Evaluation of the accuracy of the Asanté assay as a point-of-care rapid test for HIV-1 recent infections using serum bank specimens from blood donors in South Africa, July 2018 - August 2021.

BACKGROUND: Point-of-care (POC) rapid recency testing can be used as a cost-effective tool to identify recently infected individuals (i.e. infected within the last 12 months) in near-real time, support epidemic control and identify hotspots for transmission as part of recent infection surveillance. OBJECTIVE: To evaluate the performance of the Asanté (HIV-1) rapid recency assay as a POC rapid test among blood donors in South Africa (SA). METHODS: The study was a cross-sectional and validity study of the Asanté HIV-1 Rapid Recency Assay performed on 715 consecutively archived plasma donor specimens from the SA National Blood Services to determine their recency and established HIV infection status. ELISA and rapid assays for HIV antibody detection were used as the reference-testing standard for confirming an infection, while the Maxim HIV-1 limiting antigen (LAg) avidity assay was used as a reference for comparing HIV recency status. Validity tests (sensitivity, specificity, negative and positive predictive values) and Cohen-Kappa tests of the agreement were conducted to compare the Asanté HIV-1 rapid recency assay results with the reference tests. RESULTS: Of the 715 studied blood samples, 63.1% (n=451/715) were confirmed to be HIV-positive based on the reference standard. The sensitivity and specificity of the Asanté HIV-1 rapid recency assay in diagnosing established HIV infection compared to the ELISA were 98.4% (95% CI 96.7 - 99.3) and 99.6% (95% CI 97.6 - 100), respectively. Compared with HIV rapid assay, the sensitivity and specificity of the Asanté HIV-1 rapid recency assay was 98.7% (95% CI 97.0 - 99.4) and 99.2% (95% CI 97.1 - 100), respectively. Of the 451 HIV-positive blood samples, 43% were confirmed as recent HIV infections by the Maxim HIV-1 LAg avidity assay. There was high agreement between the Asanté HIV-1 rapid recency assay and the Maxim HIV-1 LAg avidity assay (94.1%, k=0.879, p<0.0001). The sensitivity and specificity of the Asante HIV-1 assay was 89.4% (95% CI 84.0 - 93.0) and 97.7% (95% CI 94.8 - 99.0), respectively. CONCLUSION: The Asanté HIV-1 rapid recency assay test results demonstrated high accuracy (>90%) compared with the HIV ELISA and rapid assays for determining established infection and the Maxim HIV-1 LAg avidity assay for classifying recent HIV-1 infections. The assay's sensitivity for established infections was below the World Health Organization criteria (<99%) for POC devices. The Asanté HIV-1 rapid recency assay can be used to distinguish between recent and long-term infections, but may not be considered a POC test for determining HIV infection.

Leveraging epidemiology as a decision support tool during the COVID-19 epidemic in South Africa.

By May 2021, South Africa (SA) had experienced two 'waves' of COVID-19 infections, with an initial peak of infections reached in July 2020, followed by a larger peak of infections in January 2021. Public health decisions rely on accurate and timely disease surveillance and epidemiological analyses, and accessibility of data at all levels of government is critical to inform stakeholders to respond effectively. In this paper, we describe the adaptation, development and operation of epidemiological surveillance and modelling systems in SA in response to the COVID-19 epidemic, including data systems for monitoring laboratory-confirmed COVID-19 cases, hospitalisations, mortality and recoveries at a national and provincial level, and how these systems were used to inform modelling projections and public health decisions. Detailed descriptions on the characteristics and completeness of individual datasets are not provided in this paper. Rapid development of robust data systems was necessary to support the response to the SA COVID-19 epidemic. These systems produced data streams that were used in decision-making at all levels of government. While much progress was made in producing epidemiological data, challenges remain to be overcome to address gaps to better prepare for future waves of COVID-19 and other health emergencies.

Recency of HIV infection, antiretroviral therapy use and viral loads among symptomatic sexually transmitted infection service attendees in South Africa.

