1
|
Denison JA, Willis K, DeLong SM, Sievwright KM, Agwu AL, Arrington-Sanders R, Kaufman MR, Prabhu S, Williams AM, Fields EL, Alexander KA, Lee L, Yang C. Advancing Adolescent and Young Adult HIV Prevention and Care and Treatment Through Use of Multi-level Theories and Frameworks: A Scoping Review and Adapted HIV Ecological Framework. AIDS Behav 2024; 28:1694-1707. [PMID: 38351279 PMCID: PMC11069483 DOI: 10.1007/s10461-023-04255-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2023] [Indexed: 05/05/2024]
Abstract
While multi-level theories and frameworks have become a cornerstone in broader efforts to address HIV inequities, little is known regarding their application in adolescent and young adult (AYA) HIV research. To address this gap, we conducted a scoping review to assess the use and application of multi-level theories and frameworks in AYA HIV prevention and care and treatment empirical research. We systematically searched five databases for articles published between 2010 and May 2020, screened abstracts, and reviewed eligible full-text articles for inclusion. Of the 5890 citations identified, 1706 underwent full-text review and 88 met the inclusion criteria: 70 focused on HIV prevention, with only 14 on care and treatment, 2 on both HIV prevention and care and treatment, and 2 on HIV-affected AYA. Most authors described the theory-based multi-level framework as informing their data analysis, with only 12 describing it as informing/guiding an intervention. More than seventy different multi-level theories were described, with 38% utilizing socio-ecological models or the eco-developmental theory. Findings were used to inform the adaptation of an AYA World Health Organization multi-level framework specifically to guide AYA HIV research.
Collapse
Affiliation(s)
- Julie A Denison
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street. Room E5546, Baltimore, MD, 21205, USA.
| | - Kalai Willis
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Stephanie M DeLong
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Kirsty M Sievwright
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street. Room E5546, Baltimore, MD, 21205, USA
- HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute and Columbia University, New York, US
| | - Allison L Agwu
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Michelle R Kaufman
- Department of Health, Behavior, and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Sandeep Prabhu
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street. Room E5546, Baltimore, MD, 21205, USA
| | - Ashlie M Williams
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street. Room E5546, Baltimore, MD, 21205, USA
| | - Errol L Fields
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Lana Lee
- Adult Clinical Branch, Office of HIV/AIDS, United States Agency for International Development, Washington, DC, USA
| | - Cui Yang
- Department of Health, Behavior, and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| |
Collapse
|
2
|
Silva JKBD, Santos JMD, Moreira WC, Romero ROG, Leadebal ODCP, Nogueira JDA. Modelo multinível na identificação de fatores de risco comportamentais e estruturais ao HIV: revisão integrativa. Rev Bras Enferm 2023. [DOI: 10.1590/0034-7167-2021-0853pt] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
RESUMO Objetivos: investigar estudos que adotaram o modelo de análise multinível na identificação de fatores de risco comportamentais e estruturais, que estão associados a infecção pelo HIV. Métodos: revisão integrativa da literatura com estudos disponíveis na íntegra, obtidos nas bases EMBASE, CINAHL, Pubmed e Scopus, cujos descritores selecionados foram os termos constantes: “HIV”, “multilevel analysis”, “behavior”. Resultados: a pesquisa resultou em 236 artigos. Destes, dez artigos compuseram a amostra. Desvantagem econômica, características de vizinhança, instabilidade habitacional, encarceramento, sexo transacional, múltiplos parceiros, abuso de substâncias e idade da primeira relação sexual foram classificados como fatores de risco estruturais e comportamentais ao HIV. Redução da desvantagem socioeconômica, fornecimento de estabilidade habitacional e uso de preservativos foram associados a fatores de proteção à exposição ao HIV. Conclusões: com a aplicabilidade do modelo multinível nos estudos de investigação de fatores de risco, foi possível identificar os elementos estruturais e comportamentais de risco ao HIV.
Collapse
|
3
|
da Silva JKB, dos Santos JM, Moreira WC, Romero ROG, Leadebal ODCP, Nogueira JDA. Multilevel model in the identification of behavioral and structural risk factors for HIV: integrative review. Rev Bras Enferm 2022; 76:e20210853. [PMID: 36542051 PMCID: PMC9749773 DOI: 10.1590/0034-7167-2021-0853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 08/21/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES to investigate studies that adopted the multilevel analysis model to identify behavioral and structural risk factors associated with HIV infection. METHODS an integrative review of the literature with studies available in full, obtained from EMBASE, CINAHL, Pubmed, and Scopus, whose selected descriptors were the indexed terms: "HIV", "multilevel analysis" and "behavior". RESULTS the search resulted in 236 studies. Out of these, ten studies comprised the sample. Economic disadvantage, neighborhood characteristics, housing instability, incarceration, transactional sex, multiple partners, substance abuse, and age at first intercourse were classified as structural and behavioral risk factors for HIV. Reduced socioeconomic disadvantage, provision of housing stability, and condom use were associated with protective factors for HIV exposure. CONCLUSIONS by applying the multilevel model in risk factor research studies, it was possible to identify the structural and behavioral elements of HIV risk.
