Migration, sexual networks, and HIV in Agbogbloshie, Ghana

Prevalence of high-risk human papillomavirus infection and cervical lesions among female migrant head porters (kayayei) in Accra, Ghana: a pilot cross-sectional study

BACKGROUND

Little attention has been given to the risk of high-risk human papillomavirus (hr-HPV) infection and cervical precancerous lesions among female migrant head porters (kayayei) in Ghana, as a vulnerable group, and to promote cervical screening in these women. This pilot study aimed to determine the prevalence of hr-HPV infection and cervical lesions among kayayei in Accra, the capital of the Greater Accra Region of Ghana and to describe our approach to triaging and treating these women.

METHODS

This descriptive cross-sectional cohort study involved the screening of 63 kayayei aged ≥ 18 years at the Tema Station and Agbogbloshie markets in March 2022 and May 2022. Concurrent hr-HPV DNA testing (with the MA-6000 platform) and visual inspection with acetic acid (VIA) was performed. We present prevalence estimates for hr-HPV DNA positivity and VIA 'positivity' as rates, together with their 95% confidence intervals (CIs). We performed univariate and multivariable nominal logistic regression to explore factors associated with hr-HPV infection.

RESULTS

Gross vulvovaginal inspection revealed vulval warts in 3 (5.0%) and vaginal warts in 2 (3.3%) women. Overall, the rate of hr-HPV positivity was 33.3% (95% CI, 21.7-46.7), whereas the VIA 'positivity' rate was 8.3% (95% CI, 2.8-18.4). In the univariate logistic regression analysis, none of the sociodemographic and clinical variables assessed, including age, number of prior pregnancies, parity, past contraceptive use, or the presence of abnormal vaginal discharge showed statistically significant association with hr-HPV positivity. After controlling for age and past contraceptive use, only having fewer than two prior pregnancies (compared to having ≥ 2) was independently associated with reduced odds of hr-HPV infection (adjusted odds ratio, 0.11; 95% CI, 0.02-0.69).

CONCLUSION

In this relatively young cohort with a high hr-HPV positivity rate of 33.3% and 8.3% of women showing cervical lesions on visual inspection, we posit that kayayei may have an increased risk of developing cervical cancer if their accessibility to cervical precancer screening services is not increased.

Prevalence of HIV in slums area: a systematic review and meta-analysis

BACKGROUND

Human Immunodeficiency Virus (HIV) remains a significant global health burden, particularly affecting vulnerable populations residing in slum areas which is characterized by overcrowding, poverty, and limited access to healthcare services, create an environment conducive to the transmission and spread of HIV. Despite the recognition of this issue, there is a lack of comprehensive understanding regarding the prevalence of HIV in slums. The aim of this study was to systematically synthesize the existing global evidence on HIV prevalence in slum populations.

METHODS

A rigorous systematic literature review was conducted by searching multiple electronic databases, including Medline via PubMed, Scopus, Embase, Web of Sciences, and Directory of Open Access Journals (DOAJ), covering the period from January 1, 1990, to March 31, 2023. The quality and risk of bias for each included study were assessed using the Newcastle-Ottawa Scale. The pooled prevalence with its corresponding 95% confidence interval (CI) was calculated using a random-effects model with the Freeman-Tukey double arcsine transformation. The degree of heterogeneity among the studies was evaluated using the I2 test. Publication bias was also assessed using Egger's test. Additionally, subgroup analysis was performed to explore potential factors contributing to the observed heterogeneity.

