A Comparison of Men Who Have Sex with Men, People Who Inject Drugs and High-Risk Heterosexuals' Risk for HIV Infection, San Francisco.

HIV in the United States is concentrated in populations such as men who have sex with men (MSM), people who inject drugs (PWID), women of color and people living in poverty. These populations are labeled high-risk for HIV infection because of the higher levels of HIV or HIV risk taking behaviors seen in these groups compared to other sub-populations. It is also possible that a group may engage in behaviors that are "high-risk" for HIV infection but never become infected since HIV is not present or not present to a great extent in their social or sexual networks. We analyzed samples of MSM, PWID and high-risk heterosexuals (HRH) collected through the National HIV Behavioral Surveillance (NHBS) system in San Francisco to examine HIV risk taking and HIV burden to determine if the label "high-risk" is appropriately applied. NHBS samples MSM using time location sampling and PWID and HRH using Respondent Driven Sampling. We sampled 508 MSM in 2011, 570 PWID in 2012 and 267 HRH in 2013. There were, as expected, differences in demographic characteristics across the three groups. HRH had a greater number of high-risk behaviors compared to MSM and PWID but had the lowest HIV prevalence. Focusing on risk behavior alone to label populations without considering the background HIV prevalence in communities, the types of risks engaged in and actual HIV infections may obscure which populations truly merit the label "high-risk" for HIV infection.

International travel among HIV-positive and HIV-negative men who have sex with men, San Francisco, USA.

We measured the prevalence of international travel, the demographic and risk profile of international travellers and risk and preventive behaviours of travellers among HIV-negative and HIV-positive men who have sex with men (MSM), based in San Francisco, CA, USA, through the addition of questions to the local implementation of the National HIV Behavioral Surveillance survey in 2008. Of 270 MSM participating in the survey, slightly more than one-quarter (26.3%) had travelled internationally in the last year. Those with a history of international travel were more likely to be foreign born, of a higher socioeconomic status and HIV uninfected. Of eight HIV-positive MSM who travelled internationally (11.3% of HIV-positive MSM), all were on antiretroviral therapy and only three recalled being vaccinated for hepatitis A and B. Human papillomavirus infection was also higher among international travellers. Travel health services must be improved to address special needs of this population of international travellers.