Baseline findings of an HIV incidence cohort study to prepare for future HIV prevention clinical trials in Kisumu, Kenya

Feasibility of conducting HIV prevention trials among key populations in Nairobi, Kenya

OBJECTIVE

To assess the feasibility of conducting HIV prevention trials among key populations in Nairobi, Kenya.

BACKGROUND

HIV prevention trials require the inclusion of those at high risk of HIV infection and their informed decision to take part and remain in the clinical trial to the end is crucial. In Kenya key populations including men who have sex with men (MSM) and female sex workers (FSW) are, disproportionately, at high risk of HIV infection when compared to the general population. Few trials testing biomedical prevention products against HIV have enrolled Kenyan FSW and MSM.

METHODS

We performed simulated vaccine efficacy trial (SiVET) using licensed hepatitis B vaccines as substitutes for a HIV vaccine candidate and included randomization for those immune to hep B. The SiVET was an observational study designed to mimic the rigors of a clinical trial; we assessed HIV risk, provided risk counselling and prevention tools and performed HIV testing at baseline and periodically until the end of the trial. MSM and FSW were enrolled at a ratio of 4:1. Volunteers were assigned to either hepatitis B vaccine or placebo.

RESULTS

Recruitment took approximately 24 months between Sep 2015 and Sep 2017. Of the 368 volunteers screened, 250 (200 MSM and 50 FSW) were enrolled. Reasons for exclusion at screening included: being positive for HIV (n = 7), hepatitis (n = 14), other pre-existing medical conditions (n = 41), eligible but chose not to enrol (n = 47). Most of the volunteers adhered to study procedures and attended their study visits within the study window. These include volunteers who received the second vaccination 244 (98%), the third vaccination 228 (91%) and, the final study visit 217 (87%). The reasons volunteers discontinued from the study early included: relocation and loss to follow up (n = 14). A total of 8 cases of HIV infection were observed in 174.5 Person Years at Risk (PYAR), all among MSM, including 5 seroconversions identified at the last study visit, for a HIV incidence of 4.58 cases/ 100 PYAR, among MSM enrolled in the study.

CONCLUSION

Our findings suggest that it is possible to conduct HIV prevention trials among key populations in Nairobi with a good adherence to a vaccine efficacy trial schedule. Despite HIV prevention efforts, we also noted a high incidence of HIV infection. This demonstrates the need for effective HIV prevention products in these populations.

Oral sex practices among men who have sex with men and transgender women at risk for and living with HIV in Nigeria

Background

Men who have sex with men (MSM) and transgender women (TGW) are at risk for sexually transmitted infections (STIs), including those of the oropharynx. We estimated the prevalence and factors associated with oral sex practices and characterized oropharyngeal STIs among a cohort of MSM and TGW in Nigeria.

Methods

From 2013 to 2018, TRUST/RV368 recruited MSM and TGW into HIV/STI diagnosis and treatment at community-based clinics in Nigeria. Participants who completed HIV testing and oral sex questions at enrollment were selected. Cross-sectional analyses with bivariate and multivariable logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs). Oropharyngeal swab testing for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) began in 2014 and for those with diagnostic results at enrollment, the unadjusted association of oral sex practices with oropharyngeal STIs was conducted.

Results

A total of 1342 participants had a median age of 25 years (interquartile range: 22–29), 58% were living with HIV, and 69% reported oral sex practices. Factors associated with increased odds of engaging in oral sex included living with HIV (adjusted [a]OR: 1.4, 95% CI: 1.1–1.8), self-identifying as a woman (aOR:1.8, 95% CI: 1.1–2.8), mobile phone ownership (aOR:2.3, 95% CI: 1.3–3.9), receptive anal sex (aOR:1.7, 95% CI:1.3–2.3) and multiple male sexual partners (2 to 4 vs. ≤1, aOR:1.5, 95% CI: 1.0–2.2; 5+ vs ≤1, aOR:2.9, 95% CI:1.9–4.3). Oropharyngeal STI prevalence was 7% (52/752) and higher among those who engaged in oral sex compared to those who did not (unadjusted OR: 2.5, 95% CI:1.2–5.3).

Conclusions

Oral sex was common and associated with an increased odds of oropharyngeal STIs among MSM and TGW from Nigeria. In the absence of screening and treatment guidelines, condoms continue to be the mainstay for oral STI prevention. A pre-exposure prophylaxis for bacterial STIs would complement current prevention strategies to curb transmission.

