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

Exploratory analysis of the potential impact of violence on HIV among female sex workers in Mombasa, Kenya: a mathematical modelling study

BACKGROUND

Understanding the frequency of violence experienced by female sex workers (FSWs) and how violence contributes to HIV transmission can help improve HIV programs.

METHODS

Using recent recommendations for modelling structural factors and associated causal pathways, we developed a HIV transmission dynamic model for FSWs and their clients in Mombasa, Kenya, mechanistically representing three types of violence (sexual violence, SV; physical violence, PV; police assault and arrest, PAA). Each type of violence affects HIV transmission through key mediators (condom non-use, HIV testing). We parameterized the model using data from a cross-sectional study of FSWs aged 15-24 recruited from a systematic geographical mapping sampling frame in Mombasa, Kenya (Cheuk E et al., Frontiers in Reproductive Health 2(7), 2020). Using this model, calibrated (and cross-validated) to HIV epidemiological and violence outcomes, we estimated the incidence of violence episodes, the contribution of violence to the HIV epidemic measured by the transmission population-attributable fraction, and the potential impact of possible violence interventions.

RESULTS

The median estimated incidence of PAA in 2023 among FSWs who had not previously experienced that type of violence was 0.20 (95% credible interval: 0.17-0.22) per person-year (ppy), about double the incidence of SV and PV (0.10 (0.09-0.11), 0.11 (0.09-0.12), respectively). The incidence of violence was higher among FSWs who had previously experienced violence: the incidence of recurrent PV was 2.65 (1.82-3.37) ppy, while the incidence of recurrent SV and PAA were 1.26 (0.80-1.67) and 1.37 (0.94-1.74 ppy, respectively. In this setting, we estimated that a median of 35.3% (3.4-55.8%) infections in FSWs and clients combined over the next 10 years may be due to all types of violence (and mediators), mainly through reduced condom use in FSWs who have ever experienced SV (34.6% (2.4-55.5%)). Interventions that prevent future violence without mitigating the effects of past violence may only prevent 8.8% (0.8-14.0%) infections over 10 years.

CONCLUSIONS

FSWs in Mombasa experience violence frequently. In this population, we find that addressing sexual violence, including mitigating the effects of past violence, is potentially important in reducing HIV transmission in this population. However, the wide uncertainty range shows longitudinal studies are needed to strengthen the evidence of the influence of violence on HIV risk behavior. We find that the recommendations for modelling structural factors provide a useful framework for describing the model.

Costs and cost drivers of comprehensive sexual reproductive health services to female sex workers in Kenya

BACKGROUND

Comprehensive sexual reproductive health (SRH) programs for female sex workers (FSW) offering clinical, behavioural, and structural interventions have contributed to declining rates of HIV in this population. However, data on costs and cost drivers is needed to support programs and their donors to better allocate resources, make an investment case for continued funding, and to identify areas of improvement in program design and implementation. We aimed to estimate the annual per-FSW costs of comprehensive services for a standalone FSW program in Kenya.

METHODS

We implemented a top-bottom and activity-based costing study of comprehensive FSW services at two drop-in centres (DICs), Mtwapa and Kilifi town, in Kilifi County, Kenya. Service costs were obtained from routinely collected patient data during FSW scheduled and unscheduled visits using Kenyan Ministry of Health records. Costing data were from the program and organization's expenditure reports, cross checked against bank documents and supported by information from in-depth interviews. Data were collected retrospectively for the fiscal year 2019. We obtained approval from the AMREF Research Ethics Committee (AMREF-ESRC P862/2020).

RESULTS

In 2019, the unit cost of comprehensive services was 105.93 USD per FSW per year, roughly equivalent to 10,593 Kenya shillings. Costs were higher at Mtwapa DICs compared to Kilifi town DIC; 121.90 USD and 89.90 USD respectively. HIV counselling and testing cost 63.90 USD per person, PrEP was 34.20 USD and family planning was 9.93 USD. Of the total costs, staff salaries accounted for about 60%. Adjusted for inflation, costs in 2024 would be approximately 146.60.

CONCLUSION

Programs should strive to maximize the number of FSW served to benefit from economies of scale. Given that personnel costs contribute most to the unit costs, programs should consider alternative designs which reduce personnel and other costs.

