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Skalland T, Ayles H, Bock P, Bwalya J, Shanaube K, Kasese N, Dupré M, Kosloff B, Floyd S, Wilson E, Moore A, Eshleman S, Fidler S, Hayes R, Donnell D. Community- and individual-level correlates of HIV incidence in HPTN 071 (PopART). J Int AIDS Soc 2023; 26:e26155. [PMID: 37643290 PMCID: PMC10465013 DOI: 10.1002/jia2.26155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
INTRODUCTION Universal HIV testing and treatment aims to identify all people living with HIV and offer them treatment, decreasing the number of individuals with unsuppressed HIV and thus reducing HIV transmission. Longitudinal follow-up of individuals with and without HIV in a cluster-randomized trial of communities allowed for the examination of community- and individual-level measures of HIV risk and HIV incidence. METHODS HPTN 071 (PopART) was a three-arm cluster-randomized trial conducted between 2013 and 2018 that evaluated the use of two combination HIV prevention strategies implemented at the community level to reduce HIV incidence compared to the standard of care. The trial, conducted in 21 communities in Zambia and South Africa, measured HIV incidence over 36 months in a population cohort of ∼2000 randomly selected adults per community aged 18-44. Multilevel models were used to assess the association between HIV incidence and community- and individual-level socio-demographic and behavioural risk factors, as well as prevalence of detectable virus (PDV) defined as the estimated proportion of the community with unsuppressed viral load. RESULTS Overall HIV incidence was 1.49/100 person-years. Communities with less financial wealth and communities with more individuals reporting having sex partners outside of the community or two or more sexual partners had higher HIV incidence. PDV at 2 years of study was 6.8% and was strongly associated with HIV incidence: for every 50% relative reduction in community PDV, there was a 49% (95% confidence interval [CI]: 37%-58%, p < 0.001) relative decrease in HIV incidence. At the individual level; socio-economic status, AUDIT score, medical male circumcision and certain sexual behaviours were associated with HIV risk. CONCLUSIONS Using data from the PopART randomized trial, we found several associations of HIV incidence with community-level measures reflecting the sexual behaviour and socio-economic make-up of each community. We also found a strong association between community PDV and HIV incidence supporting the use of PDV as a tool for monitoring progress in controlling the epidemic. Lastly, we found significant individual-level factors of HIV risk that are generally consistent with previous HIV epidemiological research. These results have the potential to identify high high-incidence communities, inform structural-level interventions, and optimize individual-level interventions for HIV prevention. CLINICAL TRIAL NUMBER ClinicalTrials.gov number, NCT01900977, HPTN 071 [PopArt].
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Affiliation(s)
| | - Helen Ayles
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Peter Bock
- Desmond Tutu TB CentreDepartment of Paediatrics and Child HealthFaculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Justin Bwalya
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Kwame Shanaube
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Nkatya Kasese
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Michelle Dupré
- Desmond Tutu TB CentreDepartment of Paediatrics and Child HealthFaculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Barry Kosloff
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Sian Floyd
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
| | - Ethan Wilson
- Fred Hutchinson Cancer CenterSeattleWashingtonUSA
| | | | - Susan Eshleman
- Johns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Sarah Fidler
- UK Department of Infectious DiseaseFaculty of Medicine, Imperial College NIHR BRCLondonUK
| | - Richard Hayes
- ZambartLusakaZambia
- London School of Hygiene and Tropical MedicineLondonUK
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Kenyon C. Variations in sexual network connectivity may explain dramatic variations in sexually transmitted infection prevalence between populations and over time: a selected four-country analysis. F1000Res 2022; 9:1009. [PMID: 36246487 PMCID: PMC9490289 DOI: 10.12688/f1000research.24968.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2022] [Indexed: 11/20/2022] Open
Abstract
Background: The incidence of sexually transmitted infections (STIs) has been noted to vary dramatically between population groups and over time. Here, the hypothesis that changes in network connectivity underpin these changes is explored. Methods: The incidence/prevalence estimates of HIV, herpes simplex virus-2, syphilis, chlamydia, and gonorrhoea, as well as two markers of sexual network connectivity (partner concurrency and multiple partnering) by ethnic group and sexual orientation in Kenya, South Africa, the United Kingdom (UK) and the United States (USA) were extracted from published studies. Pearson’s correlation was used to test the association between the markers of network connectivity and the incidence/prevalence of these five STIs. A literature review was performed to evaluate the possible causes of the increases and decreases in syphilis incidence over the past 60 years. Results: In each country, the five STIs were found to cluster in particular ethnic groups and sexual orientations and to be positively associated with the two markers of network connectivity. Syphilis incidence in the UK and USA was found to increase dramatically in the 1960s/1970s, decline in the 1980s and again increase in the late 1990s. These changes took place predominantly in men who have sex with men, and were preceded by corresponding changes in network connectivity. The large decline in antenatal syphilis prevalence in Kenya and South Africa in the 1990s were likewise preceded by declines in network connectivity. Conclusions: Although other explanatory variables are not controlled for, the present analysis is compatible with the hypothesis that differential network connectivity is a parsimonious explanation for variations in STI incidence over time and between populations.