Collapse
|
4
|
Dzomba A, Kim HY, Tomita A, Vandormael A, Govender K, Tanser F. Predictors of migration in an HIV hyper-endemic rural South African community: evidence from a population-based cohort (2005-2017). BMC Public Health 2022; 22:1141. [PMID: 35672845 PMCID: PMC9175358 DOI: 10.1186/s12889-022-13526-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Globally, South Africa hosts the highest number of people living with HIV (PLHIV) and the unique legacy of internal labour migration continues to be a major driver of the regional epidemic, interrupting treatment-as-prevention efforts. The study examined levels, trends, and predictors of migration in rural KwaZulu-Natal Province, South Africa, using population-based surveillance data from 2005 through 2017. We followed 69 604 adult participants aged 15-49 years and recorded their migration events (i.e., out-migration from the surveillance area) in 423 038 person-years over 525 397 observations. Multiple failure Cox-regression models were used to measure the risk of migration by socio-demographic factors: age, sex, educational status, marital status, HIV, and community antiretroviral therapy (ART) coverage. Overall, 69% of the population cohort experienced at least one migration event during the follow-up period. The average incidence rate of migration was 9.96 events and 13.23 events per 100 person-years in women and men, respectively. Migration rates declined from 2005 to 2008 then peaked in 2012 for both women and men. Adjusting for other covariates, the risk of migration was 3.4-times higher among young women aged 20-24 years compared to those aged ≥ 40 years (adjusted Hazard Ratio [aHR] = 3.37, 95% Confidence Interval [CI]: 3:19-3.57), and 2.9-times higher among young men aged 20-24 years compared to those aged ≥ 40 years (aHR = 2.86, 95% CI:2.69-3.04). There was a 9% and 27% decrease in risk of migration among both women (aHR = 0.91, 95% CI: 0.83 - 0.99) and men (aHR = 0.73, 95% CI 0.66 - 0.82) respectively per every 1% increase in community ART coverage. Young unmarried women including those living with HIV, migrated at a magnitude similar to that of their male counterparts, and lowered as ART coverage increased over time, reflecting the role of improved HIV services across space in reducing out-migration. A deeper understanding of the characteristics of a migrating population provides critical information towards identifying and addressing gaps in the HIV prevention and care continuum in an era of high mobility.
Collapse
Affiliation(s)
- Armstrong Dzomba
- Discipline of Public Health Medicine, Africa Health Research Institute(AHRI), University of KwaZulu-Natal, KwaZulu-Natal Province, K-RITH Tower Building, 719 Umbilo Road, Private Bag X7, Congella, Durban, South Africa.
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban, South Africa.
- Medical Research Council (MRC)/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), University of the Witwatersrand, Acornhoek, South Africa.
| | - Hae-Young Kim
- Discipline of Public Health Medicine, Africa Health Research Institute(AHRI), University of KwaZulu-Natal, KwaZulu-Natal Province, K-RITH Tower Building, 719 Umbilo Road, Private Bag X7, Congella, Durban, South Africa
- Department of Population Health, New York University Grossman School of Medicine, New York City, NY, USA
| | - Andrew Tomita
- Centre for Rural Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Alain Vandormael
- Heidelberg Institute of Global Health (HIGH), University of Heidelberg, Heidelberg, Germany
- Department of Medicine, Stanford University, Stanford, USA
| | - Kaymarlin Govender
- Health Economics and HIV and AIDS Research Division (HEARD), University of KwaZulu-Natal, Durban, South Africa
| | - Frank Tanser
- Discipline of Public Health Medicine, Africa Health Research Institute(AHRI), University of KwaZulu-Natal, KwaZulu-Natal Province, K-RITH Tower Building, 719 Umbilo Road, Private Bag X7, Congella, Durban, South Africa
- Centre for Rural Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
- Lincoln Institute for Health, University of Lincoln, Lincoln, LN6 7TS, UK
| |
Collapse
|
5
|
Spencer DC. SAHCS 2021 Conference Summary. South Afr J HIV Med 2022; 23:1371. [PMID: 35706547 PMCID: PMC9082288 DOI: 10.4102/sajhivmed.v23i1.1371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Affiliation(s)
- David C Spencer
- Division of Infectious Diseases, Faculty of Medicine, University of the Witwatersrand, Johannesburg, South Africa
- Southern African HIV Clinicians Society, Johannesburg, South Africa
| |
Collapse
|
6
|
Gareta D, Baisley K, Mngomezulu T, Smit T, Khoza T, Nxumalo S, Dreyer J, Dube S, Majozi N, Ording-Jesperson G, Ehlers E, Harling G, Shahmanesh M, Siedner M, Hanekom W, Herbst K. Cohort Profile Update: Africa Centre Demographic Information System (ACDIS) and population-based HIV survey. Int J Epidemiol 2021; 50:33-34. [PMID: 33437994 PMCID: PMC7938501 DOI: 10.1093/ije/dyaa264] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Dickman Gareta
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Kathy Baisley
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,London School of Hygiene and Tropical Medicine, Faculty of Epidemiology and Population Health, London, UK
| | | | - Theresa Smit
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Thandeka Khoza
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | | | - Jaco Dreyer
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Sweetness Dube
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | | | | | - Eugene Ehlers
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Guy Harling
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,Institute for Global Health, University College London, London, UK.,MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), University of the Witwatersrand, Johannesburg, South Africa.,Department of Epidemiology & Harvard Centre for Population and Development Studies, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Maryam Shahmanesh
