Nitrite Inhalant Use among Young Gay and Bisexual Men in Vancouver during a Period of Increasing HIV Incidence

Background: Nitrite inhalants ("poppers") are peripheral vasodilators which, since the beginningof the epidemic, have been known to increase risk for acquiring HIV infection among men who havesex with men (MSM). However, few studies in recent years have characterized use. From 1999 to2004, new HIV diagnoses among MSM in British Columbia increased 78%, prompting us to examinethe prevalence and correlates of this modifiable HIV risk factor.Methods: Self-administered questionnaires were completed between October 2002 and May2004 as part of an open cohort study of HIV-seronegative young MSM. We measured nitriteinhalant use during the previous year and use during sexual encounters with casual partnersspecifically. Correlates of use were identified using odds ratios.Results: Among 354 MSM surveyed, 31.6% reported any use during the previous year. Nitriteinhalant use during sexual encounters was reported by 22.9% of men and was strongly associatedwith having casual partners, with greater numbers of casual partners (including those with positiveor unknown serostatus) and with anal intercourse with casual partners. Nitrite inhalant use wasnot associated with non-use of condoms with casual sexual partners per se.Conclusion: Contemporary use of nitrite inhalants amongst young MSM is common and a strongindicator of anal intercourse with casual sexual partners. Since use appears to increase theprobability of infection following exposure to HIV, efforts to reduce the use of nitrite inhalantsamong MSM should be a very high priority among HIV prevention strategies.