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Affiliation(s)
- Chris Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Antwerp, 2000, Belgium
- Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, 7700, South Africa
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Mwale M, Muula AS. Effects of adolescent exposure to behaviour change interventions on their HIV risk reduction in Northern Malawi: a situation analysis. SAHARA J 2018; 15:146-154. [PMID: 30278823 PMCID: PMC6171447 DOI: 10.1080/17290376.2018.1529612] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding adolescents’ translation of HIV and AIDS-related behaviour change interventions (BCI) knowledge and skills into expected behavioural outcomes helps us appreciate behaviour change dynamics among young people and informs evidence-based programming. We explored the effects of adolescents’ exposure to BCI on their HIV risk reduction in selected schools in Nkhatabay and Mzimba districts and Mzuzu city in Northern Malawi. The study used questionnaires as instruments. Data were collected between January and April 2017. Adolescent boys and girls [n = 552], ages 11–19 were randomly sampled to participate. Data analysis was through multiple regression and content analysis. Respondents included 324 female [58.7%] and 228 male [41.3%]. Multiple regression analysis indicated that exposure to BCI did not affect risk reduction in the study area. The best stepwise model isolated sexual experience ([Beta = .727, p = .0001, p < .05]) as having the strongest correlation with the dependent variable – risk reduction. BCI exposure was stepwise excluded ([Beta = −.082, p = .053, p > .05]). There was therefore no evidence against the null hypothesis of no relationship between adolescent exposure to BCI and their HIV risk reduction. Overall there was limited BCI knowledge and skills translation to behavioural risk reduction. The study points to the need to evaluate and redesign adolescent BCI in line with current behavioural dynamics among young people in Malawi. The findings have been used to inform the design and programming of a model to be tested for feasibility through a quasi-experiment in the second phase of our project.
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Affiliation(s)
- M Mwale
- a Department of Public Health, School of Public Health and Family Medicine , University of Malawi College of Medicine , Blantyre , Malawi.,b Department of Education Foundations , Mzuzu University , Mzuzu , Malawi
| | - A S Muula
- a Department of Public Health, School of Public Health and Family Medicine , University of Malawi College of Medicine , Blantyre , Malawi.,c Africa Center of Excellence in Public Health and Herbal Medicine , University of Malawi , Zomba , Malawi
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Kenyon CR, Delva W. It's the network, stupid: a population's sexual network connectivity determines its STI prevalence. F1000Res 2018; 7:1880. [PMID: 30815252 PMCID: PMC6376253 DOI: 10.12688/f1000research.17148.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2018] [Indexed: 10/06/2023] Open
Abstract
There is little consensus as to why sexually transmitted infections (STIs), including HIV and bacterial vaginosis (BV) are more prevalent in some populations than others. Using a broad definition of sexual network connectivity that includes both structural and conductivity-related factors, we argue that the available evidence suggests that high prevalence of traditional STIs, HIV and BV can be parsimoniously explained by these populations having more connected sexual networks. Positive feedback, whereby BV and various STIs enhance the spread of other STIs, then further accentuates the spread of BV, HIV and other STIs. We review evidence that support this hypothesis and end by suggesting study designs that could further evaluate the hypothesis, as well as implications of this hypothesis for the prevention and management of STIs.