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,Institute for Global Health, University College London, London, UK
| | - Mark Siedner
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,Harvard Medical School, Boston, MA, USA.,Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Willem Hanekom
- Africa Health Research Institute, KwaZulu-Natal, South Africa
| | - Kobus Herbst
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,SAPRIN, South African Medical Research Council, Cape Town, South Africa
| |
Collapse
|
7
|
Thiabaud A, Triulzi I, Orel E, Tal K, Keiser O. Social, Behavioral, and Cultural factors of HIV in Malawi: Semi-Automated Systematic Review. J Med Internet Res 2020; 22:e18747. [PMID: 32795992 PMCID: PMC7455873 DOI: 10.2196/18747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/20/2020] [Accepted: 06/04/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Demographic and sociobehavioral factors are strong drivers of HIV infection rates in sub-Saharan Africa. These factors are often studied in qualitative research but ignored in quantitative analyses. However, they provide in-depth insight into the local behavior and may help to improve HIV prevention. OBJECTIVE To obtain a comprehensive overview of the sociobehavioral factors influencing HIV prevalence and incidence in Malawi, we systematically reviewed the literature using a newly programmed tool for automatizing part of the systematic review process. METHODS Due to the choice of broad search terms ("HIV AND Malawi"), our preliminary search revealed many thousands of articles. We, therefore, developed a Python tool to automatically extract, process, and categorize open-access articles published from January 1, 1987 to October 1, 2019 in the PubMed, PubMed Central, JSTOR, Paperity, and arXiV databases. We then used a topic modelling algorithm to classify and identify publications of interest. RESULTS Our tool extracted 22,709 unique articles; 16,942 could be further processed. After topic modelling, 519 of these were clustered into relevant topics, of which 20 were kept after manual screening. We retrieved 7 more publications after examining the references so that 27 publications were finally included in the review. Reducing the 16,942 articles to 519 potentially relevant articles using the software took 5 days. Several factors contributing to the risk of HIV infection were identified, including religion, gender and relationship dynamics, beliefs, and sociobehavioral attitudes. CONCLUSIONS Our software does not replace traditional systematic reviews, but it returns useful results to broad queries of open-access literature in under a week, without a priori knowledge. This produces a "seed dataset" of relevance that could be further developed. It identified known factors and factors that may be specific to Malawi. In the future, we aim to expand the tool by adding more social science databases and applying it to other sub-Saharan African countries.
Collapse
Affiliation(s)
- Amaury Thiabaud
- Institut de Santé Globale, Université de Genève, Genève, Switzerland
| | - Isotta Triulzi
- Institut de Santé Globale, Université de Genève, Genève, Switzerland
- Institute of Management, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Erol Orel
- Institut de Santé Globale, Université de Genève, Genève, Switzerland
| | - Kali Tal
- Institut de Santé Globale, Université de Genève, Genève, Switzerland
- Institute of Primary Health Care (BIHAM), University of Bern, Bern, Switzerland
| | - Olivia Keiser
- Institut de Santé Globale, Université de Genève, Genève, Switzerland
| |
Collapse
|
8
|
Vandormael A, Cuadros D, Dobra A, Bärnighausen T, Tanser F. HIV incidence declines in a rural South African population: a G-imputation approach for inference. BMC Public Health 2020; 20:1205. [PMID: 32762668 PMCID: PMC7409400 DOI: 10.1186/s12889-020-09193-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 07/01/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ad hoc assumptions about the unobserved infection event, which is known only to occur between the latest-negative and earliest-positive test dates, can lead to biased HIV incidence rate estimates. Using a G-imputation approach, we infer the infection dates from covariate data to estimate the HIV incidence rate in a hyper-endemic South African setting. METHODS A large demographic surveillance system has annually tested a cohort of HIV-uninfected participants living in the KwaZulu-Natal province. Using this data, we estimated a cumulative baseline hazard function and the effects of time-dependent covariates on the interval censored infection dates. For each HIV-positive participant in the cohort, we derived a cumulative distribution function and sampled multiple infection dates conditional on the unique covariate values. We right censored the data at the imputed dates, calculated the annual HIV incidence rate per 100 person-years, and used Rubin's rules to obtain the 95% confidence intervals. RESULTS A total of 20,011 uninfected individuals with a repeat HIV test participated in the incidence cohort between 2005 and 2018. We observed 2,603 infections per 58,769 person-years of follow-up among women and 845 infections per 41,178 person-years of follow-up among men. Conditional on age and circumcision status (men only), the female HIV incidence rate declined by 25%, from 5.0 to 3.7 infections per 100 person-years between 2014 and 2018. During this period, the HIV incidence rate among men declined from 2.1 to 1.1 infections per 100 person-years-a reduction of 49%. We observed similar reductions in male and female HIV incidence conditional on condom-use, marital status, urban residential status, migration history, and the HIV prevalence in the surrounding community. CONCLUSION We have followed participants in one of the world's largest and longest running HIV cohorts to estimate long-term trends in the population-wide incidence of infection. Using a G-imputation approach, we present further evidence for HIV incidence rate declines in this hyper-endemic South African setting.