BACKGROUND: Better integration of HIV and sexually transmitted infection (STI) prevention and treatment services is needed to accelerate progress towards the goal of zero new HIV infections. OBJECTIVES: To describe HIV positivity, antiretroviral therapy (ART) use, viral suppression and recency of HIV infection among symptomatic STI service attendees at two primary care clinics in South Africa. METHODS: In a cross-sectional study, male and female STI service attendees presenting with symptoms consistent with STI syndromes were enrolled following informed consent. An interviewer-administered questionnaire was completed and appropriate genital and blood specimens were collected for STI testing and HIV biomarker measurements including recency of infection and antiretroviral (ARV) drug levels. Descriptive statistics were used to describe enrolled attendees, and to determine the proportion of attendees who were HIV-positive, recently infected, taking ART and virally suppressed. HIV-positive attendees with detectable ARVs were considered to be on ART, while those with viral loads (VLs) ≤200 copies/mL were considered virally suppressed. RESULTS: Of 451 symptomatic attendees whose data were analysed, 93 (20.6%) were HIV-positive, with 15/93 (16.1%) being recently infected. Recent infection was independently associated with genital ulcer disease at presentation, especially ulcers with no detectable STI pathogens. Among the 78 (83.9%) with long-term infection, only 30 (38.5%) were on ART, with 23/30 (76.7%) virally suppressed. CONCLUSIONS: In a population at risk of HIV transmission, there was a high burden of recent infection and unsuppressed VLs. Incorporating pre-exposure prophylaxis, ART initiation and adherence support into STI services will be necessary for progress towards eliminating HIV transmission.

Recency of HIV infection, antiretroviral therapy use and viral loads among symptomatic sexually transmitted infection service attendees in South Africa

Background. Better integration of HIV and sexually transmitted infection (STI) prevention and treatment services is needed to accelerate progress towards the goal of zero new HIV infections. Objectives. To describe HIV positivity, antiretroviral therapy (ART) use, viral suppression and recency of HIV infection among symptomatic STI service attendees at two primary care clinics in South Africa. Methods. In a cross-sectional study, male and female STI service attendees presenting with symptoms consistent with STI syndromes were enrolled following informed consent. An interviewer-administered questionnaire was completed and appropriate genital and blood specimens were collected for STI testing and HIV biomarker measurements including recency of infection and antiretroviral (ARV) drug levels. Descriptive statistics were used to describe enrolled attendees, and to determine the proportion of attendees who were HIV-positive, recently infected, taking ART and virally suppressed. HIV-positive attendees with detectable ARVs were considered to be on ART, while those with viral loads (VLs) ≤200 copies/mL were considered virally suppressed. Results. Of 451 symptomatic attendees whose data were analysed, 93 (20.6%) were HIV-positive, with 15/93 (16.1%) being recently infected. Recent infection was independently associated with genital ulcer disease at presentation, especially ulcers with no detectable STI pathogens. Among the 78 (83.9%) with long-term infection, only 30 (38.5%) were on ART, with 23/30 (76.7%) virally suppressed. Conclusions. In a population at risk of HIV transmission, there was a high burden of recent infection and unsuppressed VLs. Incorporating pre-exposure prophylaxis, ART initiation and adherence support into STI services will be necessary for progress towards eliminating HIV transmission

HIV care coverage among HIV-positive adolescent girls and young women in South Africa: Results from the HERStory Study.

BACKGROUND: Health service coverage cascades measure the proportion of a population in need of a service that experienced a positive health outcome from the service, and enable tracking of progress in achieving universal health coverage and inequities in care coverage. OBJECTIVES: To investigate HIV care coverage among HIV-positive adolescent girls and young women (AGYW) living in six South African districts, compare coverage by age and socioeconomic status (SES), and investigate other associated factors including participation in a combination HIV prevention intervention. METHODS: The HERStory Study was an evaluation of the combination intervention, comprising a representative household survey of AGYW aged 15 - 24 years living in six intervention districts. From September 2017 to November 2018, biological, sociodemographic and behavioural data were collected. HIV-positive status, initiation of antiretroviral therapy (ART) and viral suppression were determined through laboratory tests (enzyme-linked immunosorbent assay for HIV antibodies, antiretroviral (ARV) metabolites and viral load (VL) testing). Viral suppression was defined as a VL <1 000 copies/mL. Knowledge of HIV-positive status was self-reported, and participants testing positive for ARV metabolites were assumed to have known their HIV-positive status. Unconditional HIV care cascades were created, stratified by age and SES. We used Pearson's χ2 tests corrected for survey-based analysis to describe factors associated with knowledge of HIV status, and being on ART. RESULTS: Of the 4 399 participants, 568 were HIV-positive (12.4%), of whom 60.8% (95% confidence interval (CI) 57.1 - 64.5) knew their status, 50.6% (95% CI 46.6 - 54.0) were on ART, and 62.1% (95% CI 58.4 - 65.9) were virally suppressed. Most participants (84.9%) were in the lower SES group, and they had better coverage than the higher SES group: 61.9% (95% CI 58.3 - 65.4) knew their status, 52.1% (95% CI 48.4 - 55.9) were on ART, and 64.9% (95% CI 61.3 - 68.4) were virally suppressed, compared with 55.0% (95% CI 42.1 - 68.0), 40.0% (95% CI 29.2 - 50.8), and 46.6% (95% CI 34.5 - 58.7), respectively. Participants aged 15 - 19 years had slightly inferior coverage to the 20 - 24-year-old group: 57.5% knew their status, 46.1% were on ART and 59.5% were virally suppressed, compared with 62.3%, 52.2% and 63.3%. CONCLUSIONS: These findings emphasise the need to close the gaps in HIV care coverage among AGYW, of whom only 61% knew their HIV-positive status and only 62% were virally suppressed. There is pro-poor inequality in HIV care coverage, with those in lower socioeconomic groups more likely to be virally suppressed.