Reported oral and anal sex among adolescents and adults reporting heterosexual sex in sub-Saharan Africa: a systematic review

BACKGROUND

Oral and anal sexual behaviours are increasingly reported among adolescents and adults reporting heterosexual sex in peer-reviewed journals in high income countries, but less is known about these behaviours in low and middle-income countries, especially in sub-Saharan Africa. The aim of this systematic review is to describe the prevalence of, and motivations for, oral and anal sex among adolescents and adults reporting heterosexual sex in sub-Saharan Africa.

METHODS

A systematic review of published articles that reported oral and or anal sex in sub-Saharan Africa was conducted from seven databases up to and including 30th August 2018.

RESULTS

Of 13,592 articles, 103 met the inclusion criteria. The prevalence of reporting ever practising oral sex among adolescents, university students and a combined population of adolescents/adults ranged from 1.7-26.6%, 5.0-46.4% and 3.0-47.2% respectively. Similarly, prevalences of reported ever practising anal sex ranged from 6.4-12.4% among adolescents, 0.3-46.5% among university students and 4.3-37.8% amongst combined population of adolescents and adults. Higher prevalences of oral and anal sex were reported among populations at high-risk for sexually transmitted infections and HIV and university students and, in most studies, both behaviours were more commonly reported by males than females. Heterosexual oral and anal sexual acts were associated with some high-risk behaviours such as inconsistent condom use and multiple sexual partners.

CONCLUSION

Reported oral and anal sex between men and women are prevalent behaviours in sub-Saharan Africa. Health professionals and policy makers should be aware of these behaviours and their potential associated health risks.

Heterosexual oral and anal sex in Kinshasa (D.R.Congo): Data from OKAPI prospective cohort

BACKGROUND

Sexually transmitted infections can be spread through oral and anal heterosexual sex. There are few data on these practices in Sub-Saharan Africa. We analyzed the prevalence of heterosexual oral and anal sex among HIV Voluntary Counseling and Testing (VCT) attendees in Kinshasa and the associated sociodemographics, perceptions and behavioral factors.

METHODS

OKAPI (Observational Kinshasa AIDS Prevention Initiative) prospective cohort study. It evaluates the VCT impact on HIV-related knowledge and behaviors at 6 and 12-month follow-up. Since April 2016 until April 2018, 797 persons aged 15-59 years were HIV tested and replied to a baseline interview, including information about anal and oral sex. Descriptive, bi- and multivariate analyses were performed using baseline data.

RESULTS

Among 718 sexually active participants reporting heterosexual sex, 59% had had oral sex, 22% anal sex and 18% both practices. Among participants reporting "not" having had sex, 6% reported oral sex, 3% anal sex and 1% both. Oral sex was associated with a daily use of the Internet/mobile phone, perceiving low community HIV risk, reporting HIV-related behaviors (multiple partners, inconsistent condom use, anal, paid and forced sex) and having been pregnant. Being married-monogamous was inversely associated with oral sex. Anal sex was directly associated with having other risk sexual behaviors.

CONCLUSIONS

Oral and anal sex were common among people reporting heterosexual sex in Kinshasa. Perceiving a low community HIV risk and having other sexual risk behaviors are associated with these practices, which are commonly not considered as risky despite their strong association with HIV/STIs. They need to be considered when designing preventive strategies in Kinshasa.

Joint spatial modelling of disease risk using multiple sources: an application on HIV prevalence from antenatal sentinel and demographic and health surveys in Namibia

Background

In disease mapping field, researchers often encounter data from multiple sources. Such data are fraught with challenges such as lack of a representative sample, often incomplete and most of which may have measurement errors, and may be spatially and temporally misaligned. This paper presents a joint model in the effort to deal with the sampling bias and misalignment.

Methods

A joint (bivariate) spatial model was applied to estimate HIV prevalence using two sources: 2014 National HIV Sentinel survey (NHSS) among pregnant women aged 15–49 years attending antenatal care (ANC) and the 2013 Namibia Demographic and Health Surveys (NDHS).

Results

Findings revealed that health districts and constituencies in the northern part of Namibia were found to be highly associated with HIV infection. Also, the study showed that place of residence, gender, gravida, marital status, number of kids dead, wealth index, education, and condom use were significantly associated with HIV infection in Namibia.

