Is Group Sex a Higher-Risk Setting for HIV and Other Sexually Transmitted Infections Compared With Dyadic Sex Among Men Who Have Sex With Men?

BACKGROUND: Group sex has been suggested as a potential high-risk setting for HIV and other sexually transmitted infections (STIs) among men who have sex with men (MSM). We investigated whether group sex is associated with lower condom use during anal sex and higher proportions of STIs compared with dyadic sex among HIV-negative MSM between 2009 and 2012. METHODS: Cross-sectional data from 7 data waves of the Amsterdam Cohort Studies were used. The sample consisted of 465 MSM who either reported both group and dyadic sex (at n = 706 visits) or dyadic sex only (at n = 1339 visits) in the preceding 6 months. Logistic regression with generalized estimating equations was used to investigate the association between sexual setting (group vs. dyadic sex), condomless anal sex, and STI. RESULTS: Group sex was reported at 35% (706/2045) of visits. Condomless sex was more often reported during dyadic than group sex (odds ratio, 3.64 95% confidence interval, 2.57-5.16). Men who had group sex were more likely diagnosed as having gonorrhea compared with men with dyadic sex (odds ratio, 1.71; 95% confidence interval, 1.08-2.97), but this effect was not retained in the multivariate model. CONCLUSIONS: Results demonstrate within-person differences in sexual behavior during group and dyadic sex among MSM. Men were more likely to use condoms during group sex than during dyadic sex. Thus, for some, group sex may not necessarily be risky for HIV infection compared with dyadic sex. However, group sex may be a higher-risk setting for acquiring STIs other than HIV, such as gonorrhea. Group sex encounters should be recognized as distinct sexual settings with specific risk characteristics that need to be addressed accordingly.

Incidence of acute hepatitis B in different ethnic groups in a low-endemic country, 1992-2009: increased risk in second generation migrants.

BACKGROUND: The Netherlands is a low-incidence country for acute hepatitis B (HBV) infection (1.2/100,000 in 2010), where it is typically acquired in adulthood through injecting drug use or homosexual exposure. Recently, the number of heterosexually acquired acute infections in the Netherlands has increased. Ethnicity may be a risk factor. We describe trends in the incidence of acute HBV among heterosexual adults in ethnic groups in Amsterdam from 1992 to 2009 and discuss future control of HBV in the Netherlands. METHODS: We studied all cases of acute HBV acquired in heterosexuals aged ≥15 years in the Amsterdam region (1992-2009, n=238) by ethnic group. Incidence rates were estimated as the average number of cases per 100,000 per year. Using Poisson regression, we calculated univariable and multivariable incidence rate ratios (IRR) by ethnic group over calendar year, by age and gender. RESULTS: The incidence in first generation migrants from HBV-endemic countries (FGM) was 4.1/100,000 showing no trend over time. Since 1999, incidence in Dutch-born cases in Amsterdam has increased by 13% annually from 0.2/100,000 in 1999 to 2.1/100,000 in 2009 (annual IRR 1.13, 95% CI:1.0-1.22). From 2004 to 2009, the incidence in native Dutch/Western in Amsterdam was 1.6/100,000 (reference for IRR), in FGM was 4.3/100,000 (IRR of 2.7, 95% CI:1.8-4.2) and in Dutch-born second generation migrants (SGM) was 3.7/100,000 (IRR:2.4, 95% CI:1.2-4.7). CONCLUSION: Incidence of acute hepatitis B in Amsterdam in FGM and SGM is higher than in the native Dutch population. Low-endemic countries with migrant populations from HBV-endemic areas should consider offering screening and vaccination to both FGM and SGM.

High HIV incidence among MSM prescribed postexposure prophylaxis, 2000-2009: indications for ongoing sexual risk behaviour.

OBJECTIVE: To determine (trends in) HIV incidence among MSM\ who have recently had postexposure prophylaxis (PEP) prescribed in Amsterdam, compared with MSM participating in the Amsterdam Cohort Studies (ACS). DESIGN AND METHODS: We used data from MSM who were prescribed PEP in Amsterdam between 2000 and 2009, who were HIV-negative at the time of PEP prescription and had follow-up HIV testing 3 and/or 6 months after PEP prescription (n = 395). For comparison, cohort data from MSM participating in the ACS in the same period were used (n = 782). Poisson log-linear regression analyses were performed to model trends in HIV incidence and identify differences in HIV incidence between both cohorts at different time points. RESULTS: Between 2000 and 2009, among MSM who were prescribed PEP, an overall HIV incidence of 6.4 [95% confidence interval (CI) 3.4-11.2] per 100 person-years was found, compared with an HIV incidence of 1.6 (95% CI 1.3-2.1) per 100 person-years among MSM participating in the ACS (P < 0.01). In both cohorts, an increasing trend in HIV incidence over time was observed [incidence rate ratio (IRR(per calendar year)) 1.3 (95% CI 0.9-1.7) and 1.1 (95% CI 1.0-1.2) among MSM prescribed PEP and MSM of the ACS, respectively]. The difference in HIV incidence between both cohorts was most evident in more recent years [IRR(PEP versus ACS in 2009) 4.8 (95% CI 2.0-11.5)]. CONCLUSION: Particularly in more recent years, MSM recently prescribed PEP had a higher HIV incidence compared with MSM participating in the ACS, indicating ongoing sexual risk behaviour.