Female sex workers (FSWs) in sub-Saharan Africa are at high risk for acquiring and transmitting HIV  and have been identified as a key population by the National AIDS Control Council in Kenya. Therefore, the Kenya AIDS Control Program (KACP) provides a focused HIV prevention program to FSWs in Nairobi, with services partly based on the ‘best practices’ recommended by the Joint United Nations Programme on HIV/AIDS (UNAIDS) . These services include community empowerment, condom promotion and provision, sexually transmitted infection (STI) screening and treatment, HIV postexposure prophylaxis (PEP), and antiretroviral therapy provision for women who acquire HIV.
PEP consists of the provision of oral combination antiretroviral therapy shortly after a known or possible HIV sexual exposure for a period of 4 weeks, and may reduce HIV acquisition risk by 10-fold or more [3,4][3,4]. In the context of sex work, PEP allows vulnerable women to reduce the risk of HIV acquisition after a possible sexual exposure for reasons that may have been out of their control, including condom breakage, inability to negotiate condom use, or sexual assault . However, potential barriers to PEP include cost, potential side-effects, and the need for timely access. Therefore, PEP provision is not standard practice in low and middle-income countries .
Although PEP has been offered free of charge to FSWs attending KACP clinics in Nairobi since 2009, a recent analysis demonstrated that only just over 10% of clinic participants had accessed this service . Therefore, we performed a program assessment among FSWs attending KACP clinics in order to elucidate knowledge of and potential barriers to PEP access.
Participants and survey administration
An anonymous questionnaire was administered to Nairobi FSWs attending KACP clinics during May–August 2013. All FSWs over the age of 18 were eligible. Participants were recruited on a convenience basis, and participation was voluntary. Participants were not offered incentives or compensation. The study was a quality improvement initiative for programs approved by the Institutional Review Boards at Kenyatta National Hospital (Kenya) and the Universities of Toronto and Manitoba (Canada). Surveys were administered in a one-on-one interview format in Kiswahili or in English, and responses were recorded by the staff administering the survey. HIV testing was performed according to Kenyan national guidelines, with initial screening by antibody-based rapid test Determine HIV 1/2 (Inverness Medical, Tokyo, Japan) and confirmation of positive tests using SD Bioline HIV 1/2 (Standard Diagnostics Inc., Kyonggi Do, South Korea).
A sexual act was considered high risk if it presented a reasonable possibility of HIV exposure, defined as condomless vaginal or anal sex with a new or regular client, or sexual assault. Condomless sex with a regular partner or boyfriend was considered high risk if his HIV status was unknown, or was known to be HIV positive. FSWs were categorized as HIV low risk or high risk, with the latter defined as the self-report of any high-risk sex act during the past year. Nonparametric analysis with the Mann–Whitney test was used to compare continuous variables between groups, and discrete variables were compared with the Pearson χ2 test; a P value of less than 0.05 was considered significant.
Participant recruitment and demographics
Questionnaires were completed by 250 clinic attendees; 153/250 (61.2%) participants were HIV uninfected by rapid HIV testing. Formal records were not kept regarding the number of potential participants who declined participation. HIV-uninfected FSWs had a median age of 29 years (range, 18–54 years), and had been in sex work for 5 years. Although the median income per day from sex work was 1500 KSH, this ranged widely from 150 to 10 500 KSH/day. Women reported a weekly median of five repeat clients and four new clients.
Among 153 HIV-uninfected respondents, 19 were excluded from analysis because of missing information on sexual behavior, which prevented calculation of number of high-risk sexual encounters. Of the remaining 134 FSWs, 64 (47.8%) were HIV high risk, defined as the self-report of any high-risk sex act during the past year (see in the previous paragraph), and 70 (52.2%) were categorized as HIV low risk.
Associations of postexposure prophylaxis knowledge and access
Among the 134 eligible HIV-uninfected participants, 65 (48.5%) reported knowledge of PEP, 42 (31.6%) had ever accessed PEP, and 23 (56.1%) of those accessing PEP had completed the regimen. There were no significant associations of PEP knowledge or use with age, education, duration of sex work, or other demographic variables (data not shown). However, the number of high-risk sexual events per year varied significantly between women who had or had not accessed PEP. Specifically, there were a significantly lower number of high-risk sexual acts over the past year among those who had accessed PEP compared with those who had not (median 0 vs. 26 high-risk sexual acts; P = 0.016). Interestingly, 109/153 HIV-uninfected FSW (71.2%) reported that they would be interested in taking an antiretroviral pill every day if it was able to protect them against HIV.
PEP knowledge and access was then compared between sex workers categorized as HIV high or low risk. The 70 FSWs categorized as HIV low risk were more likely to have heard of PEP than the 64 high-risk FSWs (58.6 vs. 37.5%, χ2(1) = 6.00, P = 0.014; Fig. 1) and were more likely to have accessed PEP than high-risk FSWs (40.6 vs. 21.9%, χ2(1) = 5.46, P = 0.019). When analysis was limited to the subset of women who had previously accessed PEP (n = 42), there was a trend toward low-risk FSWs being more likely to complete a full course of PEP than high-risk FSWs (66.7 vs. 35.7%; χ2(1) = 3.61, P = 0.058; Fig. 1, right columns).