Collapse
Affiliation(s)
- Alain Vandormael
- Africa Health Research Institute (AHRI), Durban, South Africa. .,Heidelberg Institute of Global Health, University of Heidelberg, 130.3 Im Neuenheimer Feld, Heidelberg, 69115, Germany. .,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal (UKZN), Durban, South Africa.
| | - Diego Cuadros
- Department of Geography and Geographic Information Science, University of Cincinnati, Cincinnati, USA
| | - Adrian Dobra
- Department of Statistics, Center for Statistics and the Social Sciences, and Center for Studies in Demography and Ecology, University of Washington, Seattle, USA
| | - Till Bärnighausen
- Africa Health Research Institute (AHRI), Durban, South Africa.,Heidelberg Institute of Global Health, University of Heidelberg, 130.3 Im Neuenheimer Feld, Heidelberg, 69115, Germany.,Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, USA
| | - Frank Tanser
- Africa Health Research Institute (AHRI), Durban, South Africa.,Lincoln International Institute for Rural Health, University of Lincoln, Lincoln, UK.,School of Nursing and Public Health, UKZN, Durban, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| |
Collapse
|
9
|
Batidzirai JM, Manda SOM, Mwambi HG, Tanser F. Discrete Survival Time Constructions for Studying Marital Formation and Dissolution in Rural South Africa. Front Psychol 2020; 11:154. [PMID: 32132944 PMCID: PMC7040195 DOI: 10.3389/fpsyg.2020.00154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 01/21/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction: Marriage formation and dissolution are important life-course events which impact psychological well-being and health of adults and children experiencing the events. Family studies have usually concentrated on analyzing single transitions including Never Married to Married and Married to Divorced. This does not allow understanding and interrogation of dynamics of these life changing events and their effects on individuals and their families. The objective of this study was to assess determinants associated with transitions between and within marital states in South Africa. Methods: The population-based data available for this study consists of over 55, 000 subjects representing over 340, 000 person-years exposure from the Africa Health Research Institute (AHRI) in rural KwaZulu-Natal, South Africa. It was collected from 1 January 2004 to 31 December 2016. Multilevel multinomial, binary and competing risks regression models were used to model marital state occupation, transitions between marital states as well as investigate determinants of marital dissolution, respectively. Results: Between the years 2006 and 2007, a subject was more likely to be married than never married when compared to years 2004 − 2005. After 2007, subjects were less likely to be married than never married and the trend reduced over the years up to 2016 [with OR=0.86, CI=(0.78; 0.94), OR=0.71, CI=(0.64; 0.78), OR=0.60, CI=(0.54; 0.67), OR=0.50, CI=(0.44; 0.56), and OR = 0.43, CI = (0.38; 0.48)] for periods 2008 − 2009, 2010 − 2011, 2012 − 2013, 2014 − 2015, and 2016, respectively. In 2008 − 2009, subjects were more likely to experience a marital dissolution than in the period 2004 − 2005 and the trend slightly reduces from 2010 until 2013 [OR=24.49, CI=(5.53; 108.37)]. Raising age at first sexual debut was found to be inversely associated with a marital dissolution [OR = 0.97;CI = (0.95; 0.99)]. Highly educated subjects were more likely to stay in one marital state than those who never went to school [OR=6.43, CI=(4.89; 8.47), OR=18.86, CI=(1.14; 53.31), and OR=2.96, CI=(1.96; 4.46) for being married, separated and widowed, respectively, among subjects with tertiary education]. As the age at first marriage increased, subjects became less likely to experience a marital separation [OR = 0.06, CI = (0.00; 1.11), OR = 0.05, CI = (0.00; 0.91), and OR = 0.04, CI = (0.00; 0.76) for subjects who entered a first marriage at ages 18 − 22, 23 − 29, and 30 − 40, respectively]. Conclusion: The study found that marrying at later ages is associated with a lower rate of marital dissolution while more educated subjects tend to stay longer in one marital state. Sexual debut at later ages was associated with a lower likelihood of experiencing a marital dissolution. There could, however, be some factors that are not accounted for in the model that may lead to heterogeneity in these dynamics in our model specification which are captured by the random effects in the model. Nonetheless, we may postulate that existing programs that encourage delay in onset of sexual activity for HIV risk reduction for example, may also have a positive impact on lowering rates of marital dissolution, thus ultimately improving psychological and physical health.