High prevalence of hepatitis B and HIV among women survivors of sexual violence in South Kivu province, eastern Democratic Republic of Congo

INTRODUCTION

Limited data are available on the prevalence rates of hepatitis B and acquired immunodeficiency syndrome (AIDS) among women survivors of sexual violence (WSSV) in South Kivu province, in the eastern part of the Democratic Republic of Congo (DRC), where armed conflicts persist. Here, we aimed to assess the prevalence of these two infections in this vulnerable local population.

METHODS

A total of 1002 WSSV, aged from 18 to 70 years old were enrolled from May 2018 to May 2020 at three healthcare facilities (Panzi, Mulamba and Bulenga hospitals), which are called "The One-Stop Centre Care Model" for the management of sexual violence in South Kivu. Blood samples were collected and tested for hepatitis B virus (HBV) and human immunodeficiency virus (HIV) antigens and antibodies using enzyme-linked immunoassay (ELISA) methods. Subsequently, viral load quantification for HBV and HIV were performed using the GeneXpert. Univariate and multivariate logistic regression models were used to assess factors associated with HIV-positive and HBV-positive status.

RESULTS

For HBV, overall prevalence was 8.9% (95% CI; 7.2-10.8%), 32.1% (95% CI; 29.3-35.0%), and 14.5% (95% CI; 12.3-16.8%) for HBsAg, anti-HBc and anti-HBs antibodies, respectively. Among the 89 HBsAg-positive patients, 17 (19.1%) were HBeAg-positive. The median age of individuals with a positive HBsAg test was higher than those with a negative test (median: 40 years (IQR 30-52) compared to 36 years (IQR 24-48)). Risk factors for HBV infection were age (≥35 years) (AOR = 1.83 [1.02-3.32]; p = 0.041), having no schooling (AOR = 4.14 [1.35-12.62]; p = 0.012) or only primary school-level (AOR = 4.88 [1.61-14.75]; p = 0.005), and multiple aggressors (AOR = 1.76 [1.09-2.84], p = 0.019). The prevalence of HIV was 4.3% [95% CI: 3.1-5.7%]. HIV/HBV co-infection occurred only in 5 individuals (0.5%). The HBV viral load was detectable (> 1 log10 UI/mL) in 61.8% of HBsAg-positive subjects and 64.8% HIV-positive subjects had a high viral load (≥ 3 log10 copies/mL).

CONCLUSION

This study revealed a high prevalence of HBV and HIV infections among WSSV in South Kivu. The results generated highlight the urgent need for systematic screening of HBV and HIV by integrating fourth-generation ELISA tests in HIV and HBV control programs.

Sexual practices, their influencers, and utilization of HIV services among female sex workers in Mombasa County, Kenya

Introduction

female sex workers (FSWs) are vulnerable to acquiring HIV and other sexually transmitted infections due to unprotected sex. Understanding and addressing the gaps in safer sex among FSWs can help to reduce HIV acquisition and transmission. This study described sexual practices, their correlates and use of HIV services among FSWs in Mombasa County, Kenya.

Methods

participants were recruited for a baseline survey by a time-location cluster randomized design at predetermined intervals from five bars and five clubs in Mombasa County until a sample size of 160 was reached. Descriptive statistics and inferential analysis using R were conducted, and p<0.05 was regarded as statistically significant.

Results

nearly all (99%) of the participants were unmarried, and 11% had tertiary education. Ninety-eight percent (98%) reported vaginal intercourse, 51% reported using alcohol/drugs before sex, and 28% practiced unprotected intercourse. About 64% had tested for HIV within three months, 14% believed that it is safe to reuse condoms, and 10% that it is safe to engage in unprotected sex. In bi-variate analysis, FSWs were more likely to engage in unprotected intercourse if they reported more frequent sex, more frequent sex with regular clients, poor HIV knowledge, alcohol/drug use, and violence. In multivariate analysis, risky sexual practices were associated with frequency of sexual intercourse, alcohol/drug use, and poor HIV knowledge.

Conclusion

female sex workers engage in unprotected sex while under the influence of substances, belief in re-using condoms and have high frequency of sexual intercourse. Inadequate knowledge of HIV and substance use significantly correlated with unprotected sex. Interventions to address these modifiable factors are needed to mitigate the risk of HIV among FSWs.

