Commercial sex and the spread of HIV in four cities in sub-Saharan Africa

Self-reported and pill count measures of adherence to oral HIV PrEP among female sex workers living in South-Western Uganda

Background

Female sex workers (FSWs) in Uganda are at high risk of HIV infection. Scaling up oral pre-exposure prophylaxis (PrEP) will reduce HIV incidence if high levels of adherence are maintained. This study evaluates PrEP adherence using clinic-based pill counts and self-reported measures, and factors associated with protective levels of adherence.

Methods

Participants were sex workers who had been taking PrEP for at least 5 months and were attending routine follow-up visits for PrEP care in fishing communities and along the Trans-African Highway. Participants who had a pill count showing at least 85% use since their last clinic visit and those who reported taking their PrEP every day in the last 5 months were categorised as having ‘protective adherence’. Spearman’s correlation and weighted kappa assessed the relationship between pill count and self-reported measures. Bivariate and multivariate logistic regression was used to determine factors associated with protective adherence as measured by pill count.

Results

We recruited 524 FSWs, with a median age of 29 years (IQR 23–35). Participants were recruited from fishing communities and Trans-African Highway towns (n = 297, 56.7%, and n = 227, 43.0%). Nearly three quarters (n = 372, 71.0%) of women were estimated to have protective adherence based on pill count (i.e., a pill count of >85%) and 50.4% by self-report in last 3 months. There was a strong positive association between self-reported measures and pill count measures (rest = 0.6453, 95% CI = 0.5924–0.6927) and a moderate agreement between self-reported measures and pill count measures, κ = 0.544 (95%CI = 0.4869–0.6011, p < 0.001).

Factors associated with protective adherence included being aged 35 years or older (aOR = 2.40, 95% CI = 1.17–4.86), living in a fishing community (aOR = 1.45, 95% CI = 0.62–3.38), and having an STI in last 3 months (aOR = 1.64, 95% CI = 1.07–2.49).

Conclusion

Our findings indicate that PrEP-experienced FSWs attending clinical follow-up visits reported high protective levels of oral pre-exposure prophylaxis, as measured by both pill count and self-reported measures, and a moderate agreement between pill count and self-reported measures.

HIV prevalence and associated factors among female sex workers in Ethiopia, east Africa: A cross-sectional study using a respondent-driven sampling technique

BACKGROUND

HIV acquisition among Female Sex Workers (FSWs) is 30 times higher than the acquisition rate among females in the respective general population. A higher HIV burden in FSWs challenges the prevention and control of the virus in other population groups. However, there is inadequate evidence on the burden of HIV among FSWs in Ethiopia. This study was conducted to assess the extent of HIV and associated factors among FSWs in the country.

METHODS

This was a cross-sectional study that involved a total of 6,085 FSWs. The participants were selected using a respondent-driven sampling technique (RDS). FSWs who lived at the study sites for at least a month before the study time were considered eligible for recruitment. The study was conducted from January 01 to June 30, 2020 in 16 cities across Ethiopia. A mixed-effect logistic regression model was applied to determine factors associated with HIV positivity.

FINDINGS

The pooled HIV prevalence among FSWs in this study was 18·7% (95% CI: 17·8, 19·7) with considerable variation across cities. The highest HIV prevalence was observed in Bahir Dar city, 28·2% (95% CI: 23·9, 33.0) and the lowest was seen in Shashemene city, 14.0% (95% CI: 10·2, 18·9). The odds of HIV positivity in FSWs was associated with being older than 35 years of age (AOR = 8·1; 95% CI: 6·1, 10·3), reactive for Treponema Pallidum (AOR = 2·6; 95% CI: 1·0, 3·4), being widowed (OR = 2·2; 95% CI: 1·6, 2·9), not able to read and write (OR = 2·0; 95% CI: 1·5, 2·4), incidence of condom breakage (OR = 1·5; 95% CI: 1·2, 1·7) and having a history of STIs (OR = 1·3; 95% CI: 1·1, 1·6).

INTERPRETATION

One in five FSWs was HIV positive. HIV prevalence was higher in the older age groups and in those who were positive for Treponema Pallidum (Syphilis). The findings indicated the importance of strengthening HIV prevention and control in FSWs to achieve the national goal to eliminate HIV by 2030.

FUNDING

The study was supported by The Ethiopian Ministry of Health through the Federal HIV/AIDS Prevention and Control Office.

Status of the HIV epidemic in key populations in the Middle East and north Africa: knowns and unknowns

The Middle East and north Africa is one of only two world regions where HIV incidence is on the rise, with most infections occurring among key populations: people who inject drugs, men who have sex with men, and female sex workers. In this Review, we show a trend of increasing HIV prevalence among the three key populations in the Middle East and north Africa. Although the epidemic continues at a low level in some countries or localities within a country, there is evidence for concentrated epidemics, with sustained transmission at considerable HIV prevalence among people who inject drugs and men who have sex with men in over half of countries in the region with data, and among female sex workers in several countries. Most epidemics emerged around 2003 or thereafter. The status of the epidemic among key populations remains unknown in several countries due to persistent data gaps. The HIV response in Middle East and north Africa remains far below global targets for prevention, testing, and treatment. It is hindered by underfunding, poor surveillance, and stigma, all of which are compounded by widespread conflict and humanitarian crises, and most recently, the advent of COVID-19. Investment is needed to put the region on track towards the target of eliminating HIV/AIDS as a global health threat by 2030. Reaching this target will not be possible without tailoring the response to the needs of key populations, while addressing, to the extent possible, the complex structural and operational barriers to success.

The Risk of HIV/STDs Infection and Transmission Among Never-Married Male Migrants in China: Is Risk Attributable to Bachelorhood or Migration?

In the context of sex-ratio imbalance and rural-to-urban migration in China, never-married male migrants may become a vulnerable group as well as a bridge population that facilitates HIV/STDs transmission. It is still not clear, however, whether increased HIV/STDs transmission risk can be attributed to bachelorhood, migration, or both. This study identified the contributions of bachelorhood and migration to an increased risk of HIV/STDs infection, as well as the risk of HIV/STDs transmission across populations and regions. Data were from a cross-sectional questionnaire survey, in which 180 never-married non-migrant males in rural areas, 558 never-married male migrants, and 302 married male migrants in urban areas of China were interviewed in 2017. Results showed that never-married male migrants are more likely to engage in commercial sex and unsafe sex than never-married non-migrant males, and their likelihood of engaging in unsafe sex was also higher than married male migrants. Although never-married male migrants were less likely to have multiple sex partners than married male migrants, they were more likely to have multiple sex partners and sex partners from different regions than never-married non-migrant males. These findings indicate that both migration and bachelorhood increase the risk of HIV/STDs infection for never-married male migrants, and migration also increases the risk of HIV/STDs transmission across populations and regions.

Comparison of two simulators for individual based models in HIV epidemiology in a population with HSV 2 in Yaoundé (Cameroon)

Model comparisons have been widely used to guide intervention strategies to control infectious diseases. Agreement between different models is crucial for providing robust evidence for policy-makers because differences in model properties can influence their predictions. In this study, we compared models implemented by two individual-based model simulators for HIV epidemiology in a heterosexual population with Herpes simplex virus type-2 (HSV-2). For each model simulator, we constructed four models, starting from a simplified basic model and stepwise including more model complexity. For the resulting eight models, the predictions of the impact of behavioural interventions on the HIV epidemic in Yaoundé-Cameroon were compared. The results show that differences in model assumptions and model complexity can influence the size of the predicted impact of the intervention, as well as the predicted qualitative behaviour of the HIV epidemic after the intervention. These differences in predictions of an intervention were also observed for two models that agreed in their predictions of the HIV epidemic in the absence of that intervention. Without additional data, it is impossible to determine which of these two models is the most reliable. These findings highlight the importance of making more data available for the calibration and validation of epidemiological models.

Assessing the Potential Impact of Disruptions Due to COVID-19 on HIV Among Key and Lower-Risk Populations in the Largest Cities of Cameroon and Benin

BACKGROUND

The COVID-19 pandemic indirectly impacts HIV epidemiology in Central/West Africa. We estimated the potential impact of COVID-19-related disruptions to HIV prevention/treatment services and sexual partnerships on HIV incidence and HIV-related deaths among key populations including female sex workers (FSW), their clients, men who have sex with men, and overall.

SETTING

Yaoundé (Cameroon) and Cotonou (Benin).

METHODS

We used mathematical models of HIV calibrated to city population-specific and risk population-specific demographic/behavioral/epidemic data. We estimated the relative change in 1-year HIV incidence and HIV-related deaths for various disruption scenarios of HIV prevention/treatment services and decreased casual/commercial partnerships, compared with a scenario without COVID-19.

RESULTS

A 50% reduction in condom use in all partnerships over 6 months would increase 1-year HIV incidence by 39%, 42%, 31%, and 23% among men who have sex with men, FSW, clients, and overall in Yaoundé, respectively, and 69%, 49%, and 23% among FSW, clients, and overall, respectively, in Cotonou. Combining a 6-month interruption of ART initiation and 50% reduction in HIV prevention/treatment use would increase HIV incidence by 50% and HIV-related deaths by 20%. This increase in HIV infections would be halved by a simultaneous 50% reduction in casual and commercial partnerships.

