Risk factors for HIV and STI diagnosis in a community-based HIV/STI testing and counselling site for men having sex with men (MSM) in a large German city in 2011–2012

Abstract

Background: In recent years community-based voluntary counselling and testing sites (CB-VCT) for men having sex with men (MSM) have been established in larger cities in Germany to offer more opportunities for HIV testing. Increasingly, CB-VCTs also offer testing for other bacterial sexually transmitted infections. In Hamburg, tests in CB-VCTs are offered free and anonymously. Data on demographics and sexual risk behaviours are collected with a paper questionnaire. Methods: Questionnaire data from the MSM CB-VCT in Hamburg were linked with serological test results for HIV and syphilis, and with rectal and pharyngeal swab results for gonorrhoea and chlamydia. MSM were defined as males reporting male sex partners. CB-VCT clients were characterized demographically, and associations between sexual behaviour variables and diagnosis of HIV and sexually transmitted infections (STI) were analysed by bivariate and multivariate logistic regression analysis. Results: Among the male clients of the CB-VCT in 2011–2012 who were tested for HIV or any STI 1476 reported male sex partners. Unprotected anal intercourse (UAI) was reported as reason for testing by 61% of the clients. Forty-one of 1413 clients testing for HIV were tested positive (2.9%). Twenty-four of 1380 clients testing for syphilis required treatment (1.7%). Tests for simultaneous detection of N. gonorrhoea and Chlamydia trachomatis were conducted on 882 pharyngeal and 642 rectal swabs, revealing 58 (=6.6%) pharyngeal and 71 (=11.1%) rectal infections with one or both pathogens. In multivariate logistic regression analysis number of partners, UAI (OR=2.42) and relying on visual impression when selecting sex partners (OR = 2.92) were associated with increased risks for diagnosis of syphilis or a rectal STI. Syphilis or rectal STI diagnosis (OR=4.52) were associated with increased risk for HIV diagnosis. Conclusions: The MSM CB-VCT in Hamburg reaches clients at high risk for HIV and STIs. The diagnosis of syphilis or a rectal STI was associated with increased odds of testing positive for HIV. Due to the high prevalence of curable bacterial STI among clients and because syphilis and rectal bacterial STI may facilitate HIV transmission, MSM asking for HIV tests in CB-VCTs should also be offered tests for other bacterial STIs.