RESULTS

A systematic examination of the relevant literature resulted in the inclusion of a total of 22 studies for the purpose of this meta-analysis. These studies collectively assessed a sizable cohort consisting of 52,802 participants. Utilizing a random-effects model, an estimation of the overall prevalence of HIV in the slum area was determined to be 10% (95% CI: 7-13%). Further delineation through subgroup analysis based on the gender revealed a higher prevalence of HIV among women, standing at 13% (95% CI: 8-19%, 18 studies: I2 = 98%), as opposed to men, where the prevalence was found to be 8% (95% CI: 6-12%, 16 studies: I2 = 95%). A geographical breakdown of the included studies revealed that Africa exhibited the highest prevalence, with a figure of 11% (95% CI: 9-13%, 18 studies: I2 = 98%). Subsequently, studies conducted in the American continent reported a prevalence of 9% (95% CI: 7-11%, 2 studies: I2 = 57%). The Asian continent, on the other hand, displayed the lowest prevalence of 1% (95% CI: 0-3%, 2 studies: I2 = 94%). Notably, studies employing rapid tests indicated a prevalence of 13% (95% CI: 9-17%, 6 studies: I2 = 94%), while those relying on self-reported data reported a lower prevalence of 8% (95% CI: 5-11%, 6 studies: I2 = 99%). Moreover, studies utilizing ELISA reported a prevalence of 9% (95% CI: 6-12%, 10 studies: I2 = 96%). Finally, it was determined that studies conducted in upper-middle-income countries reported a higher prevalence of 20% (95% CI: 16-24%, 5 studies: I2 = 45%), whereas studies conducted in lower- and middle-income countries reported a prevalence of 8% (95% CI: 6-10%, 12 studies: I2 = 98%).

CONCLUSION

The current study elucidates the troublingly high prevalence of HIV infection within slums area. Also, this finding underscores the urgent necessity for targeted and tailored interventions specifically aimed at curtailing the spread of HIV within slums. Policymakers must take cognizance of these results and devote their efforts towards the implementation of effective strategies to mitigate gender disparities, address poverty alleviation, and empower the inhabitants of these marginalized areas.

Novel Location-Based Survey Using Cognitive Interviews to Assess Geographic Networks and Hotspots of Sex and Drug Use: Implementation and Validation Study

BACKGROUND

The Ending the HIV Epidemic initiative in the United States relies on HIV hotspots to identify where to geographically target new resources, expertise, and technology. However, interventions targeted at places with high HIV transmission and infection risk, not just places with high HIV incidence, may be more effective at reducing HIV incidence and achieving health equity.

OBJECTIVE

We described the implementation and validation of a web-based activity space survey on HIV risk behaviors. The survey was intended to collect geographic information that will be used to map risk behavior hotspots as well as the geography of sexual networks in Los Angeles County.

METHODS

The survey design team developed a series of geospatial questions that follow a 3-level structure that becomes more geographically precise as participants move through the levels. The survey was validated through 9 cognitive interviews and iteratively updated based on participant feedback until the saturation of topics and technical issues was reached.

RESULTS

In total, 4 themes were identified through the cognitive interviews: functionality of geospatial questions, representation and accessibility, privacy, and length and understanding of the survey. The ease of use for the geospatial questions was critical as many participants were not familiar with mapping software. The inclusion of well-known places, landmarks, and road networks was critical for ease of use. The addition of a Google Maps interface, which was familiar to many participants, aided in collecting accurate and precise location information. The geospatial questions increased the length of the survey and warranted the inclusion of features to simplify it and speed it up. Using nicknames to refer to previously entered geographic locations limited the number of geospatial questions that appeared in the survey and reduced the time taken to complete it. The long-standing relationship between participants and the research team improved comfort to disclose sensitive geographic information related to drug use and sex. Participants in the cognitive interviews highlighted how trust and inclusive and validating language in the survey alleviated concerns related to privacy and representation.

CONCLUSIONS

This study provides promising results regarding the feasibility of using a web-based mapping survey to collect sensitive location information relevant to ending the HIV epidemic. Data collection at several geographic levels will allow for insights into spatial recall of behaviors as well as future sensitivity analysis of the spatial scale of hotspots and network characteristics. This design also promotes the privacy and comfort of participants who provide location information for sensitive topics. Key considerations for implementing this type of survey include trust from participants, community partners, or research teams to overcome concerns related to privacy and comfort. The implementation of similar surveys should consider local characteristics and knowledge when crafting the geospatial components.