CONCLUSIONS

Reductions in condom use after COVID-19 would increase infections among key populations disproportionately, particularly FSW in Cotonou, who need uninterrupted condom provision. Disruptions in HIV prevention/treatment services have the biggest impacts on HIV infections and deaths overall, only partially mitigated by equal reductions in casual/commercial sexual partnerships. Maintaining ART provision must be prioritized to minimize short-term excess HIV-related deaths.

Quantifying the Evolving Contribution of HIV Interventions and Key Populations to the HIV Epidemic in Yaoundé, Cameroon

BACKGROUND

Key populations (KP) including men who have sex with men (MSM), female sex workers (FSW), and their clients are disproportionately affected by HIV in Sub-Saharan Africa. We estimated the evolving impact of past interventions and contribution of unmet HIV prevention/treatment needs of key populations and lower-risk groups to HIV transmission.

SETTING

Yaoundé, Cameroon.

METHODS

We parametrized and fitted a deterministic HIV transmission model to Yaoundé-specific demographic, behavioral, HIV, and intervention coverage data in a Bayesian framework. We estimated the fraction of incident HIV infections averted by condoms and antiretroviral therapy (ART) and the fraction of all infections over 10-year periods directly and indirectly attributable to sex within and between each risk group.

RESULTS

Condom use and ART together may have averted 43% (95% uncertainty interval: 31-54) of incident infections over 1980-2018 and 72% (66-79) over 2009-2018. Most onward transmissions over 2009-2018 stemmed from sex between lower-risk individuals [47% (32-61)], clients [37% (23-51)], and MSM [35% (20-54)] with all their partners. The contribution of commercial sex decreased from 25% (8-49) over 1989-1998 to 8% (3-22) over 2009-2018, due to higher intervention coverage among FSW.

CONCLUSION

Condom use and recent ART scale-up mitigated the HIV epidemic in Yaoundé and changed the contribution of different partnerships to onward transmission over time. Findings highlight the importance of prioritizing HIV prevention and treatment for MSM and clients of FSW whose unmet needs now contribute most to onward transmission, while maintaining services that successfully reduced transmissions in the context of commercial sex.

Mathematical Model Impact Analysis of a Real-Life Pre-exposure Prophylaxis and Treatment-As-Prevention Study Among Female Sex Workers in Cotonou, Benin

BACKGROUND

Daily pre-exposure prophylaxis (PrEP) and treatment-as-prevention (TasP) reduce HIV acquisition and transmission risk, respectively. A demonstration study (2015-2017) assessed TasP and PrEP feasibility among female sex workers (FSW) in Cotonou, Benin.

SETTING

Cotonou, Benin.

METHODS

We developed a compartmental HIV transmission model featuring PrEP and antiretroviral therapy (ART) among the high-risk (FSW and clients) and low-risk populations, calibrated to historical epidemiological and demonstration study data, reflecting observed lower PrEP uptake, adherence and retention compared with TasP. We estimated the population-level impact of the 2-year study and several 20-year intervention scenarios, varying coverage and adherence independently and together. We report the percentage [median, 2.5th-97.5th percentile uncertainty interval (95% UI)] of HIV infections prevented comparing the intervention and counterfactual (2017 coverages: 0% PrEP and 49% ART) scenarios.

RESULTS

The 2-year study (2017 coverages: 9% PrEP and 83% ART) prevented an estimated 8% (95% UI 6-12) and 6% (3-10) infections among FSW over 2 and 20 years, respectively, compared with 7% (3-11) and 5% (2-9) overall. The PrEP and TasP arms prevented 0.4% (0.2-0.8) and 4.6% (2.2-8.7) infections overall over 20 years, respectively. Twenty-year PrEP and TasP scale-ups (2035 coverages: 47% PrEP and 88% ART) prevented 21% (17-26) and 17% (10-27) infections among FSW, respectively, and 5% (3-10) and 17% (10-27) overall. Compared with TasP scale-up alone, PrEP and TasP combined scale-up prevented 1.9× and 1.2× more infections among FSW and overall, respectively.

CONCLUSIONS

The demonstration study impact was modest, and mostly from TasP. Increasing PrEP adherence and coverage improves impact substantially among FSW, but little overall. We recommend TasP in prevention packages.

HIV infections among female sex workers in Mombasa, Kenya: current prevalence and trends over 25 years

Over 20 years, interventions have targeted HIV among female sex workers (FSWs) in Kenya given their central role in new infections. To determine the effects of these interventions, we assessed the prevalence and correlates of HIV among a random sample of FSWs and modelled prevalence estimates from studies since 1993. FSWs aged 16-34 years were enrolled through multi-stage sampling. Regression models identified correlates of HIV infection. Generalised linear mixed modelling estimated temporal changes in prevalence between 1993 and 2016. 882 FSWs were enrolled. Prevalence rose from 3.6% among 16-20-year-olds to 31.6% among 31-34-year-old FSWs. Those aged 31 to 34 years had greater odds of HIV compared to those 16 to 20 years (AOR 14.2, 95% CI, 5.5-36.8). Infection was less prevalent among FSWs with tertiary education compared to those with primary or no education (AOR 0.23, 95% CI, 0.07-0.78). There was an overall 30% reduction in prevalence from 1993 to 2016 with an average annual decline of 3%. About one in ten FSWs in Mombasa are currently infected with HIV. Considering FSWs' central role in sustaining population-level infections, these initiatives require continued support, focusing on reducing transmission from older FSWs and those with less education.

Changing Trends of HIV, Syphilis, and Hepatitis C among Male Migrant Workers in Chongqing, China: Nine Consecutive Cross-Sectional Surveys, 2010-2018

Background: Male migrant workers (MMWs) have been reported to be vulnerable to human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Chongqing, China is one of the major migration destinations and hotspots of HIV. This study aims to explore the prevalence of HIV, syphilis, and hepatitis C virus (HCV), as well as HIV-related knowledge and behaviors, among MMWs in Chongqing. Methods: Questionnaire surveys were conducted, and blood samples were collected and examined among MMWs selected by two-stage stratified sampling in Chongqing from 2010 to 2018. The Cochran–Armitage trend test was conducted to observe the trends in the prevalence of HIV, syphilis, and HCV, as well as HIV-related knowledge and behaviors. The Chi-square test and Binary Logistic Regression were conducted to observe the distinctions between different groups. Results: The overall HIV prevalence was 0.6% with an increasing trend (0.2% to 0.9%, p < 0.001), whereas the overall HCV prevalence was 0.5% with a decreasing trend (0.5% to 0.4%, p < 0.001). The overall syphilis prevalence was 1.3% in the ≥50 age group, 1.0% in the 30–49 age group, and higher than 0.3% in the 16–29 group (X² = 19.527, p < 0.001). An uptrend (80.2%–80.6%, p < 0.001) was observed in correct HIV-related knowledge. The 16–29 ((Odds Ratio) OR: 1.575; 95%CI (Confidence Interval): 1.380–1.798; p < 0.001) and 30–49 (OR: 1.697; 95%CI: 1.495–1.926; p < 0.001) age groups had 1.575 and 1.697 times correct HIV-related knowledge more than the ≥50 age group. The proportion of subjects engaged in commercial sex in the past year (7.7%–13.3%, p < 0.001), consistent condom use during this activity (20.5%–54.0%, p < 0.001), and condom use in the last commercial sex (48.6%–72.1%, p = 0.020) were increasing. The risk of engaging in commercial sex in the past year in the 16–29 age group was 0.768 times (OR: 0.768; 95%CI: 0.643–0.917; p = 0.003) less than that in the ≥50 age group. The risk of engaging in non-regular sex in the past year in the 16–29 (OR: 2.819; 95%CI: 2.317–3.431; p < 0.001) and 30–49 (OR: 1.432; 95%CI: 1.184–1.733; p < 0.001) age groups were 2.819 and 1.432 times more than that in the ≥50 age group. The risk of engaging in anal sex in the past year in the 16–29 age group was 6.333 times (OR: 6.333; 95%CI: 1.468–27.327; p < 0.013) more than that in the ≥50 age group. The proportion of consistent condom use during non-regular sex in the past year (10.9%–47.3%, p < 0.001) and condom use in the last non-regular sex (40.8%–71.1%, p < 0.001) increased remarkably. The possibilities of consistent condom use during commercial sex in the past year in the 16–29 (OR: 2.606; 95%CI: 1.847–3.677; p < 0.001) and 30–49 (OR: 1.632; 95%CI: 1.214–2.195; p = 0.001) age groups were 2.606 and 1.632 times more than that in the ≥50 age group. The possibilities of condom use in the last commercial sex in the 16–29 (OR: 1.805; 95%CI: 1.258–2.589; p = 0.001) and 30–49 (OR: 1.360; 95%CI: 1.016–1.821; p = 0.039) age groups were 1.805 and 1.360 times more than that in the ≥50 age group. The possibilities of consistent condom use during non-regular sex in the past year (OR: 1.628; 95%CI: 1.066–2.484; p = 0.024) and condom use in the last non-regular sex (OR: 1.671; 95%CI: 1.148–2.433; p = 0.007) in the 16–29 age group were 1.628 and 1.671 times more than those in the ≥50 age group, respectively. Conclusion: An upward trend of HIV and a downward trend of HCV were observed among MMWs in Chongqing from 2010 to 2018. We also found an increase in commercial sex and inadequate condom use during high-risk behaviors among this population. The overall syphilis prevalence in the middle-aged and elderly groups was higher than in the young group, and elderly MMWs were more likely to engage in unprotected high-risk behaviors. Thus, targeted STI prevention for MMWs in Chongqing, especially those aged 50 years and above, is urgently needed.