Conclusion

This study had shown determinants of HIV infection in Namibia and had revealed areas at high risk through HIV prevalence mapping. Moreover, a joint modelling approach was used in order to deal with spatially misaligned data. Finally, it was shown that prediction of HIV prevalence using the NDHS data source can be enhanced by jointly modelling other HIV data such as NHSS data. These findings would help Namibia to tailor national intervention strategies for specific regions and groups of population.

Prevalence, incidence and correlates of HSV-2 infection in an HIV incidence adolescent and adult cohort study in western Kenya

Background

Herpes simplex virus type 2 (HSV-2) infections are associated with increased risk of HIV transmission. We determined HSV-2 prevalence, incidence and associated risk factors, incidence among persons with indeterminate results, and prevalence of HSV-2/HIV co-infection among young adults (18–34 years) and adolescents (16–17 years) enrolled in an HIV incidence cohort study in western Kenya.

Methods

Participants (n = 1106; 846 adults) were screened and those HIV-1 negative were enrolled and followed-up quarterly for one year. HSV-2 was assessed using the Kalon enzyme immunoassay. HSV-2 incidence was calculated separately among HSV-2 seronegative participants and those indeterminate at baseline. Logistic regression was used to estimate the odds of HSV-2 infection and Poisson regression was used to assess HSV-2 incidence and associated factors.

Results

Overall, HSV-2 prevalence was 26.6% [95% confidence interval (CI): 23.9–29.4] and was higher in adults (31.5% [95% CI: 28.3–34.9]) than adolescents (10.7% [95% CI: 7.1–15.3]). Factors associated with prevalent HSV-2 included female gender, increasing age, HIV infection, history of sexually transmitted infection, low level of education, multiple sexual partners, and being married, divorced, separated or widowed. Overall HSV-2 incidence was 4.0 per 100 person-years (/100PY) 95% CI: 2.7–6.1 and was higher in adults (4.5/100PY) and females (5.1/100PY). In multivariable analysis only marital status was associated with HSV-2 incidence. Among 45 participants with indeterminate HSV-2 results at baseline, 22 seroconverted, resulting in an incidence rate of 53.2 /100PY [95% CI: 35.1–80.9]. Inclusion of indeterminate results almost doubled the overall incidence rate to 7.8 /100 PY [95% CI: 5.9–10.5]. Prevalence of HIV/HSV-2 co-infection was higher in female adults than female adolescents (17.1 [95% CI: 13.6–21.0] versus 3.4 [95% CI: 1.1–7.8]).

Conclusion

The high incidence rate among persons with indeterminate results underscores the public health concerns for HSV-2 spread and underreporting of the HSV-2 burden. Careful consideration is needed when interpreting HSV-2 serology results in these settings.

Incidence of HIV and the prevalence of HIV, hepatitis B and syphilis among youths in Maputo, Mozambique: a cohort study

Background

Prevalence of HIV in Mozambique among individuals aged 15–49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25–29 years and 35–39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.

Methods

The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18–24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.

Results

The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: ±1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97–6.31), 12.2% (95% CI 10.5%–14.0%), and 0.36% (95% CI 0.15%–0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67–1.92). Retention rates were stable throughout the study being 85.1% at the last visit.

Conclusion

Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country.

Correlates of prevalent HIV infection among adults and adolescents in the Kisumu incidence cohort study, Kisumu, Kenya

We estimated HIV prevalence and identified correlates of HIV infection among 1106 men and women aged 16-34 years residing in Kisumu, Kenya. Demographic, sexual, and other behavioural data were collected using audio computer-assisted self-interview in conjunction with a medical examination, real-time parallel rapid HIV testing, and laboratory testing for pregnancy, gonorrhoea, chlamydia, syphilis, and herpes simplex virus type 2. Multivariate logistic regression was used to identify variables associated with prevalent HIV infection by gender. Overall HIV prevalence was 12.1%. HIV prevalence among women (17.1%) was approximately two-and-one-half times the prevalence among men (6.6%). Odds of HIV infection in men increased with age (aOR associated with one-year increase in age = 1.21, CI = 1.07-1.35) and were greater among those who were uncircumcised (aOR = 4.42, CI = 1.41-13.89) and those who had an herpes simplex virus type 2-positive (aOR = 3.13, CI = 1.12-8.73) test result. Odds of prevalent HIV infection among women also increased with age (aOR associated with one-year increase in age = 1.16, CI = 1.04-1.29). Women who tested herpes simplex virus type 2 positive had more than three times the odds (aOR = 3.85, CI = 1.38-10.46) of prevalent HIV infection compared with those who tested herpes simplex virus type 2 negative. Tailored sexual health interventions and programs may help mitigate HIV age and gender disparities.