HIV postexposure prophylaxis among high-risk female sex workers
There were 14 women who were categorized as being at high risk of HIV acquisition and who had accessed PEP. These women were significantly more likely to report having been treated for an STI or genital infection than the 50 non-PEP users (Table 1). Among high-risk women, PEP users were also significantly more likely than non-PEP users to report having had unprotected sex with a known or suspected HIV-infected man, any sex with a known HIV positive man in the last 6 months, and to have children (Table 1). Although the proportion drinking any alcohol was similar between groups, among high-risk FSWs who drank alcohol (n = 50), the number of drinks per week was twice as high among FSWs who had accessed PEP (Table 1).
Compared with the five high-risk women who reported perfect adherence, the nine high-risk women who did not complete the PEP course were more likely to report having sex without a condom with someone who is HIV infected (42.9 vs. 0.0%, χ2(1) = 3.94, P = 0.047) or having had HIV-infected sexual partners in the last 6 months (83.3 vs. 0.0%, χ2(1) = 5.18, P = 0.023), and had fewer children (median 1 vs. 3 children; Mann–Whitney P = 0.004). FSWs reporting PEP noncompletion were also more likely to report prior treatment for an STI or genital infection (88.9 vs. 40.0%, χ2(1) = 3.74, P = 0.053).
HIV PEP could be an important clinical tool to reduce HIV acquisition, and FSWs in sub-Saharan Africa are a key population at high HIV risk [1,2][1,2]. This survey, which was conducted among attendees at a dedicated FSW clinic that has been providing PEP since 2009, highlights several key issues regarding client understanding of, access to, and adherence with PEP. Although PEP was available at no cost to FSWs seeking care at Nairobi-based FSW clinics, lack of PEP knowledge remained a major barrier to access. Furthermore, nearly half of the FSWs accessing PEP did not complete the regimen. Ideally, FSWs, who engage in unprotected sex, would access PEP more often than FSWs who report perfect condom use. Therefore, our findings that a lack of PEP knowledge, reduced PEP access, and incomplete PEP adherence were all significantly more common among the FSWs at the highest risk of contracting HIV were of particular concern.
Given these findings, clinics that provide prevention and care services for FSWs should offer continuing educational sessions and targeted counseling around PEP for FSWs, with enhanced targeting of women who report high-risk sexual encounters such as condom breakage or sexual assault. Ongoing evaluation will then be needed to assess whether this translates into improved PEP uptake and adherence, and potentially to test novel strategies to enhance adherence.
Having children was a predictor of PEP use among high-risk women, and having more children was associated with improved PEP adherence. This is in keeping with findings from India, where the welfare and financial security of children were FSWs’ major concerns, and women were most likely to seek healthcare if illness caused an inability to provide . Increased alcohol intake has been associated with an increase in condomless sex among FSWs [8,9][8,9] and with increased HIV prevalence and incidence among Nairobi FSWs [10,11][10,11]. Therefore, it was encouraging that alcohol intake was associated with more PEP use among high-risk women.
Recent studies in men who have sex with men demonstrated that preexposure prophylaxis (PrEP) was more than 95% effective at preventing HIV acquisition if compliance was high . Although it is not yet clear whether the same efficacy will be seen for penile-vaginal sex , it is likely that antiretroviral-based PrEP will prove beneficial. Therefore, appropriate access to PEP services by an FSW may well serve as a key indicator for PrEP need, particularly if PEP is accessed more than once, as was seen in a subset of the Nairobi cohort . Therefore, it was encouraging that almost three-quarters of FSW surveyed indicated potential interest in taking an antiretroviral tablet daily to prevent HIV infection.
Although we believe that this study has important implications for HIV prevention in FSWs, some potential weaknesses merit discussion. Most importantly, questionnaires were only administered to FSWs attending KACP clinics, and data could only be assessed from FSWs who agreed to participate. It is therefore unknown to what extent the results apply to FSWs not in care, FSWs who accessed PEP or other prevention services but then did not return to the program, or FSWs who refused the questionnaire. Nonetheless, although it is likely that such women differ from participants in several important ways, our results have clear implications for quality improvement within our program, and merit broader consideration within FSW clinics elsewhere. Only HIV-uninfected women were considered in this analysis, although it may be useful for future studies to also quantify PEP knowledge among recently HIV-infected FSWs. The 250 women sampled for this quality improvement initiative represent approximately 5% of the entire FSW clinical outreach program , and approximately 20% of attendees at the study clinics during the period of recruitment.
In summary, within a well established network of clinics providing HIV care and prevention services to FSWs from Nairobi, those women at highest HIV risk were less likely to have heard of PEP, access PEP, or complete the full course of therapy once initiated. This should be seen as an opportunity to develop targeted strategies that will improve access and adherence to PEP (and later PrEP) among high-risk women who are most in need of effective HIV prevention.
Funding: A.V.O. and N.S. were supported by a Comprehensive Research Experience for Medical Students (CREMS) Award from the University of Toronto. R.K. was supported by a University of Toronto/OHTN Endowed Chair in HIV Research.
Conflicts of interest
There are no conflicts of interest.
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