Lipid-drug conjugates and associated carrier strategies for enhanced antiretroviral drug delivery

Mortality rate of patients infected with HIV-1 has been significantly reduced by using HAART. However, the virus to date has not been eradicated. Transmission of HIV-1 infection through sexual intercourse remains an ongoing challenge, with increased risk of infection occurring in women. Interestingly, ARV drugs can be chemically linked with lipids to produce lipid-drug conjugates (LDCs). This alters pharmacokinetic properties of ARV drugs and thereby resulting in improved effectiveness. Although LDCs can be administered without a delivery carrier, they are usually incorporated into suitable delivery systems such as lipid nanoparticles, polymeric nanoparticles, micelles, liposomes, emulsions, and carbon nanotubes. Given that LDCs have the potential to improve oral bioavailability, lipophilicity, toxicity, and drug targeting, it is of our great interest to review strategies of lipid-drug conjugation together with their delivery systems for enhanced antiretroviral efficacy.

Single Mothers and Female Sex Workers in Zambia Have Similar Risk Profiles

The aim of the study was to compare reproductive health and high-risk behaviors in female sex workers (FSWs) and single mothers (SMs) in Zambia's two largest cities, Lusaka and Ndola. FSWs were invited from known community hot spots, and sexually active HIV- SMs were referred from infant vaccination services for free and anonymous screening and treatment for HIV and other sexually transmitted infections (STIs) and long acting reversible contraception. A subset completed an interviewer-administered survey. From 2012 to 2016, 1,893 women (1,377 FSWs and 516 HIV- SMs) responded to referrals. HIV prevalence was 50% in Lusaka and 33% in Ndola FSWs. Positive syphilis serology (rapid plasmin reagin) was found in 29%-31% of HIV+ FSWs and 9%-12% of HIV- FSWs and SMs. Trichomonas was more common in Ndola (11%-12%), compared with Lusaka (3%-7%). Antiretroviral therapy (ART) use among HIV+ FSWs was 9%-15%. In all groups, consistent condom use (8%-11%) and modern contraceptive use (35%-65%) were low. Low literacy and reported coercion at first sexual intercourse were common in both FSWs and SMs, as was alcohol use during sex among FSWs. Zambian FSWs and SMs have low condom use and high HIV/STI and unplanned pregnancy risk. Many FSWs and half of SMs are ≥25 years of age, and thus too old for HIV prevention services targeting "adolescent girls and young women" (aged 15-24). Tailored and targeted reproductive health services are needed to reduce HIV, STI, and unplanned pregnancy in these vulnerable women.

HIV epidemiology among female sex workers and their clients in the Middle East and North Africa: systematic review, meta-analyses, and meta-regressions

BACKGROUND

HIV epidemiology among female sex workers (FSWs) and their clients in the Middle East and North Africa (MENA) region is poorly understood. We addressed this gap through a comprehensive epidemiological assessment.

METHODS

A systematic review of population size estimation and HIV prevalence studies was conducted and reported following PRISMA guidelines. Risk of bias (ROB) assessments were conducted for all included studies using various quality domains, as informed by Cochrane Collaboration guidelines. The pooled mean HIV prevalence was estimated using random-effects meta-analyses. Sources of heterogeneity and temporal trends were identified through meta-regressions.

RESULTS

We identified 270 size estimation studies in FSWs and 42 in clients, and 485 HIV prevalence studies in 287,719 FSWs and 69 in 29,531 clients/proxy populations. Most studies had low ROB in multiple quality domains. The median proportion of reproductive-age women reporting current/recent sex work was 0.6% (range = 0.2-2.4%) and of men reporting currently/recently buying sex was 5.7% (range = 0.3-13.8%). HIV prevalence ranged from 0 to 70% in FSWs (median = 0.1%) and 0-34.6% in clients (median = 0.4%). The regional pooled mean HIV prevalence was 1.4% (95% CI = 1.1-1.8%) in FSWs and 0.4% (95% CI = 0.1-0.7%) in clients. Country-specific pooled prevalence was < 1% in most countries, 1-5% in North Africa and Somalia, 17.3% in South Sudan, and 17.9% in Djibouti. Meta-regressions identified strong subregional variations in prevalence. Compared to Eastern MENA, the adjusted odds ratios (AORs) ranged from 0.2 (95% CI = 0.1-0.4) in the Fertile Crescent to 45.4 (95% CI = 24.7-83.7) in the Horn of Africa. There was strong evidence for increasing prevalence post-2003; the odds increased by 15% per year (AOR = 1.15, 95% CI = 1.09-1.21). There was also a large variability in sexual and injecting risk behaviors among FSWs within and across countries. Levels of HIV testing among FSWs were generally low. The median fraction of FSWs that tested for HIV in the past 12 months was 12.1% (range = 0.9-38.0%).

CONCLUSIONS

HIV epidemics among FSWs are emerging in MENA, and some have reached stable endemic levels, although still some countries have limited epidemic dynamics. The epidemic has been growing for over a decade, with strong regionalization and heterogeneity. HIV testing levels were far below the service coverage target of "UNAIDS 2016-2021 Strategy."

Mobility and sex work: why, where, when? A typology of female-sex-worker mobility in Zimbabwe

Sex-worker mobility may have implications for health and access to care but has not been described in sub-Saharan Africa. We described sex-worker mobility in Zimbabwe and a mobility typology using data from 2591 and 2839 female sex workers in 14 sites from 2013 and 2016. We used latent class analysis to identify a typology of mobile sex workers. More women travelled for work in 2016 (59%) than in 2013 (27%), usually to find clients with more money (57% of the journeys), spending a median of 21 (2013) and 24 (2016) days away. A five-class mixture model best fitted the data, with 39% women in an infrequent work-mobility class, 21% in a domestic-high-mobility class, 16% in an international-high-mobility class, 16% in an infrequent opportunistic-non-work-mobility class, and 7% who travel with clients. More-mobile classes were better educated; risk behaviours differed by class. Mobility is increasing among sex worker in Zimbabwe, multi-faceted, and not explained by other vulnerabilities.

High condom use but low HIV testing uptake reported by men who purchase sex in Bali, Indonesia

Men who purchase sex (MWPS) have long been considered as one of the population groups at risk of HIV transmission. However, while HIV-related interventions have been targeted towards this group, few studies have directly recruited MWPS to measure the impact of such interventions. This study aimed to fill the gap for Indonesia by identifying the level and predictors of condom use and HIV testing among MWPS, to inform prevention strategies. A cross-sectional study was conducted by surveying 200 MWPS in Bali, Indonesia in 2015. A structured questionnaire was administered to collect the data. Self-reported condom use on the occasion of last paid sex was very high (88.5%), while a history of HIV testing was low (8.1%). None of the variables identified in this study were associated with condom use at last paid sex. Men were more likely to report a history of HIV testing if they: perceived themselves to be at high risk of HIV, had a higher level of HIV-related knowledge, reported a history of genital ulcers or urethral discharge in the past 12 months, or were aware that confidential HIV testing was available. Implications and limitations of this study are discussed.

HIV Epidemic in Tanzania: The Possible Role of the Key Populations

HIV remains a public health concern in Tanzania and other Eastern and Southern African countries. Estimates show that there were about 1.4 million people living with HIV in Tanzania in the year 2013. HIV is a generalized epidemic in Tanzania with heterosexual transmission being the main route of transmission. Recently, however, there has been growing concern on the potential role of the key populations in HIV epidemic in the country. Studies done have shown significantly higher HIV prevalence in these populations compared to the general population. These studies have also reported high risky behaviors among members of these populations. This review aims at discussing the possible role of the key populations in the HIV epidemic in Tanzania.

Commercial Sexual Behaviors Among Male Rural-to-Urban Migrants in Western China: Implications for HIV Prevention

Rural-to-urban migrants are at high risk of HIV infection. The goal of this survey was to explore the commercial sexual behavior and condom use among male rural-to-urban migrants in western China. A cross-sectional survey on male rural-to-urban migrants in western China was conducted. Among all the subjects surveyed, 140 (7.4%) had commercial sexual behavior, which is associated with being aged older than 24 years, being of Han or other ethnic minorities, being divorced, separated, or widowed, having experienced drug abuse, having had heterosexual behavior, having had casual sexual partners, having had sex with a homosexual, and being from Xinjiang. A total of 31.4% of them never use condoms when buying sex. Not using condoms is associated with being from Chongqing, having a high school or above education, and having commercial sex monthly. Commercial sexual behavior and not using condoms are common among male rural-to-urban migrants in western China. Strategies and appropriate education should be developed to prevent HIV transmission due to high-risk sexual behaviors.

Sexual risk behaviors, HIV, and syphilis among female sex workers in Nepal

Purpose

Female sex workers (FSWs) are a key-affected population susceptible to acquiring HIV and sexually transmitted infections (STIs), as well as transmitting the virus to others. The aim of the study was to assess HIV and syphilis prevalence among FSWs in Nepal and to examine factors associated with it.