Mobility and HIV care engagement: a research agenda

INTRODUCTION

Mobility is common and an essential livelihood strategy in sub-Saharan Africa (SSA). Mobile people suffer worse outcomes at every stage of the HIV care cascade compared to non-mobile populations. Definitions of mobility vary widely, and research on the role of temporary mobility (as opposed to permanent migration) in HIV treatment outcomes is often lacking. In this article, we review the current landscape of mobility and HIV care research to identify what is already known, gaps in the literature, and recommendations for future research.

DISCUSSION

Mobility in SSA is closely linked to income generation, though caregiving, climate change and violence also contribute to the need to move. Mobility is likely to increase in the coming decades, both due to permanent migration and increased temporary mobility, which is likely much more common. We outline three central questions regarding mobility and HIV treatment outcomes in SSA. First, it is unclear what aspects of mobility matter most for HIV care outcomes and if high-risk mobility can be identified or predicted, which is necessary to facilitate targeted interventions for mobile populations. Second, it is unclear what groups are most vulnerable to mobility-associated treatment interruption and other adverse outcomes. And third, it is unclear what interventions can improve HIV treatment outcomes for mobile populations.

CONCLUSIONS

Mobility is essential for people living with HIV in SSA. HIV treatment programmes and broader health systems must understand and adapt to human mobility, both to promote the rights and welfare of mobile people and to end the HIV pandemic.

Molecular Epidemiology of HIV-1 in Ghana: Subtype Distribution, Drug Resistance and Coreceptor Usage

The greatest HIV-1 genetic diversity is found in West/Central Africa due to the pandemic’s origins in this region, but this diversity remains understudied. We characterized HIV-1 subtype diversity (from both sub-genomic and full-genome viral sequences), drug resistance and coreceptor usage in 103 predominantly (90%) antiretroviral-naive individuals living with HIV-1 in Ghana. Full-genome HIV-1 subtyping confirmed the circulating recombinant form CRF02_AG as the dominant (53.9%) subtype in the region, with the complex recombinant 06_cpx (4%) present as well. Unique recombinants, most of which were mosaics containing CRF02_AG and/or 06_cpx, made up 37% of sequences, while “pure” subtypes were rare (<6%). Pretreatment resistance to at least one drug class was observed in 17% of the cohort, with NNRTI resistance being the most common (12%) and INSTI resistance being relatively rare (2%). CXCR4-using HIV-1 sequences were identified in 23% of participants. Overall, our findings advance our understanding of HIV-1 molecular epidemiology in Ghana. Extensive HIV-1 genetic diversity in the region appears to be fueling the ongoing creation of novel recombinants, the majority CRF02_AG-containing, in the region. The relatively high prevalence of pretreatment NNRTI resistance but low prevalence of INSTI resistance supports the use of INSTI-based first-line regimens in Ghana.

E-waste it wisely: lessons from Africa

E-waste is the world’s fastest growing and most valuable domestic waste stream. The increasing production of e-waste is driving elevated levels of export from developed to developing countries. Although countries worldwide are actively recognising the issues around e-waste and introducing policies, legislation or regulations governing e-waste, a large fraction of e-waste, goes undocumented at its end-of-life. Much of the global e-waste is accumulating in open dumpsites in several African countries. Using available data, we calculate the total e-waste in Africa (locally produced plus imported e-waste) for 2019 to be between 5.8 and 3.4 metric tonnes (Mt). This is believed to be an underestimate, large data gaps exist, hindering more precise estimates. The data is further complicated by, sometimes intentional, differences in labelling and reporting between formal and intermittent informal importers. Based on the available data, the main African recipients of e-waste are Nigeria, Ghana, and Tanzania, with Kenya, Senegal and Egypt featuring as countries of concern. The lack of proper waste management in the recipient developing countries, leads to environmental contamination and human exposure. A coordinated, regional and global, approach is needed in tackling e-waste. Regulatory frameworks, together with monitoring and compliance mechanisms need to be developed, financed, and enforced.

