MSM newly diagnosed with HIV in New York City: Differences in behaviors and partner characteristics by age group

Background: New HIV diagnoses in NYC have decreased in overall number, but become increasingly concentrated among MSM (from 28% in 2001 to 43% in 2009). Among newly diagnosed MSM, time trends in diagnosis rates differ by age group, with those among MSM ≥30 years old (OMSM) declining and those among MSM <30 years old (YMSM) increasing. Methods: NYC health department (DOHMH) collected information on demographics, sexual risk and sex partners on HIV-infected MSM reported for partner services from 2007 to 2008. We used chi-square tests, t-tests and Wilcoxon rank-sum tests to compare YMSM and OMSM. Results: Of 3300 MSM newly diagnosed with HIV, DOHMH interviewed 339 for partner services (12% overall, 182 YMSM, 157 OMSM), of whom 91% were black or Hispanic. YMSM reported more sex partners in the past 12 months compared to OMSM (mean: 4.4 vs. 4.0 partners, P<.01), and were more likely to have had an STI (28.6% vs. 14.6%, P<.01).YMSM identified as gay more often than OMSM (69.2% vs. 58.0%, P<0.01).YMSM were equally likely as OMSM to have same-race partners, though overall, black MSM were more likely to have same-race partners (73.4%) than Hispanic MSM (36.2%). Conclusions: Behavioral and partner characteristics of young versus older MSM newly-diagnosed with HIV differed, with important implications for HIV prevention efforts. YMSM newly diagnosed with HIV had characteristics suggesting more recent high-risk sex, which if persistent following diagnosis, suggests a particular need to intensify secondary prevention efforts among young MSM.