Hepatitis C genotype distribution in patient and blood donor samples in South Africa for the period 2008-2012.

There are limited molecular epidemiological studies of hepatitis C at a national level in South Africa. The introduction of newer treatment modalities for hepatitis C requires knowledge of the genotypes as these may have different prognostic and therapeutic implications. This retrospective study describes genotype distributions of patients attending specialist clinics and a blood donor group studied during the period 2008-2012 in South Africa. Residual samples from diagnostic viral load testing from specialist clinics in South Africa (n=941) and from the South African National Blood Service (n=294) were analysed quantitatively by real-time PCR and genotyped using the Versant line probe assay or sequencing. Genotype 1 was predominant in blood donors (34%), whilst genotype 5a was prevalent in patients (36%). In the blood donor group, genotype 4 was detected for the first time. Genotype 2 was rare in the patient group and not detected in blood donors. Genotype 1 was the predominant genotype in the younger age groups (less than 30 years), whereas genotype 5a was found at higher proportions in the older age groups for both the patient and blood donor groups, comprising more than 60% of genotypes in those older than 50 years. Genotypes 1 and 5 were at highest proportions across all provinces compared to other genotypes. In blood donors, genotype 1 was predominant among Caucasians (43%) and genotype 5a among Blacks (54%). Such information is required for planning the impact on the health sector with regard to newly emerging therapies for hepatitis C and burden of disease.

Naturally occurring resistance mutations within the core and NS5B regions in hepatitis C genotypes, particularly genotype 5a, in South Africa.

Approximately 1 million South Africans are infected with Hepatitis C virus (HCV). The standard of care (SOC) in South Africa is combination therapy (pegylated interferon and ribavirin). HCV genotypes and/or mutations in the core/non-structural regions have been associated with response to therapy and/or disease progression. This study examines mutations in the core (29-280 amino acids, including ∼ 90 E1 amino acids) and NS5B (241-306 amino acids) regions on pre-treatment isolates from patients attending Johannesburg hospitals or asymptomatic South African blood donors. Diversity within known CD4+ and CD8+ T-cell epitopes was also explored. Samples grouped into subtypes 1a(N = 10) 1b(N = 12), 3a(N = 5), 4a(N = 3) and 5a(N = 61). Two mutations, associated with interferon resistance-R70Q and T110N-were present in 29 genotype 5a core sequences. No resistance mutation to NS5B nucleotide inhibitors, sofosbuvir was found. Six putative CD8+ and one CD4+ T-cell epitope sequence in the core region showed binding scores of <300 IC50nM to HLA alleles frequently observed in the South African population. No known CD8+ and CD4+ T-cell epitopes were mapped in the NS5B region. The analysis begs the question whether those infected with genotype 5a will benefit better on interferon-free combination therapies. This study provides new insight into one of the lesser studied HCV genotypes and compares the diversity seen in a large pre-treatment cohort with other subtypes.

Frequencies of immune hypersensitivity reaction-associated HLA class I alleles in healthy South African Indian and mixed ancestry populations determined by a novel real-time PCR assay.