Is It the Timing? Short-Term Mobility and Coital Frequency in Agbogbloshie, Ghana

Short-term mobility is often associated with increased sexual risk behavior. Mobile individuals often have higher rates of sexual risk behavior compared to non-mobile individuals, but the reasons why are not clear. Using monthly retrospective panel data from 202 men and 282 women in Agbogbloshie, Ghana, we tested whether short-term mobility was associated with changes in coital frequency, and whether the association was due to the act of travel in the given month (e.g., enabling higher risk behavior), the reason for travel, or an individual's travel propensity at other times in the year. Overnight travel specifically to visit family or friends, or for education, health, or other reasons, was associated with increased coital frequency for men. However, men with higher travel propensities had lower overall coital frequency and the act of traveling enabled more sex only for the most frequent male travelers. Men who seldom traveled had much higher coital frequency, but the act of traveling was not associated with additional sex acts. For women, travel for education, health, or other reasons increased coital frequency. Occasional female travelers had slightly more sex acts compared to non-mobile women, and the act of traveling for these women was associated with slight increases in coital frequency, supporting the enabling hypothesis. Highly mobile women had fewer sex acts per month on average. Our findings suggest that mobility characteristics measured on a broad temporal scale, as well as the reason for mobility, are important to understand the relationship between short-term mobility and sexual behavior.

Effects of residential mobility and migration on standards of living in Dar es Salaam, Tanzania: A life-course approach

Rural-to-urban migration and intra-urban residential mobility often lead to improved living conditions. However, it is not clear if this is true for all, especially in cities in developing countries, where inequalities persist and upward mobility remains elusive for marginalized populations. We investigate the effects of intra-urban residential mobility and rural-to-urban migration on standards of living in Dar es Salaam, Tanzania. We examine the entire residential history of individuals and assess temporal changes in living conditions in their respective housing careers. We use four different aspects of housing as indicators of living conditions from a survey conducted by the World Bank Group that captured the residential history of 2,397 individuals in Dar es Salaam from a spatially representative sample of households. We find that improvements in housing conditions are uneven, a considerable proportion of individuals remained perpetually deprived of adequate housing despite migrating from rural areas to Dar es Salaam and changing multiple homes within the city during their tenure. Our findings indicate that housing disparities persist over time for many. Socioeconomic groups such as migrants tend to experience significant improvements after moving to the city but show limited upward mobility afterwards, an aspect that is rarely addressed in policy discourse on equitable access to adequate housing.

A method for statistical analysis of repeated residential movements to link human mobility and HIV acquisition

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.

Coital Frequency and Male Concurrent Partnerships During Pregnancy and Postpartum in Agbogbloshie, Ghana

During pregnancy and postpartum, women in high HIV prevalence regions continue to be at high risk for acquiring HIV, due to both behavioral and biological mechanisms, despite declines in coital frequency as a pregnancy advances. We estimated differences in rates of partnership concurrency for men with and without pregnant or postpartum sexual partners. We used monthly retrospective panel data from Ghana from three perspectives: couple-level data, female reports of pregnancy and male partner concurrency, and male reports of concurrent partnerships and female partner pregnancy. Coital frequency increased during the first trimester and then declined with advancing pregnancy. However, in all three analyses, there was no compelling evidence that men with pregnant or postpartum partners had additional concurrent partnerships. Our findings suggest that even though women's sexual activity likely declines during pregnancy and postpartum, they may not be at increased risk of HIV/STI due to their partners seeking additional partnerships.

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

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.

