Incident Hepatitis B Virus Infection in HIV-Infected and HIV-Uninfected Men Who Have Sex With Men From Pre-HAART to HAART Periods: A Cohort Study.

Worldwide, chronic hepatitis B virus (HBV) infection is the leading cause of end-stage liver disease and hepatocellular carcinoma (1). In the United States, sexual transmission among men who have sex with men (MSM) is a principal cause of incident infection. Approximately 15% to 25% of new HBV infections in the United States are among MSM, although this group accounts for only 2% of the U.S. population (2, 3). Although the HBV vaccine has greater than 95% efficacy and was first recommended in 1982 by the Advisory Committee on Immunization Practices for MSM, vaccination rates remain low in MSM (4, 5). Little is known about prospective trends and risk factors for incident HBV infection in MSM, and this knowledge is needed to refocus efforts to prevent HBV infection in this population. Incidence of HBV infection has declined in the general population (6), but data suggest an increasing incidence in HIV-infected persons (7). In a study of HIV-infected U.S. military personnel and their dependents, a decline in incidence of HBV infection from 1997 to 2000 was followed by an increase from 2000 to 2008, with men having an 8-fold increased risk for incident HBV infection compared with women (7). In HIV-infected persons, lamivudine- or tenofovir disoproxil fumarate (TDF)–containing antiretroviral therapy has been associated with reduced incidence of HBV infection (7–9). To our knowledge, no systematic studies of incident HBV infection in prospectively followed cohorts of MSM have included both HIV-infected and HIV-uninfected persons to determine the effect of highly active antiretroviral therapy (HAART) on the incidence of HBV infection. The Multicenter AIDS Cohort Study (MACS), a prospectively followed cohort of MSM established in 1984, is ideal to investigate incident HBV infection among HIV-infected and HIV-uninfected MSM because the cohort has been followed systematically since the beginning of the HIV epidemic. To determine risk factors for and trends in incident HBV infection in MSM since the early HIV epidemic, we tested prospectively collected specimens from men in MACS without evidence of a previous HBV infection at study entry.