PG-6 What partner characteristics predicts condom use in a network of MSM in Nigeria?
Authors: Olawore Oluwasolape , Crowell Trevor , Omari S. , Liu Hongjie , Ketende Sosthenes , Charurat Man , Nowak Rebecca , Baral Stefan 
Published: April 2019

Even in the context of a generalized HIV epidemic in Nigeria, men who have sex with men (MSM) carry a disproportionate burden of HIV in the country with 18% reported to be living with HIV compared to 4% of the general population. In the context of emerging HIV prevention strategies including PrEP, consistent condom use (CCU) remains a mainstay of HIV prevention among MSM. The consistent use of condoms may however not only be influenced by individual level behavioural risk factor but also partner risk characteristics. Here we assess the prevalence of consistent condom use across time in a cohort of MSM as well as the partner characteristics and risk factors associated with CCU.

TRUST/RV368, as a prospective cohort study, evaluates the efficacy of peer-driven chain referral network-based recruitment of MSM into HIV testing, care, treatment, and prevention services at trusted community-based venues. The cohort enrolls MSM and TGW participants in Abuja and Lagos, Nigeria, using respondent-driven sampling (RDS). Participants who were recruited into the study between March 2013 and March 2018, who reported having anal sex and who had information about at least one sexual partner were included in these analyses. Participants were classified as consistently using condoms if they reported always using condoms all the times they had insertive or receptive anal sex or both types of sex with a male partner. Participants (egos) were then asked questions about the demographics and risk behaviors of up to 5 of their sexual partners (alters) at alternating visits. Crude and multivariable mixed effect Poisson regression models with clustering on the ego and 95% confidence intervals were used to assess the characteristics of the alters associated with the ego's condom use. The multivariable model was adjusted for time, site and how true the egos believed the responses they provided about the alters were.

1474 participants (egos) reported on 9654 most recent sexual partners (alters). The median age of egos was 24 years (1QR: 21–27) while the median age of the alters was 26 (IQR: 23–30). Most of the egos identified as men (79%) while 32% of them were homosexual or gays. Alters tended to be older than the egos (61%), of a higher socio-economic status than the egos (56%), more educated than the egos. Although inconsistent condom use was common in the cohort, there was a trend of increasing consistent usage of condoms across study visits (visit 1: 41%, visit 2: 67%, visit 3: 75%). In the crude analysis, the partner characteristics associated with ego CCU included, a more educated alter, alters consistently using a condom with other sexual partners and the alter encouraging the ego to use condoms with partners. In the multivariable analysis, factors associated with CCU were a more educated alter, alter consistently using a condom with other partners and alter having the same socio-economic status as the ego. Egos who reported that their sexual partners ever had an STI symptom (RR: 0.93; 95% CI: 0.87 to 0.99), ever paid money to have sex were less likely to consistently use condoms (RR: 0.93; 95% CI: 0.87 to 0.98). Egos who never or rarely discussed HIV with alters also had a reduced risk of CCU (Never—RR: 0.83; 95% CI: 0.77 to 0.90, Rarely—RR: 0.89; 95% CI: 0.82 to 0.96) as well as a sexual partner being older (RR: 0.92; 95% CI: 0.89 to 0.97).

Although consistent condom use was observed in this cohort of MSM, condomless sex was still common. High risk behaviors among sexual partners of MSM is associated with a reduced likelihood of CCU. The data presented here highlights the need for new approaches including structural interventions targeted to partners of MSM who may not be engaged in care. Furthermore, approaches that safely increase condom use such as provision of condoms in safe spaces, education on proper usage of condoms as well as better condoms and lubricants are needed to prevent the acquisition and transmission of HIV.