The epidemiology of HIV infection among female sex workers in Nairobi, Kenya: A structural determinants and life-course perspective

High HIV prevalence among female sex workers (FSWs) is heavily influenced by structural determinants (e.g. criminalisation of sex work; violence) and significant life events (e.g. orphanhood, teenage pregnancy). This study aims to understand the epidemiology of HIV among FSWs in Nairobi, Kenya using a structural determinants and life-course perspective. Baseline cross-sectional survey data were collected June-December 2019 for the Maisha Fiti study with 1003 FSWs (aged 18-45 years). Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression with a hierarchical modelling approach. HIV prevalence was 28.0%, and increased with age (<25 years 5.7%, 25-34 years 19.0%, ≥35 years 40.6%). In adjusted analyses, HIV seroprevalence was associated with childhood and adolescence including violence from militia or soldiers (AOR = 1.60; 95%CI:1.00-2.53), young age at sexual debut (≤15 years old vs. ≥18 years AOR = 0.57; 95%CI:0.39-0.84) and teenage pregnancy (AOR = 1.37; 95%CI:1.00-1.88). For adulthood the factors included lower SES score (lowest vs. highest tertile AOR = 0.63; 95%CI:0.40-0.98); reduced housing insecurity (AOR = 0.52; 95%CI:0.54-0.79); lower alcohol/drug use score (AOR = 0.44; 95%CI:0.31-0.61); and a longer duration of selling sex (0-5 years vs. ≥11 years AOR = 2.35; 95%CI:1.44-3.82). Among HIV-negative FSWs, prevalence of HIV risk factors was high (recent hunger 32.3%; internalised 67.7% and experienced 66.0% sex work stigma; recent police arrest 30.1%; recent physical or sexual violence 65.6%, condomless last sex intimate partner 71.1%; harmful alcohol or substance use 49.1%). Only 24.6% of HIV-negative FSWs reported taking PrEP. Taken together, adverse events in childhood and adolescence were associated with increased odds of living with HIV, and were more strongly associated with HIV serostatus than adulthood structural or behavioural risk factors. HIV-negative FSWs remain at high risk of HIV acquisition. This study highlights the importance of addressing adverse events throughout the life course to reduce HIV risk, and the need to continue multi-level HIV prevention and treatment efforts.

Assessment of the lifetime prevalence and incidence of induced abortion and correlates among female sex workers in Mombasa, Kenya: a secondary cohort analysis

INTRODUCTION

Prevalence of lifetime-induced abortion in female sex workers (FSWs) in Kenya was previously estimated between 43% and 86%. Our analysis aimed at assessing lifetime prevalence and correlates, and incidence and predictors of induced abortions among FSWs in Kenya.

METHODS

This is a secondary prospective cohort analysis using data collected as part of the WHISPER or SHOUT cluster-randomised trial in Mombasa, assessing effectiveness of an SMS-intervention to reduce incidence of unintended pregnancy. Eligible participants were current FSWs, 16-34 years and not pregnant or planning pregnancy. Baseline data on self-reported lifetime abortion, correlates and predictors were collected between September 2016 and May 2017. Abortion incidence was measured at 6-month and 12-month follow-up. A multivariable logistic regression model was used to assess correlates of lifetime abortion and discrete-time survival analysis was used to assess predictors of abortions during follow-up.

RESULTS

Among 866 eligible participants, lifetime abortion prevalence was 11.9%, while lifetime unintended pregnancy prevalence was 51.2%. Correlates of lifetime abortions were currently not using a highly effective contraceptive (adjusted OR (AOR)=1.76 (95% CI=1.11 to 2.79), p=0.017) and having ever-experienced intimate partner violence (IPV) (AOR=2.61 (95% CI=1.35 to 5.06), p=0.005). Incidence of unintended pregnancy and induced abortion were 15.5 and 3.9 per 100 women-years, respectively. No statistically significant associations were found between hazard of abortion and age, sex work duration, partner status, contraceptive use and IPV experience.

CONCLUSION

Although experience of unintended pregnancy remains high, lifetime prevalence of abortion may have decreased among FSW in Kenya. Addressing IPV could further decrease induced abortions in this population.

TRIAL REGISTRATION NUMBER

ACTRN12616000852459.