Materials and methods

The study was based on Integrated Biological and Behavioral Surveillance (IBBS) surveys among FSWs in Nepal from 2004 to 2015. Statistical analysis used chi-squared test to assess statistically significant risk factors for HIV and syphilis. Logistic regression models were used to identify the most important determinants for each outcome.

Results

A total of 5,958 FSWs were tested, and among them, 100 (1.7%) were HIV positive and 230 (3.9%) were syphilis positive. The multivariate analysis revealed that syphilis was higher among those street-based, aged ≥35 years, illiterate, and with a duration of sex work of >3 years. HIV was higher among those aged ≥35 years, illiterate, street-based, and with a duration of sex work >3 years. Syphilis was strongly correlated with HIV.

Conclusion

HIV epidemic among FSWs in Nepal appears in the stagnant trend, whereas STI epidemic has increased in recent years. The high influencing factors for HIV and syphilis prevalence were advanced age, street-based, lower education, and longer duration of sex work. Urgent efforts, as part of routine HIV/STI prevention and intervention, are required to reduce the high burden of syphilis among FSWs.

PrEP as a feature in the optimal landscape of combination HIV prevention in sub-Saharan Africa

Introduction

The new WHO guidelines recommend offering pre-exposure prophylaxis (PrEP) to people who are at substantial risk of HIV infection. However, where PrEP should be prioritised, and for which population groups, remains an open question. The HIV landscape in sub-Saharan Africa features limited prevention resources, multiple options for achieving cost saving, and epidemic heterogeneity. This paper examines what role PrEP should play in optimal prevention in this complex and dynamic landscape.

Methods

We use a model that was previously developed to capture subnational HIV transmission in sub-Saharan Africa. With this model, we can consider how prevention funds could be distributed across and within countries throughout sub-Saharan Africa to enable optimal HIV prevention (that is, avert the greatest number of infections for the lowest cost). Here, we focus on PrEP to elucidate where, and to whom, it would optimally be offered in portfolios of interventions (alongside voluntary medical male circumcision, treatment as prevention, and behaviour change communication). Over a range of continental expenditure levels, we use our model to explore prevention patterns that incorporate PrEP, exclude PrEP, or implement PrEP according to a fixed incidence threshold.

Results

At low-to-moderate levels of total prevention expenditure, we find that the optimal intervention portfolios would include PrEP in only a few regions and primarily for female sex workers (FSW). Prioritisation of PrEP would expand with increasing total expenditure, such that the optimal prevention portfolios would offer PrEP in more subnational regions and increasingly for men who have sex with men (MSM) and the lower incidence general population. The marginal benefit of including PrEP among the available interventions increases with overall expenditure by up to 14% (relative to excluding PrEP). The minimum baseline incidence for the optimal offer of PrEP declines for all population groups as expenditure increases. We find that using a fixed incidence benchmark to guide PrEP decisions would incur considerable losses in impact (up to 7%) compared with an approach that uses PrEP more flexibly in light of prevailing budget conditions.

Conclusions

Our findings suggest that, for an optimal distribution of prevention resources, choices of whether to implement PrEP in subnational regions should depend on the scope for impact of other possible interventions, local incidence in population groups, and total resources available. If prevention funding were to become restricted in the future, it may be suboptimal to use PrEP according to a fixed incidence benchmark, and other prevention modalities may be more cost-effective. In contrast, expansions in funding could permit PrEP to be used to its full potential in epidemiologically driven prevention portfolios and thereby enable a more cost-effective HIV response across Africa.

Connecting the dots: network data and models in HIV epidemiology

Effective HIV prevention requires knowledge of the structure and dynamics of the social networks across which infections are transmitted. These networks most commonly comprise chains of sexual relationships, but in some populations, sharing of contaminated needles is also an important, or even the main mechanism that connects people in the network. Whereas network data have long been collected during survey interviews, new data sources have become increasingly common in recent years, because of advances in molecular biology and the use of partner notification services in HIV prevention and treatment programmes. We review current and emerging methods for collecting HIV-related network data, as well as modelling frameworks commonly used to infer network parameters and map potential HIV transmission pathways within the network. We discuss the relative strengths and weaknesses of existing methods and models, and we propose a research agenda for advancing network analysis in HIV epidemiology. We make the case for a combination approach that integrates multiple data sources into a coherent statistical framework.

Seroprevalence and Co-Infection of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) Among Pregnant Women in Lokoja, North-Central Nigeria

Background

Herpes simplex virus 1 (HSV-1) is normally associated with orofacial (orolabial) infections and encephalitis, whereas HSV-2 usually causes genital infections and can be transmitted from infected mothers to neonates. The evidence suggesting that HSV is facilitating the spread of the global human immunodeficiency virus (HIV) epidemic and the risk posed by these synergies to neonates in developing countries informed this study.

Objectives

To determine the seroprevalence and co-infection of HIV and HSV, as well as their associated risk factors, in Lokoja, Nigeria.

Methods

This was a hospital-based cross-sectional, prospective study, which was carried out among pregnant women attending the antenatal clinic at the federal medical centre in Lokoja, Nigeria. sociodemographic characteristics and HIV-HSV status were determined by the use of a structured questionnaire and immunoassay kits, respectively. All data were analyzed using Stata statistical software (version 12), and the level of significance was determined to be P < 0.05 using the chi-square test.

Results

Of the 250 pregnant women screened for HIV and HSV, 154 (61.6%) were in the 2nd trimester of gestation, and all of the co-infected respondents were in their 2nd trimester. Only six (2.4%) of the respondents tested positive for HIV, with all six (100%) showing positivity for HSV so the co-infection rate was six (2.4%). Co-infection was found to occur between the ages of 15 and 35 years, while higher age groups did not show any co-infection. Parity, level of education, and history of painful genital ulcers had no significant association with co-infection.

Conclusions

Advocacy and publicity to raise awareness of the potential public health impact of HSV and HIV co-infection in Nigeria, where anti-HSV testing is not generally performed in all populations, is therefore recommended.

Factors Associated with Variations in Population HIV Prevalence across West Africa: Findings from an Ecological Analysis

BACKGROUND

Population HIV prevalence across West Africa varies substantially. We assess the national epidemiological and behavioural factors associated with this.

METHODS

National, urban and rural data on HIV prevalence, the percentage of younger (15-24) and older (25-49) women and men reporting multiple (2+) partners in the past year, HIV prevalence among female sex workers (FSWs), men who have bought sex in the past year (clients), and ART coverage, were compiled for 13 countries. An Ecological analysis using linear regression assessed which factors are associated with national variations in population female and male HIV prevalence, and with each other.

FINDINGS

National population HIV prevalence varies between 0 4-2 9% for men and 0 4-5.6% for women. ART coverage ranges from 6-23%. National variations in HIV prevalence are not shown to be associated with variations in HIV prevalence among FSWs or clients. Instead they are associated with variations in the percentage of younger and older males and females reporting multiple partners. HIV prevalence is weakly negatively associated with ART coverage, implying it is not increased survival that is the cause of variations in HIV prevalence. FSWs and younger female HIV prevalence are associated with client population sizes, especially older men. Younger female HIV prevalence is strongly associated with older male and female HIV prevalence.

INTERPRETATION

In West Africa, population HIV prevalence is not significantly higher in countries with high FSW HIV prevalence. Our analysis suggests, higher prevalence occurs where more men buy sex, and where a higher percentage of younger women, and older men and women have multiple partnerships. If a sexual network between clients and young females exists, clients may potentially bridge infection to younger females. HIV prevention should focus both on commercial sex and transmission between clients and younger females with multiple partners.

Implementation of an electronic fingerprint-linked data collection system: a feasibility and acceptability study among Zambian female sex workers

Background

Patient identification within and between health services is an operational challenge in many resource-limited settings. When following HIV risk groups for service provision and in the context of vaccine trials, patient misidentification can harm patient care and bias trial outcomes. Electronic fingerprinting has been proposed to identify patients over time and link patient data between health services. The objective of this study was to determine 1) the feasibility of implementing an electronic-fingerprint linked data capture system in Zambia and 2) the acceptability of this system among a key HIV risk group: female sex workers (FSWs).

Methods

Working with Biometrac, a US-based company providing biometric-linked healthcare platforms, an electronic fingerprint-linked data capture system was developed for use by field recruiters among Zambian FSWs. We evaluated the technical feasibility of the system for use in the field in Zambia and conducted a pilot study to determine the acceptability of the system, as well as barriers to uptake, among FSWs.

Results

We found that implementation of an electronic fingerprint-linked patient tracking and data collection system was feasible in this relatively resource-limited setting (false fingerprint matching rate of 1/1000 and false rejection rate of <1/10,000) and was acceptable among FSWs in a clinic setting (2 % refusals). However, our data indicate that less than half of FSWs are comfortable providing an electronic fingerprint when recruited while they are working. The most common reasons cited for not providing a fingerprint (lack of privacy/confidentiality issues while at work, typically at bars or lodges) could be addressed by recruiting women during less busy hours, in their own homes, in the presence of “Queen Mothers” (FSW organizers), or in the presence of a FSW that has already been fingerprinted.

Conclusions

Our findings have major implications for key population research and improved health services provision. However, more work needs to be done to increase the acceptability of the electronic fingerprint-linked data capture system during field recruitment. This study indicated several potential avenues that will be explored to increase acceptability.