Revisiting the Housing-Health Relationship for HIV-Positive Persons: Qualitative Evidence From the Lower Manya Krobo District, Ghana

The relationship between housing and HIV infection is complex. On one hand, poor housing arrangements may affect the health of persons living with HIV/AIDS (PLWHAs). On the other hand, PLWHAs may be more likely to live in substandard homes because of their health. We used qualitative in-depth individual interviews of 38 PLWHAs attending voluntary counseling services at two government hospitals in the Lower Manya Krobo District (LMKD) in the Eastern region of Ghana to examine their housing and health outcomes. Results show that the majority of PLWHAs lived in homes that lacked basic amenities, were overcrowded, had structural deficiencies, and were noisy and dirty. They suffered from poor housing conditions mainly because of their HIV serostatus, as this affected their ability to finance adequate homes, while HIV-related stigmatization led to eviction from either family homes or rented facilities.

Geographic mobility and potential bridging for sexually transmitted infections in Agbogbloshie, Ghana

Short-term mobility can significantly influence the spread of infectious disease. In order for mobile individuals to geographically spread sexually transmitted infections (STIs), individuals must engage in sexual acts with different partners in two places within a short time. In this study, we considered the potential of mobile individuals as bridge populations - individuals who link otherwise disconnected sexual networks and contributed to ongoing STI transmission. Using monthly retrospective panel data, we examined associations between short-term mobility and sexual partner concurrency in Agbogbloshie, Ghana. We also examined bridging by the location of sex acts and the location of sexual partners in concurrent triads, and whether mobile individuals from our sample were more likely to be members of geographic bridging triads. Although reported rates of sexual partnership concurrency were much higher for men compared to women, mobility was only associated with increased concurrency for women. Additionally, this association held for middle-distance mobility and short-duration trips for women. Taking into account the location of sex acts and the location of sexual partners, about 22% of men (21.7% and 22.4% for mobile and non-mobile men, respectively) and only 3% of women (1.4% and 3.3% for mobile and non-mobile women, respectively) were potential bridges for STIs over the last year. Our results highlight the gendered nature of mobility and sexual risk behavior, reflecting the normative social context that encourages women to conceal certain types of sexual behavior.

Space-time migration patterns and risk of HIV acquisition in rural South Africa

Objective:

To quantify the space-time dimensions of human mobility in relationship to the risk of HIV acquisition.

Methods:

We used data from the population cohort located in a high HIV prevalence, rural population in KwaZulu-Natal, South Africa (2000–2014). We geolocated 8006 migration events (representing 1 028 782 km traveled) for 17 743 individuals (≥15 years of age) who were HIV negative at baseline and followed up these individuals for HIV acquisition (70 395 person-years). Based on the complete geolocated residential history of every individual in this cohort, we constructed two detailed time-varying migration indices. We then used interval-censored Cox proportional hazards models to quantify the relationship between the migration indices and the risk of HIV acquisition.

Results:

In total, 17.4% of participants migrated at least once outside the rural study community during the period of observation (median migration distance = 107.1 km, interquartile range 18.9–387.5). The two migration indices were highly predictive of hazard of HIV acquisition (P < 0.01) in both men and women. Holding other factors equal, the risk of acquiring HIV infection increased by 50% for migration distances of 40 km (men) and 109 km (women). HIV acquisition risk also increased by 50% when participants spent 44% (men) and 90% (women) of their respective time outside the rural study community.

Conclusion:

This in-depth analysis of a population cohort in a rural sub-Saharan African population has revealed a clear nonlinear relationship between distance migrated and HIV acquisition. Our findings show that even relatively short-distance migration events confer substantial additional risk of acquisition.

Effectiveness of combination packages for HIV-1 prevention in sub-Saharan Africa depends on partnership network structure: a mathematical modelling study

OBJECTIVES

Combination packages for HIV prevention can leverage the effectiveness of biomedical and behavioural elements to lower disease incidence with realistic targets for individual and population risk reduction. We investigated how sexual network structures can maximise the effectiveness of a package targeting sexually active adults in sub-Saharan Africa (SSA) with intervention components for medical male circumcision (MMC) and sexual partnership concurrency (having >1 ongoing partner).

