Differences in risk behaviors and partnership patterns between younger and older men who have sex with men in New York City.

BACKGROUND: Men who have sex with men (MSM) account for a higher proportion of HIV diagnoses than any other risk group in the United States. Given that in NYC MSM younger than 30 years represent a growing proportion of new diagnoses among MSM, we examined differences between MSM by age.
METHODS: We analyzed NYC surveillance and partner services (PS) data for MSM newly diagnosed with HIV from January 2007 to December 2008. We compared demographics, HIV-related risk behaviors, and sexual partner characteristics between younger MSM (<30 years old) (YMSM) and MSM ≥30 years old.
RESULTS: Three hundred and thirty-six MSM were interviewed for PS (180 YMSM and 156 older MSM). MSM were mostly black or Hispanic (91%). YMSM were more likely than older MSM to report gay sexual identity (70% vs. 58%, P < 0.01), and a recent sexually transmitted infection (29% vs. 15%, P < 0.01). More YMSM named ≥1 male partner for HIV notification (66% vs. 36%, P < 0.01). YMSM were more likely than older MSM to name partners who were 5 or more years older (42% vs. 25%, P < 0.01). More YMSM tested for HIV at least once in the past 2 years than older MSM (66% vs. 40%, P < 0.01). DISCUSSION: Our study has identified important differences in HIV risk behaviors and sexual partnerships between YMSM and older MSM newly diagnosed with HIV. YMSM were more willing to provide the names of male sex partners for the purposes of partner notification than were older MSM, suggesting that PS may be particularly effective at identifying new cases of HIV.