Sexual violence, condom negotiation, and condom use in the context of sex work: results from two West African countries

BACKGROUND

Female sex workers (FSWs) are vulnerable to violence within and beyond the workplace. Violence is associated with increased burden of HIV, possibly explained through physiologic or behavioral causal pathways. These analyses sought to determine the relationship between lifetime sexual violence with unprotected, condomless vaginal intercourse (UVI) among FSWs in West Africa.

METHODS

FSWs (aged ≥18 years) were recruited into a cross-sectional study through respondent-driven sampling in two West African countries, Togo and Burkina Faso. A total of 1380 participants were enrolled from January to July 2013, and completed a sociobehavioral questionnaire and HIV testing. Measures included sex work history, lifetime experiences of violence victimization, sexual practices, and UVI (past month). Crude and adjusted robust log binomial regression was conducted to estimate prevalence ratios (PrR) as a measure of association between UVI with clients and the primary exposure, forced sex.

RESULTS

Self-reported lifetime physical abuse (47.3%), forced sex (33.0%), and any violence (57.9%) were common. Almost one-quarter (23.9%) reported recent UVI with clients. History of forced sex was independently associated with recent UVI with clients [vs. none, adjusted PrR: 1.49; 95% confidence interval (CI): 1.18 to 1.88], with evidence of partial mediation by difficult condom negotiation with regular (aPrR: 1.83; 95% CI: 1.43 to 2.34) and new clients (aPrR: 1.60; 95% CI: 1.13 to 2.29).

DISCUSSION

These data demonstrate the significant relationship between sexual violence experienced by FSWs and unprotected sex with clients. Comprehensive interventions reducing vulnerabilities to violence combined with improved condom negotiation are needed to address the complex influences of condom use during sex work as a means of ultimately lowering HIV acquisition and transmission.

A qualitative study of discourses on heterosexual anal sexual practice among key, and general populations in Tanzania: implications for HIV prevention

Background

The risk of contracting HIV through heterosexual anal sex (HAS) is significantly higher than from vaginal intercourse. Little has been done to understand the discourses around HAS and terms people use to describe the practice in Tanzania. A better understanding of discourses on HAS would offer useful insights for measurement of the practice as well as designing appropriate interventions to minimise the risks inherent in the practice.

Methods

This study employed qualitative approaches involving 24 focus group discussions and 81 in-depth interviews. The study was conducted in 4 regions of Tanzania, and included samples from the general population and among key population groups (fishermen, truck drivers, sex workers, food and recreational facilities workers). Discourse analysis was conducted with the aid of NVIVO versions 8 and 10 software.

Results

Six discourses were delineated in relation to how people talked about HAS. Secrecy versus openness discourse describes the terms used when talking about HAS. “Other” discourse involved participants’ perception of HAS as something practiced by others unrelated to them and outside their communities. Acceptability/trendiness discourse: young women described HAS as something trendy and increasingly gaining acceptability in their communities. Materiality discourse: describes HAS as a practice that was more profitable than vaginal sex. Masculinity discourse involved discussions on men proving their manhood by engaging in HAS especially when women initiated the practice. Masculine attitudes were also reflected in how men described the practice using a language that would be considered crude. Public health discourse: describes HAS as riskier for HIV infection than vaginal sex. The reported use of condoms was low due to the perceptions that condoms were unsuitable for anal sex, but also perceptions among some participants that anal sex was safer than vaginal sex.

Conclusion

Discourses among young women and adult men across the study populations were supportive of HAS. These findings provide useful insights in understanding how different population groups talked about HAS and offer a range of terms that interventions and further research on magnitude of HAS could draw on when addressing health risks of HAS among different study populations.

Estimating the number of sex workers in South Africa: rapid population size estimation

Although recognized as a vulnerable population, there is no national population size estimate for sex workers in South Africa. A rapid sex worker enumeration exercise was undertaken in twelve locations across the country based on principles of participatory mapping and Wisdom of the Crowd. Sites with a range of characteristics were selected, focusing on level of urbanisation, trucking, mining and borders. At each site, sex worker focus groups mapped local hotspots. Interviews with sex workers at identified hotspots were used to estimate the numbers and genders of sex workers working in each. Estimates provided in the literature were combined with enumeration exercise results to define assumptions that could be applied to a national extrapolation. A working estimate was reached of between 131,000 and 182,000 sex worker in South Africa, or between 0.76 and 1 % of the adult female population. The success of the exercise depended on integral involvement of sex worker peer educators and strong ethical considerations.

Poverty, food insufficiency and HIV infection and sexual behaviour among young rural Zimbabwean women

Background

Despite a recent decline, Zimbabwe still has the fifth highest adult HIV prevalence in the world at 14.7%; 56% of the population are currently living in extreme poverty.

Design

Cross-sectional population-based survey of 18–22 year olds, conducted in 30 communities in south-eastern Zimbabwe in 2007.

Objective

To examine whether the risk of HIV infection among young rural Zimbabwean women is associated with socio-economic position and whether different socio-economic domains, including food sufficiency, might be associated with HIV risk in different ways.

Methods

Eligible participants completed a structured questionnaire and provided a finger-prick blood sample tested for antibodies to HIV and HSV-2. The relationship between poverty and HIV was explored for three socio-economic domains: ability to afford essential items; asset wealth; food sufficiency. Analyses were performed to examine whether these domains were associated with HIV infection or risk factors for infection among young women, and to explore which factors might mediate the relationship between poverty and HIV.

Results

2593 eligible females participated in the survey and were included in the analyses. Overall HIV prevalence among these young females was 7.7% (95% CI: 6.7–8.7); HSV-2 prevalence was 11.2% (95% CI: 9.9–12.4). Lower socio-economic position was associated with lower educational attainment, earlier marriage, increased risk of depression and anxiety disorders and increased reporting of higher risk sexual behaviours such as earlier sexual debut, more and older sexual partners and transactional sex. Young women reporting insufficient food were at increased risk of HIV infection and HSV-2.

Conclusions

This study provides evidence from Zimbabwe that among young poor women, economic need and food insufficiency are associated with the adoption of unsafe behaviours. Targeted structural interventions that aim to tackle social and economic constraints including insufficient food should be developed and evaluated alongside behaviour and biomedical interventions, as a component of HIV prevention programming and policy.

Positive impact of increases in condom use among female sex workers and clients in a medium HIV prevalence epidemic: modelling results from Project SIDA1/2/3 in Cotonou, Benin

BACKGROUND

A comprehensive, HIV prevention programme (Projet Sida1/2/3) was implemented among female sex workers (FSWs) in Cotonou, Benin, in 1993 following which condom use among FSWs increased threefold between 1993 and 2008 while FSW HIV prevalence declined from 53.3% to 30.4%.

OBJECTIVE

Estimate the potential impact of the intervention on HIV prevalence/incidence in FSWs, clients and the general population in Cotonou, Benin.

METHODS AND FINDINGS

A transmission dynamics model parameterised with setting-specific bio-behavioural data was used within a Bayesian framework to fit the model and simulate HIV transmission in the high and low-risk population of Cotonou and to estimate HIV incidence and infections averted by SIDA1/2/3. Our model results suggest that prior to SIDA1/2/3 commercial sex had contributed directly or indirectly to 93% (84-98%) of all cumulative infections and that the observed decline in FSWs HIV prevalence was more consistent with the self-reported post-intervention increase in condom use by FSWs than a counterfactual assuming no change in condom use after 1993 (CF-1). Compared to the counterfactual (CF-1), the increase in condom use may have prevented 62% (52-71%) of new HIV infections among FSWs between 1993 and 2008 and 33% (20-46%) in the overall population.

CONCLUSIONS

Our analysis provides plausible evidence that the post-intervention increase in condom use during commercial sex significantly reduced HIV prevalence and incidence among FSWs and general population. Sex worker interventions can be effective even in medium HIV prevalence epidemics and need to be sustained over the long-term.

Validation of the modes of transmission model as a tool to prioritize HIV prevention targets: a comparative modelling analysis

Background

The static Modes of Transmission (MOT) model predicts the annual fraction of new HIV infections acquired across subgroups (MOT metric), and is used to focus HIV prevention. Using synthetic epidemics via a dynamical model, we assessed the validity of the MOT metric for identifying epidemic drivers (behaviours or subgroups that are sufficient and necessary for HIV to establish and persist), and the potential consequence of MOT-guided policies.

Methods and Findings

To generate benchmark MOT metrics for comparison, we simulated three synthetic epidemics (concentrated, mixed, and generalized) with different epidemic drivers using a dynamical model of heterosexual HIV transmission. MOT metrics from generic and complex MOT models were compared against the benchmark, and to the contribution of epidemic drivers to overall HIV transmission (cumulative population attributable fraction over t years, PAF_t). The complex MOT metric was similar to the benchmark, but the generic MOT underestimated the fraction of infections in epidemic drivers. The benchmark MOT metric identified epidemic drivers early in the epidemics. Over time, the MOT metric did not identify epidemic drivers. This was not due to simplified MOT models or biased parameters but occurred because the MOT metric (irrespective of the model used to generate it) underestimates the contribution of epidemic drivers to HIV transmission over time (PAF_5–30). MOT-directed policies that fail to reach epidemic drivers could undermine long-term impact on HIV incidence, and achieve a similar impact as random allocation of additional resources.