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Affiliation(s)
- Chris R. Kenyon
- Institute of Tropical Medicine, Antwerp, Antwerp, 2000, Belgium
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Wim Delva
- Department of Global Health, University of Stellenbosch, Stellenbosch, South Africa
- International Centre for Reproductive Health, Ghent University, Ghent, Belgium
- South African Centre for Epidemiological Modelling and Analysis, University of Stellenbosch, Stellenbosch, South Africa
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Kenyon CR, Buyze J, Schwartz IS. Strong association between higher-risk sex and HIV prevalence at the regional level: an ecological study of 27 sub-Saharan African countries. F1000Res 2018; 7:1879. [PMID: 30800288 PMCID: PMC6367661 DOI: 10.12688/f1000research.17108.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2018] [Indexed: 11/20/2022] Open
Abstract
Background: It is unclear why HIV prevalence varies by nearly two orders of magnitude between regions within countries in sub-Saharan Africa. In this ecological study, we assess if HIV prevalence by region is associated with any of four markers of higher risk sexual behavior: lifetime number of partners, multiple partners in past year, higher risk sex (defined as sex with non-cohabiting, non-marital partners) and age at debut. Methods: We performed Pearson's correlation between the 4 behavioral risk factors and HIV prevalence by region in 47 nationally representative surveys from 27 sub-Saharan African countries, separately by gender. In addition, principal components analysis was used to reduce the eight risk factors (four for each gender) to two principal components (PCs). Mixed effects linear regression was used to assess the relationship between the resulting two PCs and HIV prevalence after controlling for the prevalence of male circumcision. Results: HIV prevalence varied by a median 3.7 fold (IQR 2.9-7.9) between regions within countries. HIV prevalence was strongly associated with higher risk sex and, to a lesser extent, the other risk factors evaluated. Both PCs were strongly associated with HIV prevalence when assessed via linear regression. Conclusions: Differences in sexual behavior may underpin the large differences in HIV-prevalence between subpopulation within sub-Saharan African countries.
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Affiliation(s)
- Chris R Kenyon
- Clinical Science, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | - Jozefien Buyze
- Clinical Science, Institute of Tropical Medicine, Antwerp, 2000, Belgium
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Kenyon CR, Delva W. It's the network, stupid: a population's sexual network connectivity determines its STI prevalence. F1000Res 2018; 7:1880. [PMID: 30815252 PMCID: PMC6376253 DOI: 10.12688/f1000research.17148.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/23/2019] [Indexed: 11/20/2022] Open
Abstract
There is little consensus as to why sexually transmitted infections (STIs), including HIV and bacterial vaginosis (BV) are more prevalent in some populations than others. Using a broad definition of sexual network connectivity that includes both structural and conductivity-related factors, we argue that the available evidence suggests that high prevalence of traditional STIs, HIV and BV can be parsimoniously explained by these populations having more connected sexual networks. Positive feedback, whereby BV and various STIs enhance the spread of other STIs, then further accentuates the spread of BV, HIV and other STIs. We review evidence that support this hypothesis and end by suggesting study designs that could further evaluate the hypothesis, as well as implications of this hypothesis for the prevention and management of STIs.
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Affiliation(s)
- Chris R. Kenyon
- Institute of Tropical Medicine, Antwerp, Antwerp, 2000, Belgium
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Wim Delva
- Department of Global Health, University of Stellenbosch, Stellenbosch, South Africa
- International Centre for Reproductive Health, Ghent University, Ghent, Belgium
- South African Centre for Epidemiological Modelling and Analysis, University of Stellenbosch, Stellenbosch, South Africa
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Kenyon CR, Wolfs K, Osbak K, Malataliana M, Van Hal G, Zondo S, van Lankveld J. Could differences in implicit attitudes to sexual concurrency play a role in generalized HIV epidemics? F1000Res 2018; 7:608. [PMID: 30450199 PMCID: PMC6221060 DOI: 10.12688/f1000research.14951.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/11/2018] [Indexed: 10/05/2023] Open
Abstract
Background: Sexual partner concurrency has been implicated in the genesis of generalized HIV epidemic in South Africa. Most South Africans, however, disapprove of concurrency in surveys. These surveys test individuals' explicit attitudes which are susceptible to a number of important biases such as the social desirability bias. Assessment of implicit cognitions have been found to be better predictors of behaviour in socially sensitive domains. We hypothesized that South Africans may have implicit attitudes more tolerant of concurrency than lower concurrency prevalence populations. Methods: To test this hypothesis, we developed a concurrency-implicit association test (C-IAT) and compared the C-IATs of samples of South African and Belgian university students. Results: We found a large and statistically significant difference in the C-IAT between the South Africans (D600-score = -0.009, indicating absence of preference for concurrency or monogamy) and Belgians (D600-score = 0.783, indicating a strong preference for monogamy; t-test = 13.3; P < 0.0001). The effect size measure, Cohen's d, was found to be 0.88, which is considered a large effect size in this field. Conclusions: Our results are compatible with the thesis that differences in implicit attitudes to concurrency play a role in the genesis of generalised HIV epidemics.
