The findings and conclusions in these presentations have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy.

Tuesday, May 9, 2006 - 10:30 AM

Identification of risk criteria predictive of HIV seroconversion in men who have sex with men

Timothy William Menza, Department of Epidemiology, Center for AIDS and STD, University of Washington, Harborview Medical Center, 325 Ninth Ave, Box 359931, Seattle, WA, USA and Matthew R. Golden, Infectious Diseases, Public Health - Seattle & King County, University of Washington, Harborview Medical Center, 325 9th Ave., Box 359777, Seattle, WA, USA.

The clinical and preventive care of MSM seen in STD clinics is currently relatively uniform, with little specific follow-up directed toward those at greatest risk. Intensified interventions will require identification of the highest risk MSM.

To estimate HIV incidence in MSM STD clinic patients, and devise criteria to identify the highest risk men for potential intensified intervention.

We identified MSM serially HIV tested in the PHSKC STD clinic between 2001 and 2005, calculated HIV incidence in the population, and developed criteria to identify high-risk men for intensified follow-up.

A total of 2698 MSM were seen in the clinic, of whom 954 tested for HIV more than once. Forty-six seroconversions were identified over 1715 person-years (incidence=2.9 per 100 person-years, 95%CI: 1.96-3.58). On multivariate analysis, incident HIV infection was associated with the following factors identified at initial testing visit: methamphetamine use (HR=1.87), syphilis (HR=3.38), gonorrhea (HR=3.49), and sex with a partner of discordant or unknown HIV status (HR=2.33). The 45% of men with one or more of these risk factors accounted for 73% of the cases of HIV and 40% of the total person-time. Men with any of the associated risk criteria experienced an incidence of 6.4 per 100 person-years (95%CI: 4.6-8.7), while men with none of the identified risk factors had an incidence of 2.1 per 100 person-years (95%CI: 1.2-3.5).

Easily ascertained risk factors can identify MSM STD clinic patients at very high risk of acquiring HIV.

Seroconversion risk criteria can be used to identify candidate populations for intensified prevention interventions, such as scheduled follow-up HIV/STD testing and methamphetamine treatment interventions.