Conclusions

Irrespective of how it is obtained, the MOT metric is not a valid stand-alone tool to identify epidemic drivers, and has limited additional value in guiding the prioritization of HIV prevention targets. Policy-makers should use the MOT model judiciously, in combination with other approaches, to identify epidemic drivers.

Acceptability of oral and topical HIV chemoprophylaxis in India: implications for at-risk women and men who have sex with men

With reducing HIV prevalence, India has made gains in containing the epidemic. Yet, unprotected sex and commercial sex work, unprotected anal sex between men and needle sharing among intravenous drug users continue to drive the epidemic. Development of effective, safe and acceptable topical (microbicides) and oral (pre-exposure prophylaxis (PrEP)) chemoprophylaxis could augment the already available tools for HIV prevention. This paper reviews the acceptability of topical microbicides and oral PrEP, in the context of the nature of the HIV epidemic, the sociocultural norms and the acceptability data obtained from studies carried out in India. Overall, men and women have a positive attitude towards the concept and use of microbicide products. Self-perceptions of HIV risk, product attributes, ease and convenience of use during sex, gender norms, the sociocultural context and the potential for undisclosed use were important factors influencing acceptability. A multipurpose product that would simultaneously address women's contraceptive and disease prevention needs would be devoid of the stigma attached to an anti-HIV product and may be more acceptable. Limited information on the acceptability of oral PrEP amongst high-risk groups merits further research, including carrying out demonstration projects for program introduction.

Epidemiology of HIV among female sex workers, their clients, men who have sex with men and people who inject drugs in West and Central Africa

Introduction

The West and Central Africa (WCA) sub-region is the most populous region of sub-Saharan Africa (SSA), with an estimated population of 356 million living in 24 countries. The HIV epidemic in WCA appears to have distinct dynamics compared to the rest of SSA, being more concentrated among key populations such as female sex workers (FSWs), men who have sex with men (MSM), people who inject drugs (PWID) and clients of FSWs. To explore the epidemiology of HIV in the region, a systematic review of HIV literature among key populations in WCA was conducted since the onset of the HIV epidemic.

Methods

We searched the databases PubMed, CINAHL and others for peer-reviewed articles regarding FSWs, MSM and PWID in 24 countries with no date restriction. Inclusion criteria were sensitive and focused on inclusion of any HIV prevalence data among key populations. HIV prevalence was pooled, and in each country key themes were extracted from the literature.

Results

The search generated 885 titles, 214 abstracts and 122 full articles, of which 76 met inclusion and exclusion criteria providing HIV prevalence data. There were 60 articles characterizing the burden of disease among FSWs, eight for their clients, one for both, six for MSM and one for PWID. The pooled HIV prevalence among FSWs was 34.9% (n=14,388/41,270), among their clients was 7.3% (n=435/5986), among MSM was 17.7% (n=656/3714) and among PWID from one study in Nigeria was 3.8% (n=56/1459).

Conclusions

The disproportionate burden of HIV among FSWs appears to be consistent from the beginning of the HIV epidemic in WCA. While there are less data for other key populations such as clients of FSWs and MSM, the prevalence of HIV is higher among these men compared to other men in the region. There have been sporadic reports among PWID, but limited research on the burden of HIV among these men and women. These data affirm that the HIV epidemic in WCA appears to be far more concentrated among key populations than the epidemics in Southern and Eastern Africa. Evidence-based HIV prevention, treatment and care programmes in WCA should focus on engaging populations with the greatest burden of disease in the continuum of HIV care.

Trichomonas vaginalis is highly prevalent in adolescent girls, pregnant women, and commercial sex workers in Ndola, Zambia

OBJECTIVES

The aim of the study was to assess the prevalence of Trichomonas sp. infection among adolescent girls, pregnant women, and commercial sex workers in Ndola, Zambia.

METHODS

A cross-sectional study was conducted among 460 girls attending school, 307 pregnant women, and 197 commercial sex workers. Self-collected specimens from the vagina, rectum, and mouth were tested by polymerase chain amplification assays for the presence of Trichomonas vaginalis, Pentatrichomonas hominis, and Trichomonas tenax. Genotyping was performed on specimens that tested positive for T. vaginalis.

RESULTS

The prevalence of vaginal infection with T. vaginalis was 24.6% among the adolescents, 32.2% among the pregnant women, and 33.2% among the commercial sex workers. Trichomonads other than T. vaginalis were rarely found in the vagina, rectum, and mouth. The presence of T. vaginalis in the rectum was associated with T. vaginalis in the vagina. T. tenax was also detected in the vagina. A total of 9 actin genotypes of T. vaginalis were identified. The distribution of the actin genotypes of T. vaginalis was similar in the 3 study groups.

CONCLUSION

We detected high prevalence rates of trichomoniasis among women in Ndola, Zambia. Prevalence among adolescent girls was lower than among pregnant women and commercial sex workers but was still high. We were not able to detect differences in T. vaginalis actin genotypes among the 3 study groups.

Commercial sex and condom use among involuntary bachelors: an exploratory survey in rural China

In the present context of the Chinese male marriage squeeze, commercial sex is becoming an important way for bachelors to meet their sexual needs. Using data from a survey conducted in a rural district of Anhui province, China, this study analyzes commercial sex experiences and condom use among involuntary bachelors and compares usage in this population to that observed in married men in the same age groups. Our findings indicate that, for both first and most recent sexual intercourse, the prevalence of commercial sex among unmarried men is significantly higher than that reported among married men; indeed, marital status was the only variable that was consistently related to rates of commercial sex for both first and most recent sexual intercourse. The vast majority of sexual intercourse was still unprotected, and the rate of condom use was not only lower among unmarried men than among married men, but was also significantly related to knowledge of sexually transmitted diseases, as well as age, education, and income. Because of their lower condom use, unmarried men face much higher risks of contracting and spreading sexually transmitted diseases than married men do. This situation poses a severe threat to public health.

An integrated individual, community, and structural intervention to reduce HIV/STI risks among female sex workers in China

Background

We assessed the effectiveness of an integrated individual, community, and structural intervention to reduce risks of HIV and sexually transmitted infections (STIs) among female sex workers (FSWs).

Methods

The integration individual, community, and structural intervention was implemented from 2004 to 2009 in six counties of Shandong Province. Post-intervention cross-sectional surveys were conducted in six intervention counties and 10 control counties.

Results

Of 3326 female sex workers were recruited and analyzed in the post-intervention survey with 1157 from intervention sites and 2169 from control sites. No HIV positive was found in both intervention and control counties. The rate of syphilis was 0.17% for intervention sites and 1.89% for control sites (OR = 11.1, 95% CI: 2.7, 46.1). After adjusted for age, marital status, education, economic condition, recruitment venues, the rates of condom use in the last sex with clients(AOR = 2.7; 95% CI: 1.9, 3.8), with regular sex partners(AOR = 1.5; 95% CI: 1.1, 1.9) and consistent condom use in the last month with clients (AOR = 3.3; 95% CI: 2.6, 4.1) and regular sex partners (AOR = 1.7; 95% CI: 1.3, 2.3) were significantly higher in intervention sites than that in control sites. The proportion of participants correctly answered at least six out of eight HIV-related questions (83.3%) in intervention sites is significant higher than that (21.9%) in control sites (AOR = 24.7; 95% CI: 2.5, 42.7), the five indicators related to HIV-related intervention services ever received in the last year including HIV testing(AOR = 4.9; 95% CI: 2.8, 6.7), STD examination and/or treatment(AOR = 5.1; 95% CI: 4.2, 6.4), free condom(AOR = 20.3; 95% CI: 14.3, 28.9), peer education(AOR = 4.3; 95% CI: 3.5, 5.4), education materials(AOR = 19.8; 95%CI: 13.1, 29.8) were significantly higher in intervention sites than that in control sites, the participants in the intervention sites are more likely to seek medical treatment when they had any disorders (AOR = 3.2; 95% CI: 2.5, 4.2).

Conclusion

This study found that the integrated individual, community, and structural intervention showed positive impact in reducing HIV and STI risks among FSWs.

Decline in the prevalence of HIV and sexually transmitted infections among female sex workers in Benin over 15 years of targeted interventions

BACKGROUND

An HIV-preventive intervention targeting the sex work milieu and involving fully integrated components of structural interventions, communication for behavioral change and care for sexually transmitted infections (STIs), was implemented in Benin by a Canadian project from 1992 to 2006. It first covered Cotonou before being extended to other main cities from 2000. At the project end, the Beninese authorities took over the intervention, but structural interventions were interrupted and other intervention components were implemented separately. We estimated time trends in HIV/STI prevalence among female sex workers (FSWs) from 1993 to 2008 and assessed the impact of the change in intervention model on trends.

METHODS

Six integrated biological and behavioral surveys were carried out among FSWs. Time trend analysis controlled for potential sociodemographic confounders using log-binomial regression.