Collapse
Affiliation(s)
- Jesca M Batidzirai
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Samuel O M Manda
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa.,Biostatistics Unit, South African Medical Research Council, Pretoria, South Africa.,Department of Statistics, University of Pretoria, Pretoria, South Africa
| | - Henry G Mwambi
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Frank Tanser
- Africa Health Research Institute, KwaZulu-Natal, South Africa.,Lincoln Institute for Health, University of Lincoln, Lincoln, United Kingdom.,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
10
|
Declines in HIV incidence among men and women in a South African population-based cohort. Nat Commun 2019; 10:5482. [PMID: 31792217 PMCID: PMC6889466 DOI: 10.1038/s41467-019-13473-y] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 11/08/2019] [Indexed: 12/15/2022] Open
Abstract
Over the past decade, there has been a massive scale-up of primary and secondary prevention services to reduce the population-wide incidence of HIV. However, the impact of these services on HIV incidence has not been demonstrated using a prospectively followed, population-based cohort from South Africa—the country with the world’s highest rate of new infections. To quantify HIV incidence trends in a hyperendemic population, we tested a cohort of 22,239 uninfected participants over 92,877 person-years of observation. We report a 43% decline in the overall incidence rate between 2012 and 2017, from 4.0 to 2.3 seroconversion events per 100 person-years. Men experienced an earlier and larger incidence decline than women (59% vs. 37% reduction), which is consistent with male circumcision scale-up and higher levels of female antiretroviral therapy coverage. Additional efforts are needed to get more men onto consistent, suppressive treatment so that new HIV infections can be reduced among women. Here, the authors investigate the outcome of prevention services scale-up on HIV incidence in a South African large population-based HIV surveillance cohort with over a decade of follow-up and associate a 43% reduction in incidence to earlier male medical circumcision and increased levels of antiretroviral therapy coverage.
Collapse
|
11
|
Space-time clustering of recently-diagnosed tuberculosis and impact of ART scale-up: Evidence from an HIV hyper-endemic rural South African population. Sci Rep 2019; 9:10724. [PMID: 31341191 PMCID: PMC6656755 DOI: 10.1038/s41598-019-46455-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/28/2019] [Indexed: 12/26/2022] Open
Abstract
In HIV hyperendemic sub-Saharan African communities, particularly in southern Africa, the likelihood of achieving the Sustainable Development Goal of ending the tuberculosis (TB) epidemic by 2030 is low, due to lack of cost-effective and practical interventions in population settings. We used one of Africa’s largest population-based prospective cohorts from rural KwaZulu-Natal Province, South Africa, to measure the spatial variations in the prevalence of recently-diagnosed TB disease, and to quantify the impact of community coverage of antiretroviral therapy (ART) on recently-diagnosed TB disease. We collected data on TB disease episodes from a population-based sample of 41,812 adult individuals between 2009 and 2015. Spatial clusters (‘hotspots’) of recently-diagnosed TB were identified using a space-time scan statistic. Multilevel logistic regression models were fitted to investigate the relationship between community ART coverage and recently-diagnosed TB. Spatial clusters of recently-diagnosed TB were identified in a region characterized by a high prevalence of HIV and population movement. Every percentage increase in ART coverage was associated with a 2% decrease in the odds of recently-diagnosed TB (aOR = 0.98, 95% CI:0.97–0.99). We identified for the first time the clear occurrence of recently-diagnosed TB hotspots, and quantified potential benefit of increased community ART coverage in lowering tuberculosis, highlighting the need to prioritize the expansion of such effective population interventions targeting high-risk areas.
Collapse
|
12
|
Dobra A, Bärnighausen T, Vandormael A, Tanser F. A method for statistical analysis of repeated residential movements to link human mobility and HIV acquisition. PLoS One 2019; 14:e0217284. [PMID: 31166973 PMCID: PMC6550382 DOI: 10.1371/journal.pone.0217284] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 05/08/2019] [Indexed: 12/05/2022] Open
Abstract
We propose a method for analyzing repeated residential movements based on graphical loglinear models. This method allows an explicit representation of residential presence and absence patterns from several areas without defining mobility measures. We make use of our method to analyze data from one of the most comprehensive demographic surveillance sites in Africa that is characterized by high adult HIV prevalence, high levels of poverty and unemployment and frequent residential changes. Between 2004 and 2016, residential changes were recorded for 8,857 men over 35,500.01 person-years, and for 12,158 women over 57,945.35 person-years. These individuals were HIV negative at baseline. Over the study duration, there were a total of 806 HIV seroconversions in men, and 2,458 HIV seroconversions in women. Our method indicates that establishing a residence outside the rural study area is a strong predictor of HIV seroconversion in men (OR = 2.003, 95% CI = [1.718,2.332]), but not in women. Residing inside the rural study area in a single or in multiple locations is a less significant risk factor for HIV acquisition in both men and women compared to moving outside the rural study area.
