Estimating the number of people who inject drugs, female sex workers, and men who have sex with men, Unguja Island, Zanzibar: results and synthesis of multiple methods.

To determine the number of people who inject drugs (PWID), female sex workers (FSW) and men who have sex with men (MSM) living in Unguja Island, Zanzibar in 2011/2012, we applied several, practical population size estimation methods including literature review, unique object multiplier, recapture from the 2007 survey, wisdom of the crowds and service multiplier. We synthesized findings and presented them to a panel of experts in order to determine plausible estimates for each population. The estimates adopted by a panel of experts as being most plausible were 3,000 for PWID, 3,958 for FSW and 2,157 for MSM. We learned that no one method could be concluded to be the standard for all three populations. The estimates we found, though still not perfect, are useful for the HIV programmes serving these populations.

Increased utilisation of PEPFAR-supported laboratory services by non-HIV patents in Tanzania.

BACKGROUND: It is unknown to what extent the non-HIV population utilises laboratories supported by the President's Emergency Plan for AIDS Relief (PEPFAR). OBJECTIVES: We aimed to describe the number and proportion of laboratory tests performed in 2009 and 2011 for patients referred from HIV and non-HIV services (NHSs) in a convenience sample collected from 127 laboratories supported by PEPFAR in Tanzania. We then compared changes in the proportions of tests performed for patients referred from NHSs in 2009 vs 2011. METHODS: Haematology, chemistry, tuberculosis and syphilis test data were collected from available laboratory registers. Referral sources, including HIV services, NHSs, or lack of a documented referral source, were recorded. A generalised linear mixed model reported the odds that a test was from a NHS. RESULTS: A total of 94 132 tests from 94 laboratories in 2009 and 157 343 tests from 101 laboratories in 2011 were recorded. Half of all tests lacked a documented referral source. Tests from NHSs constituted 42% (66 084) of all tests in 2011, compared with 31% (29 181) in 2009. A test in 2011 was twice as likely to have been referred from a NHS as in 2009 (adjusted odds ratio: 2.0 [95% confidence interval: 2.0-2.1]). CONCLUSION: Between 2009 and 2011, the number and proportion of tests from NHSs increased across all types of test. This finding may reflect increased documentation of NHS referrals or that the laboratory scale-up originally intended to service the HIV-positive population in Tanzania may be associated with a 'spillover effect' amongst the general population.

HIV risk and the overlap of injecting drug use and high-risk sexual behaviours among men who have sex with men in Zanzibar (Unguja), Tanzania.

BACKGROUND: Men who have sex with men and inject drugs (MSM-IDU) are particularly vulnerable to HIV infection and have the potential to transmit HIV across multiple populations through their male and female sexual partners and injection drug-using partners. METHODS: Respondent-driven sampling was used to recruit men who reported engaging in anal sex with another man in the past 3 months, aged ≥15 years, and living in Unguja, Zanzibar. Participants responded to a face-to-face interview about their HIV and injecting risk behaviours and were tested for HIV, Hepatitis B (HBV) and C (HCV) and syphilis. RESULTS: Among the 509 MSM who enrolled in the survey, 14% (n=66) reported injecting drugs in the past 3 months among which 66% used heroin, 60% used a needle after someone else had and 68% passed a needle to someone else after using it. MSM-IDU were significantly more likely to have two or more non-paying male receptive sex partners and to have engaged in group sex in the past month, to have symptoms of a sexually transmitted infection in past 6 months, to have been arrested or beaten in the past 12 months and to be infected with HIV and co-infected with HIV and HCV compared to MSM who did not inject drugs. MSM-IDU were less likely to have used a condom at last sex with a non-paid female partner, to know where to get a confidential HIV test and to have ever been tested for HIV compared to MSM who did not inject drugs. CONCLUSION: MSM-IDU, and MSM in general, in Unguja practice multiple high-risk behaviours that put them at risk for blood-borne and sexual transmission of HIV and HCV infection. Targeted interventions for MSM-IDU must account for the overlap of high-risk sexual and drug-using networks and integrate injection drug use and HIV services.