RESULTS

In Cotonou, from 1993 to 2008, there was a significant decrease in HIV (53.3%-30.4%), gonorrhea (43.2%-6.4%), and chlamydia (9.4%-2.8%) prevalence (all adjusted P = 0.0001). The decrease in HIV and gonorrhea prevalence was also significant in the other cities between 2002 and 2008. In 2002, gonorrhea prevalence was lower in Cotonou than elsewhere (prevalence ratio = 0.53, 95% confidence interval: 0.32 to 0.88). From 2005 to 2008, there was an increase in gonorrhea prevalence (prevalence ratio = 1.76, 95% confidence interval: 1.17 to 2.65) in all cities combined.

CONCLUSIONS

Our results suggest a significant impact of this targeted preventive intervention on HIV/STI prevalence among FSWs. The recent increase in gonorrhea prevalence could be related to the lack of integration of the intervention components.

Cohort Profile: The Likoma Network Study (LNS)

The Likoma network study (LNS) investigates the sexual networks connecting the inhabitants of Likoma, a small island of Lake Malawi with high HIV prevalence. Whereas previous studies of sexual networks and HIV/AIDS in sub-Saharan countries have focused solely on the personal networks of a small number of respondents, the LNS attempts to document the sexual networks of the entire adult population of Likoma. To do so, it uses a unique sociocentric study design, in which all members of the local population are contacted for a survey interview and are asked to nominate their five most recent sexual partners. Using these data, quasi-complete 'maps' of the sexual networks connecting inhabitants of the island can be constructed. These maps allow investigation of the impact of networks on HIV epidemiology and can inform mathematical models of HIV prevention. In addition to data on sexual networks, the LNS data include information on the social networks (e.g. friendship), socioeconomic characteristics and HIV status of Likoma's residents. Baseline data were collected in 2005-06. A first follow-up was conducted in 2007-08 and a second follow-up is planned for early 2013. Access to the LNS data is contingent upon review of a short concept paper and forming collaborations with LNS investigators.

Drug use and sex work: competing risk factors for newly acquired HIV in Yunnan, China

Objective

To investigate the HIV incidence and its related factors among female sex workers (FSWs) in a high prevalence area where injection drug use is also widely documented.

Method

A cross-sectional study of 1642 female sex workers (FSWs) was conducted in Honghe Prefecture of Yunnan Province. Interviewed-questionnaires were administrated to collect information on sexual partnerships, condom use and illicit drug using behaviors etc. Blood samples were collected to test for HIV antibodies, and all HIV seropositive specimens were tested with the BED IgG capture-based enzyme immunosorbent assay (BED-CEIA) to distinguish between new and established HIV infection (<153 days).

Results

15.9% (261/1642) of participants reported ever having used drugs, and 7.4% had injected in recent 3 months. The overall HIV prevalence was 10.2% (168/1642), among which 16.7% (28/168) were identified as recent infections using BED-CEIA. The crude HIV incidence estimated from BED-CEIA results was 4.4 (95%CI 2.8–6.0) /100 person years (PY). Multivariate logistic analysis showed that an illicit drug using history (by either self-reporting or urine opiates testing) was both significant risk factors both for HIV established and recent infection (each p<0.05). Drug using FSWs (DU-FSW) reported more male clients in the previous week, and had significantly higher prevalence of HIV, chlamydia trachomatis and HSV-2 as compared to non DU-FSW (each p<0.05).

Conclusion

Our results show that a history of drug use poses significant risks for both new and established HIV infection among FSWs, and that HIV-incidence among Honghe FSWs is relatively high compared to similar populations. Comprehensive interventions targeted at DU-FSWs' injection drug using and high risk sexual behaviors are urgently needed to reduce the rapid spread of HIV epidemic.

Prevalence of HIV and other sexually transmitted infections among female sex workers in Kisumu, Western Kenya, 1997 and 2008

Background

In 1997, a survey in Kisumu found a prevalence of HIV infection among female sex workers (FSW) of 75%. Only 50% reported using a condom with the last client. In 2008, we conducted another survey to collect data to inform an intervention targeting FSW in Kisumu.

Methods

In 2008 FSW were recruited by respondent-driven sampling. Women completed a questionnaire and were tested for HIV and other sexually transmitted infections (STIs). Multiple logistic regression analysis was done to explore factors associated with HIV-infection, and with condom use. Prevalence of HIV infection was compared in the two surveys from 1997 and 2008. Multivariate analysis was used to assess whether a change in HIV prevalence between the two surveys could be explained by changes in socio-demographic characteristics and/or behavioral factors.

Results

481 FSW participated in the 2008 study. HIV prevalence was 56.5% (95% CI 52.0–61.6). Factors independently associated with HIV were age older than 29 years; being a widow; STI treatment in the past year; herpes simplex virus Type-2 infection; bacterial vaginosis; and trichomoniasis. Condom use with last client was reported by 75.0% (95% CI 70.9–78.9). Predictors of condom use with the last client were age older than 29 years; higher price paid by last client; ever having been tested for HIV. Predictors of unprotected sex were being drunk during last sex act; usually having sex during menses; and STI treatment in the past year. The odds ratio of HIV infection associated with year of survey was 0.49 (95% CI 0.33–0.75) after adjusting for socio-demographic and behavioral factors.

Conclusions

The prevalence of HIV among FSW in Kisumu was found to be lower in 2008 than in 1997, while reported condom use was higher. However, access to HIV/STI prevention and care services needs to improve to further decrease HIV transmission between FSW and their clients.

Trends in risk behaviors among female sex workers in south India: priorities for sustaining the reversal of HIV epidemic

HIV epidemic in India is predominantly concentrated in subgroups of population, such as female sex workers (FSWs) and their clients, whose behavior exposes them to a higher risk of acquiring HIV infection. This paper aims to present the changing patterns of socio-demographic characteristics, behaviors, reported sexually transmitted infections (STIs), and associated factors among FSWs over 11 years. Multistage cluster sampling with probability-proportional-to-size (PPS) method was used in the surveys. A sample of 400 FSWs was studied every year. The mean age and literacy at the baseline level increased significantly over the years. House-based sex increased by 40% from 43.3% in 1997 to 83% in 2008 (p<0.001). Condom use at last sex with one-time clients; consistent condom use (CCU) with one-time and regular clients indicated increasing trends. FSWs reported low levels of condom use at last sex (14.5% in 1997 to 5% in 2008; p<0.001) and CCU (12.6% in 2004 to 3.6% in 2008; p<0.01) with regular partners. FSWs who used condom with one-time clients at last sex reported significantly less STI symptoms. A two-third reduction in genital ulcers was found from 13.1% in 1997 to 4.5% in 2008 (p<0.001). Nonliterate and hotel-based sex workers were 1.6 (1.0-2.5; 95% CI) and 2.2(1.3-3.7; 95% CI) times more likely to have reported STI symptoms. The percentage of FSWs who underwent HIV testing increased (p<0.001); similarly, a 20% increase was found in FSWs who availed counseling services from 65.2% in 1997 to 85.4% in 2008 (p<0.001). Poor, illiterate, and marginalized were more likely to get involved in risky behaviors which suggest the need for structural interventions as part of HIV prevention strategy.

HIV risk behaviors differ by workplace stability among Mexican female sex workers with truck driver clientele

Background

In a study of female sex workers (FSWs) servicing truck driver clients in Mexican border cities, we evaluated differences in HIV/STI risk behaviours determined by workplace.

Design and Methods

Our study was cross-sectional and its population comprised 100 FSWs from Nuevo Laredo (US border) and 100 FSWs from Ciudad Hidalgo (Guatemalan border). The main outcome was primary place of sex work defined as unstable (street, vehicle, gas station, etc.) vs stable (bar, brothel, and hotel). Logistic regression was used to identify correlates associated with trading sex at unstable workplaces in the last month.

Results

Of the FSWs surveyed, 18% reported an unstable workplace. The majority of FSWs surveyed were young (<30 years), single, had <9^th grade education, and had worked in the sex trade for a median of 4.9 years. After controlling for study site, FSWs with unstable vs stable workplaces were more likely to have a majority/all truck driver clientele, but were less likely to have visited a gynaecologist in the last year (OR 0.1, 95% CI 0.03-0.4) or ever had an HIV test (OR 0.1, 95% CI 0.06-0.3), and there was a trend towards lower condom use self-efficacy scores (OR 0.8 per unit increase, 95% CI 0.7-1.0). On multivariate regression, unstable workplace was associated with having majority/all truck driver clientele, being surveyed in Nuevo Laredo, and decreased odds of ever having an HIV test.

Conclusions

Among Mexican FSWs with truck driver clients, providing safe indoor spaces for sex work may help facilitate public health interventions that improve HIV/STI prevention and reproductive health outcomes.

Condom use, intervention service utilization and HIV knowledge among female sex workers in China: results of three consecutive cross-sectional surveys in Shandong Province with historically low HIV prevalence

Heterosexual transmission of HIV through contact with female sex workers (FSWs) is a growing concern for the HIV/AIDS epidemic in China. Using consecutive cross-sectional surveys, we examined the prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, HIV knowledge and the utilization of intervention services among FSWs in Shandong Province. Of 3460 participants, half reported ever having STI-related symptoms, 57.8% had ≥7 clients in the last week, half reported inconsistent use of condoms with clients and 11.2% reported ever using illicit drugs. Consistent use of condoms with clients was associated with higher education, being 20-24 years of age, being recruited from hotels, having ever received free condoms and was inversely associated with STI-related symptoms. HIV-related knowledge was associated with higher education, ever testing for HIV and inversely associated with self-reported STI-related symptoms. The low rates of condom use, high number and frequent turnover of clients, high prevalence of self-reported STIs and drug use highlight the urgency for more effective intervention in these FSWs.