Collapse
Affiliation(s)
- Adrian Dobra
- Department of Statistics, University of Washington, Seattle, WA, United States of America
| | - Till Bärnighausen
- Heidelberg Institute of Global Health (HIGH), Medical Faculty and University Hospital, Heidelberg University, Heidelberg, Germany
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, United States of America
- Africa Health Research Institute,KwaZulu-Natal, South Africa
| | - Alain Vandormael
- Africa Health Research Institute,KwaZulu-Natal, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Frank Tanser
- Africa Health Research Institute,KwaZulu-Natal, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
- Research Department of Infection & Population Health, University College London, London, United Kingdom
| |
Collapse
|
13
|
Tanser F, Bärnighausen T, Dobra A, Sartorius B. Identifying 'corridors of HIV transmission' in a severely affected rural South African population: a case for a shift toward targeted prevention strategies. Int J Epidemiol 2019; 47:537-549. [PMID: 29300904 PMCID: PMC5913614 DOI: 10.1093/ije/dyx257] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2017] [Indexed: 11/24/2022] Open
Abstract
Background In the context of a severe generalized African HIV epidemic, the value of geographically targeted prevention interventions has only recently been given serious consideration. However, to date no study has performed a population-based analysis of the micro-geographical clustering of HIV incident infections, limiting the evidential support for such a strategy. Methods We followed 17 984 HIV-uninfected individuals aged 15–54 in a population-based cohort in rural KwaZulu-Natal, South Africa, and observed individual HIV sero-conversions between 2004 and 2014. We geo-located all individuals to an exact homestead of residence (accuracy <2 m). We then employed a two-dimensional Gaussian kernel of radius 3 km to produce robust estimates of HIV incidence which vary across continuous geographical space. We also applied Tango's flexibly shaped spatial scan statistic to identify irregularly shaped clusters of high HIV incidence. Results Between 2004 and 2014, we observed a total of 2 311 HIV sero-conversions over 70 534 person-years of observation, at an overall incidence of 3.3 [95% confidence interval (CI), 3.1-3.4] per 100 person-years. Three large irregularly-shaped clusters of new HIV infections (relative risk = 1.6, 1.7 and 2.3) were identified in two adjacent peri-urban communities near the National Road (P = 0.001, 0.015) as well as in a rural node bordering a recent coal mine development (P = 0.020), respectively. Together the clusters had a significantly higher age-sex standardized incidence of 5.1 (95% CI, 4.7-5.6) per 100 person-years compared with a standardized incidence of 3.0 per 100 person-years (95% CI, 2.9-3.2) in the remainder of the study area. Though these clusters comprise just 6.8% of the study area, they account for one out of every four sero-conversions observed over the study period. Conclusions Our study has revealed clear ‘corridors of transmission’ in this typical rural, hyper-endemic population. Even in a severely affected rural African population, an approach that seeks to provide preventive interventions to the most vulnerable geographies could be more effective and cost-effective in reducing the overall rate of new HIV infections. There is an urgent need to develop and test such interventions as part of an overall combination prevention approach.
Collapse
Affiliation(s)
- Frank Tanser
- Africa Health Research Institute, Durban, South Africa.,School of Nursing and Public Health, University of KwaZulu-Natal, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa.,Institute of Epidemiology and Health Care, University College London, London, UK
| | - Till Bärnighausen
- Africa Health Research Institute, Durban, South Africa.,Institute of Epidemiology and Health Care, University College London, London, UK.,Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Institute for Public Health, University of Heidelberg, Heidelberg, Germany
| | - Adrian Dobra
- Department of Statistics, Department of Biobehavioral Nursing and Health Informatics, Center for Statistics and the Social Sciences and Center for Studies in Demography and Ecology, University of Washington, Seattle, WA, USA
| | - Benn Sartorius
- School of Nursing and Public Health, University of KwaZulu-Natal, South Africa
| |
Collapse
|
14
|
TOMITA A, VANDORMAEL A, BÄRNIGHAUSEN T, PHILLIPS A, PILLAY D, DE OLIVEIRA T, TANSER F. Sociobehavioral and community predictors of unsuppressed HIV viral load: multilevel results from a hyperendemic rural South African population. AIDS 2019; 33:559-569. [PMID: 30702520 PMCID: PMC6547375 DOI: 10.1097/qad.0000000000002100] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Extensive antiretroviral therapy scale-up is expected to prevent onward transmission of HIV by reducing the overall community viral load. Despite multiple studies about predictors of detectable viral load derived from clinical setting, to date, no study has established such predictors using a population-based viral load survey in a sub-Saharan African hyperendemic setting to inform interventions designed to halt HIV transmission. We used one of Africa's largest prospective cohorts in rural KwaZulu-Natal Province, South Africa, to establish the key sociodemographic, behavioral and community predictors of unsuppressed viral load at the population level. METHODS We collected 5454 viral load measurements from a population-based viral load survey of 3892 women living with HIV from a rural population during 2011, 2013 and 2014. Multilevel logistic regression models were fitted to examine the risk predictors of unsuppressed viral load. RESULTS Among women living with HIV in this population, the prevalence of unsuppressed viral load was 69% in 2011, 58% in 2013 and 53% in 2014. Although time since HIV infection was associated with lower risk for virologic detection [adjusted odds ratio (aOR) = 0.91,0.87-0.94], young women (aOR = 2.59,1.47-4.55) with extensive external migration history (aOR = 1.25,1.02-1.54), greater number of sexual partners (aOR = 1.30,1.02-1.67), and longer history of residing in an HIV incidence hotspot community were more likely to experience unsuppressed viral load (aOR = 1.12,1.06-1.19). CONCLUSION Young women, number of sexual partners, transiency and longer residence in an HIV hotspot community are important determinants of unsuppressed viral load in a hyperendemic rural African setting. To substantially reduce the persistently high transmission potential in these settings, targeted interventions to address these risk factors will be essential for both individual and population health gains.
