Outbreak of hepatitis A among men who have sex with men: implications for hepatitis A vaccination strategies.

Between November 1998 and May 1999, 136 cases of hepatitis A were reported in Columbus, Ohio. Eighty-nine (65%) case patients were reinterviewed. Of 74 male case patients, 47 (66%) were men who have sex with men (MSM). These 47 MSM were compared with 88 MSM control subjects, to identify risk factors for infection and potential opportunities for vaccination. During the exposure period, 6 (13%) case patients reported contact with a person who had hepatitis A, compared with 2 (2%) control subjects (odds ratio, 6.15; 95% confidence interval, 1.04-48.02); neither number of sex partners nor any sex practice was associated with illness. Most case patients and control subjects (68% and 77%, respectively) saw a health care provider at least annually, and 93% of control subjects reported a willingness to receive hepatitis A vaccine. MSM are accessible and amenable to vaccination; increased efforts are needed to provide vaccination, regardless of reported sex practices.