Correlates of prevalent sexually transmitted infections among participants screened for an HIV incidence cohort study in Kisumu, Kenya

We determined the prevalence of four sexually transmitted infections and the demographic and behavioural correlates associated with having one or more sexually transmitted infections among participants in an HIV incidence cohort study in Kisumu, western Kenya. Participants were enrolled from a convenience sample and underwent aetiologic sexually transmitted infection investigation. Demographic and behavioural information were collected and basic clinical evaluation performed. Multiple regression analysis was done to determine variables associated with having one or more sexually transmitted infections. We screened 846, 18- to 34-year-olds. One-third had at least one sexually transmitted infection with specific prevalence being: syphilis, 1.6%; gonorrhoea, 2.4%; herpes simplex virus type-2, 29.1%; chlamydia, 2.8%; and HIV, 14.8%. Odds of having any sexually transmitted infection were higher among participants who were women, were aged 20-24 or 30-34 years compared to 18-19 years, had secondary or lower education compared to tertiary education, were divorced, widowed or separated compared to singles, reported having unprotected sex compared to those who did not, reported previous sexually transmitted infection treatment, and tested HIV-positive. Multiple strategies are needed to address the overall high prevalence of sexually transmitted infections as well as the gender disparity found in this Kenyan population. Structural interventions may be beneficial in addressing educational and socio-economic barriers, and increasing the uptake of health-promoting practices.

Evaluation of syndromic management of sexually transmitted infections within the Kisumu Incidence Cohort Study

While laboratory aetiological diagnosis is considered the gold standard for diagnosis and management of sexually transmitted infections (STIs), syndromic management has been presented as a simplified and affordable approach for STI management in limited resource settings. STI signs and symptoms were collected using staff-administered computer-assisted personal interview and audio computer-assisted self-interview. Participants underwent a medical examination and laboratory testing for common STIs. The performance of syndromic management was assessed on the agreement between interviewing methods as well as accurate diagnosis. We screened 846 participants, of whom 88 (10.4%) received syndromic STI diagnosis while 272 (32.2%) received an aetiological diagnosis. Agreement between syndromic and aetiological diagnoses was very poor (overall kappa = 0.09). The most prevalent STI was herpes simplex virus type 2 and the percentage of persons with any STI was higher among women (48.6%) than men (15.6%, p < 0.0001). Agreement between audio computer-assisted self-interview and computer-assisted personal interview interviewing methods for syndromic diagnosis of STIs ranged from poor to good. Our findings suggest that syndromic management of STIs is not a sufficient tool for STI diagnosis in this setting; development and improvement of STI diagnostic capabilities through laboratory confirmation is needed in resource-limited settings.

Investigation of HIV Incidence Rates in a High-Risk, High-Prevalence Kenyan Population: Potential Lessons for Intervention Trials and Programmatic Strategies

Cost-effective HIV prevention programs should target persons at high risk of HIV acquisition. We conducted an observational HIV incidence cohort study in Kisumu, Kenya, where HIV prevalence is triple that of the national rate. We used referral and venue-sampling approaches to enroll HIV-negative persons for a 12-month observational cohort, August 2010 to September 2011, collected data using computer-assisted interviews, and performed HIV testing quarterly. Among 1292 eligible persons, 648 (50%) were excluded for HIV positivity and other reasons. Of the 644 enrollees, 52% were women who were significantly older than men (P<.01). In all, 7 persons seroconverted (incidence rate [IR] per 100 person-years=1.11; 95% confidence interval [CI] 0.45-2.30), 6 were women; 5 (IR=3.14; 95% CI 1.02-7.34) of whom were ≤25 years. Most new infections occurred in young women, an observation consistent with other findings in sub-Saharan Africa that women aged ≤25 years are an important population for HIV intervention trials in Africa.