We have determined the frequencies of human leucocyte antigen (HLA)-B*57:01, HLA-B*35:05, HLA-C*04 and HLA-C*08 in healthy individuals of South African Indian (SAI) ethnicity (n = 50) and South African mixed (SAM) ancestry (n = 50) using real-time allele-specific polymerase chain reaction (AS-PCR) assay. HLA-B*57:01 associates with immune hypersensitivity reaction (IHR) in individuals exposed to abacavir (ABC), while nevirapine (NVP) IHR associates with HLA-B*35:05, HLA-C*04 and HLA-C*08. Real-time AS-PCR assays typically use less DNA, are more cost-effective and rapid compared with conventional genotyping methods, such as sequence-based typing (SBT). The assay was developed using samples of known HLA class I genotype and subsequently applied to the SAI and SAM samples. HLA-B*57:01 was detected in SAM and SAI populations at frequencies of 8.0% and 12.0%, respectively, while HLA-B*35:05 was not found in SAI individuals, but was present in 6.0% of SAM individuals. HLA-C*04 was detected in 22.0% and 24.0% of SAM and SAI individuals, respectively, while 10.0% and 8.0% of SAM and SAI individuals, respectively, were HLA-C*08 positive. This study reports the development of a novel real-time AS-PCR assay to identify HLA class I alleles associated with ABC and NVP IHR and has established the frequencies of these alleles present in healthy SAI and SAM populations. Using South African demographic data, our hypothetical analysis suggests that a substantial number of individuals would benefit from the assay.

Identifying high-risk areas for sporadic measles outbreaks: lessons from South Africa.

OBJECTIVE: To develop a model for identifying areas at high risk for sporadic measles outbreaks based on an analysis of factors associated with a national outbreak in South Africa between 2009 and 2011. METHODS: Data on cases occurring before and during the national outbreak were obtained from the South African measles surveillance programme, and data on measles immunization and population size, from the District Health Information System. A Bayesian hierarchical Poisson model was used to investigate the association between the risk of measles in infants in a district and first-dose vaccination coverage, population density, background prevalence of human immunodeficiency virus (HIV) infection and expected failure of seroconversion. Model projections were used to identify emerging high-risk areas in 2012. FINDINGS: A clear spatial pattern of high-risk areas was noted, with many interconnected (i.e. neighbouring) areas. An increased risk of measles outbreak was significantly associated with both the preceding build-up of a susceptible population and population density. The risk was also elevated when more than 20% of infants in a populous area had missed a first vaccine dose. The model was able to identify areas at high risk of experiencing a measles outbreak in 2012 and where additional preventive measures could be undertaken. CONCLUSION: The South African measles outbreak was associated with the build-up of a susceptible population (owing to poor vaccine coverage), high prevalence of HIV infection and high population density. The predictive model developed could be applied to other settings susceptible to sporadic outbreaks of measles and other vaccine-preventable diseases.

Implications of spatially heterogeneous vaccination coverage for the risk of congenital rubella syndrome in South Africa.

Rubella is generally a mild childhood disease, but infection during early pregnancy may cause spontaneous abortion or congenital rubella syndrome (CRS), which may entail a variety of birth defects. Since vaccination at levels short of those necessary to achieve eradication may increase the average age of infection, and thus potentially the CRS burden, introduction of the vaccine has been limited to contexts where coverage is high. Recent work suggests that spatial heterogeneity in coverage should also be a focus of concern. Here, we use a detailed dataset from South Africa to explore the implications of heterogeneous vaccination for the burden of CRS, introducing realistic vaccination scenarios based on reported levels of measles vaccine coverage. Our results highlight the potential impact of country-wide reductions of incidence of rubella on the local CRS burdens in districts with small population sizes. However, simulations indicate that if rubella vaccination is introduced with coverage reflecting current estimates for measles coverage in South Africa, the burden of CRS is likely to be reduced overall over a 30 year time horizon by a factor of 3, despite the fact that this coverage is lower than the traditional 80 per cent rule of thumb for vaccine introduction, probably owing to a combination of relatively low birth and transmission rates. We conclude by discussing the likely impact of private-sector vaccination.

Surveillance of transmitted HIV-1 drug resistance in Gauteng and KwaZulu-Natal Provinces, South Africa, 2005-2009.

Surveillance of human immunodeficiency virus type 1 transmitted drug resistance (TDR) was conducted among pregnant women in South Africa over a 5-year period after the initiation of a large national antiretroviral treatment program. Analysis of TDR data from 9 surveys conducted between 2005 and 2009 in 2 provinces of South Africa suggests that while TDR remains low (<5%) in Gauteng Province, it may be increasing in KwaZulu-Natal, with the most recent survey showing moderate (5%-15%) levels of resistance to the nonnucleoside reverse transcriptase inhibitor drug class.

