evidence of exposure to 'fast growers' (i.e. with induration to antigens from fast growers which exceeded their sensitivity to tuberculin), but not those exposed to 'slow growers', were at reduced risk of contracting both tuberculosis and leprosy, compared to individuals whose indurations to the environmental antigen were less than that to tuberculin. This evidence for cross protection from natural exposure to certain environmental mycobacteria may explain geographic distributions of mycobacterial disease and has important implications for the mechanisms and measurement of protection by mycobacterial vaccines.
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Affiliation(s)
- P E Fine
- Department of infectious at Tropical Diseases, London School of Hygiene and Tropical Medicine
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Crampin AC, Mwaungula F, Floyd S, Black GF, Ndhlovu R, Mwaiyeghele E, Glynn JR, Fine PEM. The value of two versus three smear in identifying culture postive tuberculosis patients in Karonga district. Malawi Med J 2001. [DOI: 10.4314/mmj.v13i4.10786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Floyd S, Ponnighaus JM, Bliss L, Warndorff DK, Kasunga A, Mogha P, Fine PE. BCG scars in northern Malawi: sensitivity and repeatability of scar reading, and factors affecting scar size. Int J Tuberc Lung Dis 2000; 4:1133-42. [PMID: 11144455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
SETTING Karonga district, northern Malawi. OBJECTIVE To assess the sensitivity and repeatability of BCG scar reading, and factors affecting scar size. DESIGN Follow-up of individuals aged > 3 months who were recruited into a BCG vaccine trial (1986-1989), and of infants vaccinated in health centres (1989-1991), who were examined for presence and size of BCG scars in subsequent years. All examinations were carried out blind of information on true vaccination status or the results of previous examinations. RESULTS For trial individuals who were considered scar negative at recruitment and received BCG, the sensitivity of scar reading was > or = 93%, repeatability was > or = 94% for those < 60 years old at vaccination, and only around 1% were assessed as having > 1 BCG scar post-vaccination. For infants vaccinated when < 1 month old in health centres, the proportion who still had recognisable scars 4 years later was < 80%. Scars were larger in individuals with a prior BCG vaccination, and for those aged 15-59 at vaccination the scars were approximately 1 mm larger for males than for females. CONCLUSIONS A BCG scar is a highly sensitive and repeatable indicator of vaccination status when the vaccine is properly handled, delivered appropriately, and given at over 3 months of age, but not for vaccinations given within 1 month of birth. Given that most vaccinations in the world are given soon after birth, this low sensitivity will lead to both vaccine coverage and vaccine efficacy being underestimated in studies in which vaccination status is inferred from the presence/absence of a distinctive BCG scar. Age-sex patterns identified for scar size show important similarities to those found with skin test responses to tuberculin.
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Affiliation(s)
- S Floyd
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK.
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Allen RW, Pritchard J, Harmon J, Floyd S. Phenotypic differences at the HUMvWA locus amplified with different STR kits. J Forensic Sci 2000; 45:1166-7. [PMID: 11005201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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