METHODS

Network-based mathematical models of HIV type 1 (HIV-1) transmission dynamics among heterosexual couples were used to explore how changes to MMC alone and in combination with changes to concurrency impacted endemic HIV-1 prevalence and incidence. Starting from a base model parameterised from empirical data from West Africa, we simulated the prevalence of circumcision from 10% to 90% and concurrency was modelled at four discrete levels corresponding to values observed across SSA.

RESULTS

MMC and concurrency could contribute to the empirical variation in HIV-1 disease prevalence across SSA. Small reductions in concurrency resulted in large declines in HIV-1 prevalence. Scaling up circumcision in low-concurrency settings yields a greater relative benefit, but the absolute number of infections averted depends on both the circumcision coverage and baseline incidence. Epidemic extinction with this package will require substantial scale-up of MMC in low-concurrency settings.

CONCLUSIONS

Dynamic sexual network structure should be considered in the design and targeting of MMC within combination HIV-1 prevention packages. Realistic levels of coverage for these packages within southern Africa could lead to a reduction of incidence to the low levels observed in western Africa, and possibly, epidemic extinction.

Access to health in city slum dwellers: The case of Sodom and Gomorrah in Accra, Ghana

Background

Rapid rural-urban migration of people to cities is a reality around the globe that has increased city slum dwellers. Sodom and Gomorrah is a city slum located in the heart of Accra, Ghana. Like other slums, it lacks basic amenities necessary for dwellers’ quality of life. This study describes residents’ access to health and factors associated with the use of healthcare facilities.

Methods

Questionnaires were administered in systematically selected shacks across the entire slum. Data on demographic characteristics, existent health facilities and number of users, health-insured residents and knowledge of common diseases were collected.

Results

Majority of the residents were from the northern parts of Ghana, relative to the south and a few of them come from other parts of West Africa. Seventy-one percent of residents had never visited a health facility in the last 5 years. When necessary, they access health care from drug stores (61.1%) or hospitals (33.1%). Residents’ age, educational status, income, health knowledge and membership of National Health Insurance Scheme were significantly (p < 0.05) associated with the use of healthcare facilities. Younger residents and those without National Health Insurance Scheme membership, formal education, no knowledge of common illnesses and regular income were significantly less likely to use a healthcare facility. For most residents, neither distance (73.2%) nor transportation to health facilities was a problem (74.1%).

Conclusion

Conditions of profound environmental hazards, overcrowding, poor-quality housing and lack of health care in Sodom and Gomorrah pose grave threats to the health of the inhabitants. Multisectoral interventions and resource mobilisation championed by the Ministry of Local Government and Rural Development are needed to alter the trend.

Minimal coital dilution in Accra, Ghana

BACKGROUND

Coital dilution, the reduction in the coital frequency per partner when an additional ongoing partner is added, may reduce the transmission potential of partnership concurrency for HIV and other sexually transmitted infections. Empirical estimates of dilution, especially dilution of sexual acts unprotected by condoms, are needed to inform prevention research.

METHODS

Sexually active adults in Accra, Ghana were recruited in a multistage household probability sample. Degree (number of ongoing partners), total acts, and unprotected acts were measured retrospectively for each month in the past year through an event history calendar. Random-effects negative binomial models estimated the association between degree and coital frequency.

RESULTS

Compared with person-months with a single partner (monogamy), 2.06 times as many total acts and 1.94 times as many unprotected acts occurred in months with 2 partners. In months with 3 partners, 2.90 times as many total acts and 2.39 times as many unprotected acts occurred compared with monogamous months. Total acts but not unprotected acts also declined with partnership duration.

CONCLUSIONS

No dilution was observed for total acts with up to 3 concurrent partners, but a small amount of dilution was observed for unprotected acts for months with multiple concurrencies. This suggests moderate selective condom use in months with multiple concurrencies. The implications of the observed dilution for future HIV transmission must be investigated with mathematical models.