Palindromic-nucleotide substitutions (PNS) of hepatitis C virus genotypes 1 and 5a from South Africa.

The HCV stem-loop subdomains III-a, -b and -c have been shown to reflect the characteristics of the virus and identify isolates by genus, genotype and subtype. The aim of this study was to investigate the genotype-specific PNS within the 5'UTR of prevalent HCV genotypes (1 and 5a) found in South Africa. The genotype 5a (N = 35) and genotype 1 sequences (N=20) were from patients presenting with liver disease or haemophilia, respectively. PNS HCV typing characteristics, defined previously, were observed. The PNS method differentiated subtypes 1a and 1c from subtype 1b by the base change at nucleotide position 243. A lack of structural data from the variable loci V1 of the 5'UTR did not allow us to further differentiate the subtypes of 1. A nucleotide change from a thymine (T) to a cytosine (C) at position 183 was found among genotype 5a sequences. This mutation changed the stable U-AA bond to a Y AA bulge at base-pair position 32. There was an insertion of a single adenine (A) at position 207. At present PNS analysis is labour intensive but, with development of further software to aid the computer analysis, it has the potential to provide a rapid, reliable alternative to phylogenetic analysis.

Acute HIV infections among men with genital ulcer disease in South Africa.

We investigated acute human immunodeficiency virus (HIV) infection among men enrolled in a genital ulcer treatment trial in South Africa. HIV-negative participants were tested at baseline by HIV RNA polymerase chain reaction and followed up after 1 month to measure HIV seroconversion. There were 228 HIV-negative men at baseline; 10 were positive for HIV RNA, and 8 seroconverted to HIV at day 28. The prevalence of acute HIV among HIV-negative men at baseline was 18 (7.9%) of 228 men (95% confidence interval [CI], 4.4-11.4) and 18 (2.9%) of 615 men (95% CI, 1.6-4.3) in the overall study population. These data highlight the importance of genital ulcer patients in HIV transmission. Trial Registration. ClinicalTrials.gov identifier: NCT00164424 .

Interim report on pandemic H1N1 influenza virus infections in South Africa, April to October 2009: epidemiology and factors associated with fatal cases.

We provide an interim report on pandemic H1N1 influenza activity in South Africa, with a focus on the epidemiology and factors associated with deaths. Following the importation of the virus on 14 July 2009, and the epidemic peak during the week starting 3 August, the incidence in South Africa has declined. A total of 12,331 cases and 91 deaths have been laboratory-confirmed as of 12 October 2009. Age distribution and risk groups were similar to those observed elsewhere. The median age of patients who died (33.5 years) was significantly higher than that of the non-fatal cases (15.0 years, p<0.01). The most common underlying conditions among fatal cases were infection with human immunodeficiency virus (17/32 tested) and pregnancy (25/45 women of reproductive age). Active tuberculosis coinfection was present in seven of 72 fatal cases. These findings should be taken into consideration when planning vaccination strategies for 2010.

Poor sensitivity of field rapid HIV testing: implications for mother-to-child transmission programme.

We validated rapid HIV tests among pregnant women in a clinical setting. Field testing was performed using First Response 1,2,3 or Standard Diagnostic and Pareekshak tests. Results were confirmed by third generation HIV ELISA. Discordant or negative, specimens were confirmed by RNA PCR and a fourth generation ELISA test. Sensitivity and specificity were 94.5% (CI: 85.8-98.2) and 100% for First Response; 87.5% (CI: 46.7-99.3) and 100% (CI: 87.7-100%) for Standard Diagnostic and 90.2% (CI: 81.2-95.4) and 100% (CI: 98-100%) for Pareekshak. These sensitivities were lower than laboratory validation which approached 100%. The low-field sensitivity results have implications for Prevention of Mother-to-Child Transmission services.

Male circumcision and Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis: observations after a randomised controlled trial for HIV prevention.