Unmet Need for Contraception Among Female Sex Workers Initiating Oral Pre-Exposure Prophylaxis for HIV Prevention During Kenya's National Scale-Up: Results From a Programmatic Surveillance Study

Background

Female sex workers (FSWs) experience a higher risk for both HIV acquisition and unwanted pregnancies compared to women in the general population. Pre-exposure prophylaxis (PrEP) for HIV prevention offers protection against HIV infection but has no contraceptive effect. We examined the determinants of unmet need for contraception among FSWs who initiated PrEP to inform programs and policies to optimize contraceptive services and avert unwanted pregnancy among this high-risk group.

Materials and Methods

A cross-sectional analysis was conducted on routine, de-identified client data from a large-scale PrEP service delivery project, from February 2017 to December 2019. Data were collected from FSWs during clinic visits using Ministry of Health approved tools. Records for all 17,456 FSWs initiated on PrEP from 79 health facilities in 10 counties across three geographic clusters with high and medium HIV incidence were examined for eligibility for the analysis. Unmet need for non-barrier contraception was defined as not being pregnant, not currently using the non-barrier contraceptive method, and not trying to conceive or intending to have a child in the near future. Univariate and multivariable regression analyses were conducted with selected variables to examine associations.

Results

In the 79 sites, eligible records from 17,063 FSWs who initiated PrEP were included. Two-thirds were under 30 years, and the majority were not married and had received PrEP at drop-in centers. Overall, the unmet need for non-barrier contraception was 52.6%, higher for those under 20 years of age (60.9%) and those served in public and private health facilities (67.4 and 83.2%, respectively) rather than drop-in centers (50.6%). Women from the Nairobi and Coast cluster regions reported a higher unmet need for contraception compared to those from the Lake region. All these associations were significant (p < 0.05) at the multivariate level.

Conclusions

The high unmet need for non-barrier contraception among FSWs initiating PrEP highlights the need for integrated delivery of contraception services within PrEP programs. Identifying groups with a high unmet need could lead to higher success in an integrated program. Two recommended approaches include training healthcare providers to deliver clear contraception messaging during PrEP initiation and making a range of contraceptives accessible within PrEP services for high-risk groups. Furthermore, accelerated research on multipurpose prevention technologies is necessary to reduce the burden on individuals using multiple prevention products concurrently.

A decade and beyond: learnings from HIV programming with underserved and marginalized key populations in Kenya

INTRODUCTION

Key populations (KP) continue to account for high HIV incidence globally. Still, prioritization of KP in the national HIV prevention response remains insufficient, leading to their suboptimal access to HIV programmes. This commentary aims to share Kenya's challenges and successes in achieving 2020 global HIV targets and scaling up the KP programme in the last decade.

DISCUSSION

The KP programme in Kenya has scaled up in the last decade with the inclusion of female sex workers (FSW), men who have sex with men (MSM), people who inject drugs (PWID), transgender people and people in prisons as priority populations in the national HIV response. KP coverage based on official size estimates for FSW is 73%, for MSM is 82%, for PWID through needle syringe programme (NSP) is 71%, and through opioid substitution therapy (OST) is 26% and for transgender people is 5%. The service outcomes for KP have been relatively strong in prevention with high condom use at last paid sex for FSW (92%) and use of sterile equipment among PWID (88%), though condom use at last sex with a non-regular partner among MSM (78%) is still low. The KP programme has not met care continuum targets for all subpopulations with low case findings. The national KP programme led by the Ministry of Health has scaled up the programme through (a) strategic partnerships with KP-led and competent organizations, researchers and donors; (b) development of policy guidance and programme standards; (c) continuous sensitization and advocacy to garner support; (d) development of national reporting systems, among others. However, the programme is still struggling with uncertain size estimates; lack of updated bio-behavioural survey data; inadequate scale-up of interventions among transgender people and people in prison settings; gaps in reaching adolescent and young KP, and effectively addressing structural barriers like violence and stigma.

CONCLUSIONS

To reach the ambitious global HIV targets, sufficient coverage of KP with quality HIV programmes is critical. Despite scaling up the KP programme, Kenya has not yet achieved the 2020 global HIV targets and needs more efforts to scale-up quality programmes for KP who are underserved in the HIV response.