Collapse
Affiliation(s)
- Andrew TOMITA
- Africa Health Research Institute, Durban, South Africa
- KwaZulu-Natal Research Innovation and Sequencing (KRISP), Nelson R Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, South Africa
- Centre for Rural Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Alain VANDORMAEL
- Africa Health Research Institute, Durban, South Africa
- KwaZulu-Natal Research Innovation and Sequencing (KRISP), Nelson R Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Till BÄRNIGHAUSEN
- Africa Health Research Institute, Durban, South Africa
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, USA
- Heidelberg Institute for Public Health, University of Heidelberg, Heidelberg, Germany
| | - Andrew PHILLIPS
- Institute for Global Health, University College London, London, UK
| | - Deenan PILLAY
- Africa Health Research Institute, Durban, South Africa
- Division of Infection and Immunity, University College London, London, UK
| | - Tulio DE OLIVEIRA
- KwaZulu-Natal Research Innovation and Sequencing (KRISP), Nelson R Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, South Africa
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Frank TANSER
- Africa Health Research Institute, Durban, South Africa
- School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
- Research Department of Infection & Population Health, University College London, London, UK
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| |
Collapse
|
15
|
Dzomba A, Tomita A, Vandormael A, Govender K, Tanser F. Effect of ART scale-up and female migration intensity on risk of HIV acquisition: results from a population-based cohort in KwaZulu-Natal, South Africa. BMC Public Health 2019; 19:196. [PMID: 30764786 PMCID: PMC6376673 DOI: 10.1186/s12889-019-6494-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/29/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite increased antiretroviral therapy (ART) coverage, the incidence of HIV infection among women in rural South Africa remains high. While many socio-demographic and behavioral factors have been identified, the effect of female migration intensity on the risk of HIV acquisition before and after ART scale-up has not been evaluated in the country. METHODS We followed 13,315 female participants aged 15-49 who were HIV-uninfected at baseline and recorded their migration events between 2004 and 2015. Using a Cox proportional hazard model, we estimated the time to HIV acquisition among the women, adjusting for annual migration intensity (high: ≥2 events/year, moderate = 1 event/year, and low = 0 event/year) before and after ART scale-up in 2010. RESULTS 1998 (15%) new HIV-infection events were recorded during the observation period. Overall, high migration intensity was associated with an increased HIV acquisition risk among women when compared with low migration intensity (HR = 2.88, 95% CI: 1.56-5.53). Among those with high migration intensity, the risk of HIV acquisition was significantly lower in the post-ART period compared to the pre-ART period, after controlling for key socio-demographic and behavioural covariates (aHR = 0.18, 95% CI 0.04-0.83). CONCLUSIONS Women who migrated frequently after ART scale-up had a significantly reduced HIV acquisition risk compared to those before its implementation. While this reduction is encouraging, women who migrate frequently remain at high risk of HIV acquisition. In the era of ART, there remains a critical need for public health interventions to reduce the risk of HIV acquisition in this highly vulnerable population.
Collapse
Affiliation(s)
- Armstrong Dzomba
- Africa Health Research Institute (AHRI), KwaZulu-Natal, South Africa. .,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa. .,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban, South Africa.