OBJECTIVE: To assess the association between male circumcision and Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis using data from a male circumcision randomised controlled trial. METHODS: We used data collected during the male circumcision trial conducted in Orange Farm (South Africa) among men aged 18-24 years. Altogether, 1767 urine samples collected during the final follow-up visit were analysed using PCR. Prevalence of N gonorrhoeae, C trachomatis and T vaginalis was assessed as a function of male circumcision using odds ratios (OR) given by univariate and multivariate logistic regression. RESULTS: In an intention-to-treat analysis, prevalence of N gonorrhoeae, C trachomatis and T vaginalis among intervention and control groups were 10.0% versus 10.3% (OR 0.97; p = 0.84), 2.1% versus 3.6% (OR 0.58; p = 0.065) and 1.7% versus 3.1% (OR 0.54; p = 0.062), respectively. The association between T vaginalis and male circumcision remained borderline when controlling for age, ethnic group, number of lifetime partners, marital status, condom use and HIV status (AOR 0.48; p = 0.069). In the as-treated analysis, this association became significant (OR 0.49, p = 0.030; AOR 0.41, p = 0.030). CONCLUSIONS: This study demonstrates for the first time that male circumcision reduces T vaginalis infection among men. This finding explains why women with circumcised partners are less at risk for T vaginalis infection than other women. The protective effect on T vaginalis is an additional argument to recommend male circumcision in Africa where it is acceptable.

Impact of stepping stones on incidence of HIV and HSV-2 and sexual behaviour in rural South Africa: cluster randomised controlled trial.

OBJECTIVE: To assess the impact of Stepping Stones, a HIV prevention programme, on incidence of HIV and herpes simplex type 2 (HSV-2) and sexual behaviour. DESIGN: Cluster randomised controlled trial. SETTING: 70 villages (clusters) in the Eastern Cape province of South Africa. PARTICIPANTS: 1360 men and 1416 women aged 15-26 years, who were mostly attending schools. INTERVENTION: Stepping Stones, a 50 hour programme, aims to improve sexual health by using participatory learning approaches to build knowledge, risk awareness, and communication skills and to stimulate critical reflection. Villages were randomised to receive either this or a three hour intervention on HIV and safer sex. Interviewers administered questionnaires at baseline and 12 and 24 months and blood was tested for HIV and HSV-2. PRIMARY OUTCOME MEASURE: incidence of HIV. Other outcomes: incidence of HSV-2, unwanted pregnancy, reported sexual practices, depression, and substance misuse. RESULTS: There was no evidence that Stepping Stones lowered the incidence of HIV (adjusted incidence rate ratio 0.95, 95% confidence interval 0.67 to 1.35). The programme was associated with a reduction of about 33% in the incidence of HSV-2 (0.67, 0.46 to 0.97; P=0.036)-that is, Stepping Stones reduced the number of new HSV-2 infections over a two year period by 34.9 (1.6 to 68.2) per 1000 people exposed. Stepping Stones significantly improved a number of reported risk behaviours in men, with a lower proportion of men reporting perpetration of intimate partner violence across two years of follow-up and less transactional sex and problem drinking at 12 months. In women desired behaviour changes were not reported and those in the Stepping Stones programme reported more transactional sex at 12 months. CONCLUSION: Stepping Stones did not reduce incidence of HIV but had an impact on several risk factors for HIV-notably, HSV-2 and perpetration of intimate partner violence. TRIAL REGISTRATION: Clinical Trials NCT00332878.

Factors associated with HIV sero-positivity in young, rural South African men.

OBJECTIVE: To describe factors associated with HIV infection in men aged 15-26 years. SETTING: Rural Eastern Cape Province, South Africa. SAMPLE: A total of 1277 sexually experienced Xhosa male volunteers from 70 villages participating in a cluster randomized controlled trial of an HIV behavioural intervention. Xhosas circumcise during manhood initiation rituals. DESIGN: Cross-sectional, analysis of the study's baseline interviews. MAIN MEASURE: HIV sero-status, sexual practices measured with an interviewer-administered questionnaire. RESULTS: About 2% of the men were HIV positive. A logistic regression model showed HIV positivity to be associated with age (OR 1.55; 95%CI 1.22-1.95), having made a woman pregnant (OR 2.93; 95% CI 1.28-6.68), having been circumcised (OR 0.40; 95% CI 0.16-0.98), and having had sex with a man (OR 3.61; 95% CI 1.0-13.0). CONCLUSIONS: Our findings provide further evidence to suggest that circumcision is protective. There was much heterosexual risk taking among men but only pregnancy (with its association with sexual frequency) predicted HIV sero-positivity. Although relatively rare, same-sex sexual experiences were a risk factor. Male-male sexual contact is rarely assessed in HIV research in Africa and almost never addressed in general HIV prevention programming. Our findings suggest that it should be given more attention.