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Affiliation(s)
- Chris R. Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | - Kenny Wolfs
- Faculty of Psychology and Educational Science, Open University of the Netherlands, Heerlen, The Netherlands
| | - Kara Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | | | - Guido Van Hal
- Medical Sociology and Health Policy, University of Antwerp, Antwerp, Belgium
| | - Sizwe Zondo
- Department of Psychology, Rhodes University, Grahamstown, South Africa
| | - Jacques van Lankveld
- Faculty of Psychology and Educational Science, Open University of the Netherlands, Heerlen, The Netherlands
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Kenyon CR, Wolfs K, Osbak K, Malataliana M, Van Hal G, Zondo S, van Lankveld J. Could differences in implicit attitudes to sexual concurrency play a role in generalized HIV epidemics? F1000Res 2018; 7:608. [PMID: 30450199 PMCID: PMC6221060 DOI: 10.12688/f1000research.14951.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2018] [Indexed: 11/22/2022] Open
Abstract
Background: Sexual partner concurrency has been implicated in the genesis of generalized HIV epidemic in South Africa. Most South Africans, however, disapprove of concurrency in surveys. These surveys test individuals' explicit attitudes which are susceptible to a number of important biases such as the social desirability bias. Assessment of implicit cognitions have been found to be better predictors of behaviour in socially sensitive domains. We hypothesized that South Africans may have implicit attitudes more tolerant of concurrency than lower concurrency prevalence populations. Methods: To test this hypothesis, we developed a concurrency-implicit association test (C-IAT) and compared the C-IATs of samples of South African and Belgian university students. Results: We found a large and statistically significant difference in the C-IAT between the South Africans (D600-score = -0.009, indicating absence of preference for concurrency or monogamy) and Belgians (D600-score = 0.783, indicating a strong preference for monogamy; t-test = 13.3; P < 0.0001). The effect size measure, Cohen's d, was found to be 0.88, which is considered a large effect size in this field. Conclusions: Our results are compatible with the thesis that differences in implicit attitudes to concurrency play a role in the genesis of generalised HIV epidemics.
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Affiliation(s)
- Chris R. Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | - Kenny Wolfs
- Faculty of Psychology and Educational Science, Open University of the Netherlands, Heerlen, The Netherlands
| | - Kara Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | | | - Guido Van Hal
- Medical Sociology and Health Policy, University of Antwerp, Antwerp, Belgium
| | - Sizwe Zondo
- Department of Psychology, Rhodes University, Grahamstown, South Africa
| | - Jacques van Lankveld
- Faculty of Psychology and Educational Science, Open University of the Netherlands, Heerlen, The Netherlands
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HIV prevalence by ethnic group covaries with prevalence of herpes simplex virus-2 and high-risk sex in Uganda: An ecological study. PLoS One 2018; 13:e0195431. [PMID: 29617423 PMCID: PMC5884562 DOI: 10.1371/journal.pone.0195431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 03/22/2018] [Indexed: 11/19/2022] Open
Abstract
Background HIV prevalence varies from 1.7% to 14.8% between ethnic groups in Uganda. Understanding the factors responsible for this heterogeneity in HIV spread may guide prevention efforts. Methods We evaluated the relationship between HIV prevalence by ethnic group and a range of risk factors as well as the prevalence of herpes simplex virus-2 (HSV-2), syphilis and symptomatic STIs in the 2004/2005 Uganda HIV/AIDS Sero-Behavioural Survey—a two stage, nationally representative, population based survey of 15–59-year-olds. Spearman’s correlation was used to assess the relationship between HIV prevalence and each variable. Results There was a positive association between HIV prevalence and HSV-2, symptomatic STIs and high-risk sex (sex with a non-cohabiting, non-marital partner) for women. Non-significant positive associations were present between HIV and high-risk sex for men and lifetime number of partners for men and women. Conclusion Variation in sexual behavior may contribute to the variations in HIV, HSV-2 and other STI prevalence by ethnic group in Uganda. Further work is necessary to delineate which combinations of risk factors determine differential STI spread in Uganda.
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We should monitor the population-level effects of preexposure prophylaxis. AIDS 2017; 31:459-460. [PMID: 28079546 DOI: 10.1097/qad.0000000000001356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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