| | - Andrew Tomita
- Africa Health Research Institute (AHRI), KwaZulu-Natal, South Africa.,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban, South Africa.,Centre for Rural Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Alain Vandormael
- Africa Health Research Institute (AHRI), KwaZulu-Natal, South Africa.,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa.,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban, South Africa
| | - Kaymarlin Govender
- Health Economics and HIV and AIDS Research Division (HEARD), University of KwaZulu-Natal, Durban, South Africa
| | - Frank Tanser
- Africa Health Research Institute (AHRI), KwaZulu-Natal, South Africa.,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa.,Research Department of Infection & Population Health, University College London, London, UK
| |
Collapse
|
16
|
Vandormael A, de Oliveira T, Tanser F, Bärnighausen T, Herbeck JT. High percentage of undiagnosed HIV cases within a hyperendemic South African community: a population-based study. J Epidemiol Community Health 2017; 72:168-172. [PMID: 29175867 DOI: 10.1136/jech-2017-209713] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/18/2017] [Accepted: 10/30/2017] [Indexed: 01/25/2023]
Abstract
BACKGROUND Undiagnosed HIV infections could undermine efforts to reverse the global AIDS epidemic by 2030. In this study, we estimated the percentage of HIV-positive persons who remain undiagnosed within a hyperendemic South African community. METHODS The data come from a population-based surveillance system located in the Umkhanyakude district of the northern KwaZulu-Natal province, South Africa. We annually tested 38 661 adults for HIV between 2005 and 2016. Using the HIV-positive test results of 12 039 (31%) participants, we then back-calculated the incidence of infection and derived the number of undiagnosed cases from this result. RESULTS The percentage of undiagnosed HIV cases decreased from 29.3% in 2005 to 15.8% in 2011. During this period, however, approximately 50% of the participants refused to test for HIV, which lengthened the average time from infection to diagnosis. Consequently, the percentage of undiagnosed HIV cases reversed direction and steadily increased from 16.1% to 18.9% over the 2012-2016 period. CONCLUSIONS Results from this hyperendemic South African setting show that the HIV testing rate is low, with long infection times, and an unsatisfactorily high percentage of undiagnosed cases. A high level of repeat HIV testing is needed to minimise the time from infection to diagnosis if the global AIDS epidemic is to be reversed within the next two decades.
Collapse
Affiliation(s)
- Alain Vandormael
- Africa Health Research Institute (AHRI), Durban, South Africa.,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa.,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, South Africa
| | - Tulio de Oliveira
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| | - Frank Tanser
- Africa Health Research Institute (AHRI), Durban, South Africa.,School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa.,Department of Infection and Population Health, Institute of Epidemiology and Health Care, University College London, London, UK
| | - Till Bärnighausen
- Africa Health Research Institute (AHRI), Durban, South Africa.,Department of Infection and Population Health, Institute of Epidemiology and Health Care, University College London, London, UK.,Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Massachusetts, USA.,Heidelberg Institute for Public Health, University of Heidelberg, Heidelberg, Germany
| | - Joshua T Herbeck
- International Clinical Research Center, Department of Global Health, University of Washington, Seattle, Washington, USA
| |
Collapse
|
17
|
Akullian A, Bershteyn A, Klein D, Vandormael A, Bärnighausen T, Tanser F. Sexual partnership age pairings and risk of HIV acquisition in rural South Africa. AIDS 2017; 31:1755-1764. [PMID: 28590328 PMCID: PMC5508850 DOI: 10.1097/qad.0000000000001553] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/16/2017] [Accepted: 05/23/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To quantify the contribution of specific sexual partner age groups to the risk of HIV acquisition in men and women in a hyperendemic region of South Africa. DESIGN We conducted a population-based cohort study among women (15-49 years of age) and men (15-55 years of age) between 2004 and 2015 in KwaZulu-Natal, South Africa. METHODS Generalized additive models were used to estimate smoothed HIV incidence rates across partnership age pairings in men and women. Cox proportional hazards regression was used to estimate the relative risk of HIV acquisition by partner age group. RESULTS A total of 882 HIV seroconversions were observed in 15 935 person-years for women, incidence rate = 5.5 per 100 person-years [95% confidence interval (CI), 5.2-5.9] and 270 HIV seroconversions were observed in 9372 person-years for men, incidence rate = 2.9 per 100 person-years (95% CI, 2.6-3.2). HIV incidence was highest among 15-24-year-old women reporting partnerships with 30-34-year-old men, incidence rate = 9.7 per 100 person-years (95% CI, 7.2-13.1). Risk of HIV acquisition in women was associated with male partners aged 25-29 years (adjusted hazard ratio; aHR = 1.44, 95% CI, 1.02-2.04) and 30-34 years (aHR = 1.50, 95% CI, 1.08-2.09) relative to male partners aged 35 and above. Risk of HIV acquisition in men was associated with 25-29-year-old (aHR = 1.72, 95% CI, 1.02-2.90) and 30-34-year-old women (aHR = 2.12, 95% CI, 1.03-4.39) compared to partnerships with women aged 15-19 years. CONCLUSION Age of sexual partner is a major risk factor for HIV acquisition in both men and women, independent of one's own age. Partner age pairings play a critical role in driving the cycle of HIV transmission.
Collapse
Affiliation(s)
- Adam Akullian
- Institute for Disease Modeling, Global Good Fund, Bellevue, Washington, USA
| | - Anna Bershteyn
- Institute for Disease Modeling, Global Good Fund, Bellevue, Washington, USA
| | - Daniel Klein
- Institute for Disease Modeling, Global Good Fund, Bellevue, Washington, USA
| | - Alain Vandormael
- Africa Health Research Institute, University of KwaZulu-Natal, Mtubatuba, South Africa
| | - Till Bärnighausen
- Africa Health Research Institute, University of KwaZulu-Natal, Mtubatuba, South Africa
- Institute for Public Health, Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Frank Tanser
- Department of Infection and Population Health, Institute of Epidemiology and Health Care, University College London, London, UK
| |
Collapse
|