Social networks of men who have sex with men and their implications for HIV/STI interventions: results from a cross-sectional study using respondent-driven sampling in a large and a small city in Tanzania.

Men who have sex with men (MSM) in sub-Saharan Africa remain hidden and hard to reach for involvement in HIV and sexually transmitted infection (STI) services. The aim of the current study was to describe MSM social networks in a large and a small Tanzanian city in order to explore their utility for peer-based healthcare interventions. Data were collected through respondent-driven sampling (RDS) in Dar es Salaam (n=197) and in Tanga (n=99) in 2012 and 2013, using 5 and 4 seeds, respectively. All results were adjusted for RDS sampling design. Mean personal network size based on the number of MSM who were reported by the participants, as known to them was 12.0±15.5 in Dar es Salaam and 7.6±8.1 in Tanga. Mean actual RDS network size was 39.4±31.4 in Dar es Salaam and 25.3±9.7 in Tanga. A majority (97%) reported that the person from whom they received the recruitment coupon was a sexual partner, close friend or acquaintance. Homophile in recruitment patterns (selective affiliation) was present for age, gay openness, and HIV status in Dar es Salaam, and for sexual identification in Tanga. The personal network sizes and existence of contacts between recruiter and referral indicate that it is possible to use peer-driven interventions to reach MSM for HIV/STI interventions in larger and smaller sub-Saharan African cities. The study was reviewed and approved by the University of Texas Health Science Center's Institutional Review Board (HSC-SPH-10-0033) and the Tanzanian National Institute for Medical Research (NIMR/HQ/R.8a/Vol. IX/1088).

Ross MW ，Larsson M ，Jacobson J ，Nyoni J ，Agardh A ... -  《BMJ Open》

High HIV seroprevalence, rectal STIs and risky sexual behaviour in men who have sex with men in Dar es Salaam and Tanga, Tanzania.

To assess HIV and sexually transmitted infection (STI) prevalence and associated risk factors in men who have sex with men (MSM) in two cities in mainland Tanzania. We conducted respondent-driven sampling of 300 MSM in Dar es Salaam and Tanga. In Dar es Salaam, 172 (86%) men (median age 23, IQR 21-28) consented to HIV/STI testing, and 30.2% were HIV seropositive. Only five reported a previous positive HIV test: >90% were new HIV detections. 2.5% were syphilis-exposed and none hepatitis B positive, but 21.4% had a curable STI. Over 90% of the gonorrhoea and chlamydia was rectal. In Tanga, 11.1% of MSM were HIV seropositive, 8% hepatitis B positive and 0% were syphilis-exposed, with 4.4% having a curable STI. Predictors of HIV infection were number of MSM known, city, identifying as gay and having first sex with a man. Predictors for STIs were recent unprotected receptive anal intercourse, and number of MSM seen in the last month. 30% of the sample reported that they sold sex. There was no significant association between HIV and STI infection. HIV and STI rates were substantially lower in MSM in a provincial city than in a large metropolis and rates appear to depend on larger numbers of MSM known. Most HIV detected were new cases, and there was a high burden of asymptomatic curable rectal STIs (>1 in 5 MSM). Owing to stigma, MSM may not report homosexuality and thus not have rectal STIs treated. High need for tailored HIV testing and STI screening and treatment of MSM in Tanzania is apparent.

Ross MW ，Nyoni J ，Ahaneku HO ，Mbwambo J ，McClelland RS ，McCurdy SA ... -  《BMJ Open》

HIV prevalence among men who have sex with men following the implementation of the HIV preventive guideline in Tanzania: respondent-driven sampling survey.

To estimate HIV prevalence and associated risk factors among men who have sex with men (MSM) in Dar es Salaam, Tanzania following the implementation of the national comprehensive package of HIV interventions for key population (CHIP). A cross-sectional survey using respondent-driven sampling. Dar es Salaam, Tanzania's largest city. Men who occasionally or regularly have sex with another man, aged 18 years and above and living in Dar es Salaam city at least 6 months preceding the study. HIV prevalence was the primary outcome. Independent risk factors for HIV infection were examined using weighted logistics regression modelling. A total of 777 MSM with a mean age of 26 years took part in the study. The weighted HIV prevalence was 8.3% (95% CI: 6.3%-10.9%) as compared with 22.3% (95% CI: 18.7%-26.4%) observed in a similar survey in 2014. Half of the participants had had sex with more than two partners in the month preceding the survey. Among those who had engaged in transactional sex, 80% had used a condom during last anal sex with a paying partner. Participants aged 25 and above had four times higher odds of being infected than those aged 15-19 years. HIV infection was associated with multiple sexual partnerships (adjusted OR/AOR, 3.0; 95% CI: 1.8-12.0), not having used condom during last sex with non-paying partner (AOR, 4.1; 95% CI: 1.4-7.8) and ever having engaged in group sex (AOR, 3.4; 95% CI: 1.7-3.6). HIV prevalence among MSM in Dar es Salaam has decreased by more than a half over the past 5 years, coinciding with implementation of the CHIP. It is nonetheless two times as high as that of men in the general population. To achieve the 2030 goal, behavioural change interventions and roll out of new intervention measures such as pre-exposure prophylaxis are urgently needed.

Alexander Ishungisa M ，Moen K ，Leyna G ，Makyao N ，Ramadhan A ，Lange T ，Meyrowitsch DW ，Mizinduko M ，Likindikoki S ，Leshabari M ，Mmbaga EJ ... -  《BMJ Open》

Lubricant use and condom use during anal sex in men who have sex with men in Tanzania.

The lack of data on condom and lubricant use among African men who have sex with men (MSM) hinders prevention efforts. We describe use, knowledge, and access to lubricants in Dar es Salaam and Tanga, Tanzania. Data were collected in 2012 and 2013 from a cross-sectional survey of 200 MSM in Dar es Salaam and 100 MSM in Tanga, Tanzania. The most common reason for not using condoms was dislike of condoms. Two-thirds of the men reported always using a lubricant for anal sex. Results showed that: fewer men who have sex with both men and women (MSMW) know about lubricants; more MSM look for, have difficulty finding, and find lubricants to be expensive; and MSM use lubricants to facilitate penetration. MSMW commonly receive their lubricants from their sexual partner, while MSM got them from friends and pharmacies. HIV-negative MSM used lubricants to facilitate penetration and reduce pain. HIV-positive MSM are likely to get their lubricants from pharmacies or friends. MSMW use Vaseline® significantly more than MSM as a lubricant. Results suggest that HIV prevention knowledge among MSM is greater, so HIV prevention efforts should emphasise carrying water-based lubricant among MSMW. Consequently, there is an opportunity to co-market condoms and water-based lubricants.

Romijnders KA ，Nyoni JE ，Ross MW ，McCurdy SA ，Mbwambo J ，Kok G ，Crutzen R ... -  《-》

Prevalence of STI symptoms and high levels of stigma in STI healthcare among men who have sex with men in Dar es Salaam, Tanzania: a respondent-driven sampling study.

Ross MW ，Larsson M ，Nyoni JE ，Agardh A ... -  《-》