Gender inequity in the lives of women involved in sex work in Kampala, Uganda

Background

Gender inequity is manifested in the social and economic burden women carry in relation to men. We investigate women's experiences of gender relations from childhood to adult life and how these may have led to and kept women in sex work.

Methods

Participants were drawn from an ongoing epidemiological cohort study of women working in high HIV/STI risk environments in Kampala. From over 1000 enrolled women, we selected 101 for a qualitative sub-study. This analysis focuses on 58 women who engaged in sex work either as a main job or as a side job. In-depth life history interviews were conducted to capture points of vulnerability that enhance gender inequity throughout their lives.

Results

Most participants were young, single parents, poorly educated, who occupied low skilled and poorly paying jobs. All women knew their HIV status and they disclosed this in the interview; 31 were uninfected while 27 said they were infected. Parental neglect in childhood was reported by many. Participants described experiences of violence while growing up sometimes perpetuated by relatives and teachers. Early unwanted pregnancies were common and for many led to leaving school. Some women stated a preference for multiple and short-term money-driven sexual relationships. Needing to earn money for child care was often the main reason for starting and persisting with sex work. Violence perpetrated by clients and the police was commonly reported. Alcohol and drug use was described as a necessary “evil” for courage and warmth, but sometimes this affected clear decision making. Many felt powerless to bargain for and maintain condom use. Leaving sex work was considered but rarely implemented.

Conclusions

Inequities in gender and power relations reduce economic and social opportunities for better lives among women and increase risky sexual behaviour. Interventions focused on these inequities that also target men are crucial in improving safer practices and reducing risk.

Socio-demographic characteristics and behavioral risk factors of female sex workers in sub-saharan Africa: a systematic review

Sex work remains an important contributor to HIV transmission within early, advanced and regressing epidemics in sub-Saharan Africa, but its social and behavioral underpinnings remain poorly understood, limiting the impact of HIV prevention initiatives. This article systematically reviews the socio-demographics of female sex workers (FSW) in this region, their occupational contexts and key behavioral risk factors for HIV. In total 128 relevant articles were reviewed following a search of Medline, Web of Science and Anthropological Index. FSW commonly have limited economic options, many dependents, marital disruption, and low education. Their vulnerability to HIV, heightened among young women, is inextricably linked to the occupational contexts of their work, characterized most commonly by poverty, endemic violence, criminalization, high mobility and hazardous alcohol use. These, in turn, predict behaviors such as low condom use, anal sex and co-infection with other sexually transmitted infections. Sex work in Africa cannot be viewed in isolation from other HIV-risk behaviors such as multiple concurrent partnerships-there is often much overlap between sexual networks. High turn-over of FSW, with sex work duration typically around 3 years, further heightens risk of HIV acquisition and transmission. Targeted services at sufficiently high coverage, taking into account the behavioral and social vulnerabilities described here, are urgently required to address the disproportionate burden of HIV carried by FSW on the continent.

HIV type 1 subtype distribution, multiple infections, sexual networks, and partnership histories in female sex workers in Kampala, Uganda

We investigated for the first time the subtype distribution, prevalence of multiple HIV-1 infections, sexual networks, and partnership histories in a cohort of women engaged in high-risk sexual behavior such as female sex workers (FSWs) and women employed in entertainment facilities. Viral RNA was extracted from blood samples collected from 324 HIV-1-positive women; the gp-41 and pol-IN genes were directly sequenced. Women found to have closely related viruses and those with recombinant viruses were further analyzed in the pol-IN gene by clonal sequencing to determine HIV-1 multiple infections. Individual partnership histories were used to provide information on when sex work was undertaken and where. Subtyping in both gp-41 and pol-IN was successfully done in 210/324 (64.8%) women. Subtype distribution in these two genes was 54.3% (n=114) A/A, 2.9% (n=6) C/C, 24.3% (n=51) D/D, 11.9% (n=25) A/D, 4.8% (n=10) D/A, 0.5% (n=1) C/A, 1.0% (n=2) B/A, and 0.5% (n=1) B/D. Sexual networks were identified in six pairs and one triplet of women with closely related subtype A viruses. Partnership histories showed that women having phylogenetically similar viruses had worked in the same localities. Five cases of multiple infections were confirmed: four dual infections and one triple infection. In this first molecular epidemiology study among FSWs in Kampala, subtype A was the predominant subtype. About 9% of a subgroup had multiple infections. Partnership histories and multiple infections observed in this population suggest sexual mixing of the FSWs and their clients confirming their high-risk characteristics.

Variable effect of co-infection on the HIV infectivity: within-host dynamics and epidemiological significance

Background

Recent studies have implicated viral characteristics in accounting for the variation in the HIV set-point viral load (spVL) observed among individuals. These studies have suggested that the spVL might be a heritable factor. The spVL, however, is not in an absolute equilibrium state; it is frequently perturbed by immune activations generated by co-infections, resulting in a significant amplification of the HIV viral load (VL). Here, we postulated that if the HIV replication capacity were an important determinant of the spVL, it would also determine the effect of co-infection on the VL. Then, we hypothesized that viral factors contribute to the variation of the effect of co-infection and introduce variation among individuals.

Methods

We developed a within-host deterministic differential equation model to describe the dynamics of HIV and malaria infections, and evaluated the effect of variations in the viral replicative capacity on the VL burden generated by co-infection. These variations were then evaluated at population level by implementing a between-host model in which the relationship between VL and the probability of HIV transmission per sexual contact was used as the within-host and between-host interface.

Results

Our within-host results indicated that the combination of parameters generating low spVL were unable to produce a substantial increase in the VL in response to co-infection. Conversely, larger spVL were associated with substantially larger increments in the VL. In accordance, the between-host model indicated that co-infection had a negligible impact in populations where the virus had low replicative capacity, reflected in low spVL. Similarly, the impact of co-infection increased as the spVL of the population increased.

Conclusion

Our results indicated that variations in the viral replicative capacity would influence the effect of co-infection on the VL. Therefore, viral factors could play an important role driving several virus-related processes such as the increment of the VL induced by co-infections. These results raise the possibility that biological differences could alter the effect of co-infection and underscore the importance of identifying these factors for the implementation of control interventions focused on co-infection.

High acceptability of HIV voluntary counselling and testing among female sex workers: impact of individual and social factors

OBJECTIVES

Voluntary counselling and testing (VCT) for HIV infection is an important tool for prevention of HIV infection and AIDS in high-risk groups. Our goal was to describe the acceptability and consequences of VCT among a stigmatized and vulnerable group, female sex workers (FSWs), in Conakry, Guinea.

METHODS

Acceptance of the test and return for test results at baseline and consequences of testing 1 year later were described. The perceived risk of HIV infection and perceived benefits and barriers to testing were examined using quantitative and qualitative methods.

RESULTS

All 421 FSW participants agreed to undergo VCT and most participants (92%) returned for their results. The main reason cited for VCT acceptance was the wish to know their HIV status. However, some managers of FSW worksites urged FSWs to be tested, curtailing FSWs' free decision-making. One year later, status disclosure was common (90% of the 198 individuals who knew their results among those who participated in the follow-up part of the study). Positive consequences of testing were far more frequently reported than negative consequences (98% vs. 2%, respectively). Negative life events included banishment from the worksite (one case) and verbal abuse (two cases).

CONCLUSION

Acceptability of VCT appears high in the FSW population in Conakry as a consequence of both perceptions of high individual risk and social pressures.

Linking HIV prevention and care for community interventions among high-risk women in Burkina Faso--the ARNS 1222 "Yerelon" cohort

BACKGROUND

Interventions targeting core groups such as high-risk women in Africa have focused mostly on HIV prevention. In this marginalized group, the delegation of HIV care to public services may jeopardize the effectiveness of prevention activities. We assessed the effect of an intervention combining prevention and care among high-risk women on HIV exposure and treatment outcomes.

METHODS

In Burkina Faso, high-risk women were recruited by peer educators in an open-cohort study with 4-monthly follow-up visits. Primary prevention included peer-led information, education and communication sessions, condom distribution, regular HIV counselling and testing, and sexually transmitted infections management. Participants were offered free medical care including antiretroviral therapy (ART) and treatment adherence support by psychologists.

RESULTS

From December 2003, 658 high-risk women were enrolled and followed up for a median 20.8 months. Seven of the 489 HIV-uninfected women seroconverted (HIV incidence 0.9 of 100 person-years, 95% confidence interval: 0.24 to 1.58). HIV incidence tended to be higher during the first 8 months of follow-up than thereafter (1.43 vs. 0.39 per 100 person-years). Among 47 of 169 HIV-seropositive women who started ART, 79.4% achieved undetectable plasma viral load 6 months after initiation and 81.8% at 36 months. Condom use at last sexual intercourse with clients increased from 81.7% at enrollment to 98.2% at 12 months (P < 0.001) and from 67.2% to 95.9% (P < 0.001) with regular clients.

CONCLUSIONS

The integration of HIV care services, including the provision and support of ART, with a peer-led primary prevention package is pivotal to reduce HIV incidence and is likely to modify the local HIV dynamics.