Hepatitis A Vaccination of Men Who Have Sex With Men -- Atlanta, Georgia, 1996-1997
September 4, 1998
Outbreaks of hepatitis A among men who have sex with men (MSM) are a recurring problem in many large cities in the industrialized world (1,2). Because MSM are at high risk for acquiring hepatitis A, in 1995 the Advisory Committee on Immunization Practices (ACIP) recommended that MSM be vaccinated against hepatitis A (3). These recommendations have not been implemented widely, even in outbreak settings. This report summarizes the investigation of an ongoing outbreak of hepatitis A among MSM in Atlanta, Georgia, and a public health vaccination campaign in response to the outbreak.
Hepatitis A has been a reportable disease in Georgia since 1978. However, reports are passively collected from laboratories and clinical sites. In March 1996, the state and local health departments noted an increase in hepatitis A cases reported in the Atlanta area. The Georgia Division of Public Health informed local physicians of the outbreak and encouraged them to educate their patients about the risk for hepatitis A transmission and to offer the hepatitis A vaccine to MSM because of anecdotal information linking the outbreak to MSM.
To improve surveillance, a large laboratory, which performs more than 50% of all hepatitis A testing in Georgia, agreed to report all new cases of hepatitis A (based on IgM anti-hepatitis A virus positivity) to the state. From January through September 1996, 222 cases of hepatitis A were reported in Atlanta residents, a 730% increase compared with the annual average of 27 cases during 1993-1995. Evidence that the outbreak was confined primarily to the MSM population of Atlanta included that 1) the proportion of cases that occurred in men aged 20-49 years increased from 41% of cases during 1993-1995 to 74% of cases during 1996 (p<0.01); 2) approximately 75% of male patients self-identified as MSM; and 3) a large proportion of the cases were being diagnosed at medical practices predominantly serving MSM.
In September 1996, state and county health officials, in collaboration with community leaders, planned a hepatitis A vaccination campaign focused specifically on MSM residing in Atlanta. Because one dose of hepatitis A vaccine provides 94% of recipients protection for at least 1 year (4), the first of the two-shot series was provided free by the health department. Vaccination sites included public health clinics, community physicians serving predominantly MSM, bars and sports events, and a community health van stationed on Saturdays at a shopping area popular with the MSM community.
The vaccine campaign and an associated education campaign were promoted through targeted physicians, articles and advertisements in local newspapers that are aimed at homosexuals, community organizations, and pamphlets and fliers distributed to local businesses serving homosexuals. From November 1996 through November 1997, approximately 3000 MSM received one dose of hepatitis A vaccine directly through the campaign, representing approximately 10% of the at-risk population in Atlanta.
From January 1996 through November 1997, 735 cases of hepatitis A were identified in the four largest counties (i.e., Cobb, DeKalb, Fulton, and Gwinnett counties) in the metropolitan Atlanta area; 492 occurred in men aged 20-49 years (Figure 1). The number of cases of acute hepatitis A in men aged 20-49 years identified each month did not change substantially after the outbreak began. During December 1996-April 1997 (the 5-month period following initiation of the vaccine campaign), reported cases of hepatitis A in adult men decreased 16% compared with June 1996-October 1996 (the 5-month period preceding the campaign). Two hepatitis A outbreaks in May 1997 associated with restaurants serving the general population accounted for the increase in cases.
The demographic characteristics of persons reported with hepatitis A suggest that the outbreak continued in the MSM population of Atlanta through November 1997. From April through November 1997, most (61%) reported cases in metropolitan Atlanta occurred in men aged 20-49 years, compared with 26% of cases in Georgia (p<0.01). The decline in cases from 74% to 61% can be explained by two restaurant outbreaks, in which adult women were as likely to be affected as men.
To better understand the response of the community to this outbreak and vaccination campaign, an anonymous survey of MSM was conducted at various community events and sites during June-August 1997. Sites were selected based on an expected participation rate of at least 50%. A total of 255 men were approached and asked to participate; 210 responded to the survey.
Of the 210 MSM surveyed, 138 (66%) were aware of the recent hepatitis A outbreak in Atlanta; most (73 [53%] of 138) learned of the outbreak from one of the articles or advertisements in an Atlanta newspaper aimed at homosexuals. Of 178 men who had not been previously vaccinated or had no history of hepatitis A (i.e., nonimmune), 34 (19%) received the hepatitis A vaccine during the campaign. Most (23 [68%] of 34) decided to receive the vaccine because of fear of the disease and/or because they felt at risk for acquiring the virus. The most common reasons for not receiving the vaccine included 1) never got around to it (26%), 2) did not believe they were at risk (26%), and 3) never heard there was a hepatitis A problem (23%). Of the 144 nonimmune men who did not receive the vaccine, 81 (56%) reported high-risk sexual behaviors, and 77 (54%) reported seeing a nonemergency department physician during the previous year.
Vaccination programs targeted to persons in age groups other than infants historically have been difficult to implement because many adolescents and adults do not visit health-care providers for preventive health care. Vaccination programs targeting persons with risk behaviors present difficult challenges because persons may not self-identify as having high-risk behavior or they may not perceive themselves to be at high risk. In addition, health-care providers often do not ask about risk behaviors during health-care visits, resulting in missed opportunities to vaccinate persons in high-risk groups.
Hepatitis A vaccine became commercially available in 1995. The occurrence of outbreaks among MSM and the high prevalence and incidence of hepatitis A among MSM compared with the general population resulted in the ACIP recommending routine hepatitis A vaccination of MSM.
In the vaccine campaign in Atlanta, community-based organizations and local newspapers were effective in raising awareness about the outbreak and the availability of vaccine. In addition to educational efforts, hepatitis A vaccine should be offered at multiple sites that provide health care to MSM, including primary-care clinics, specialty clinics, sexually transmitted diseases clinics, and human immunodeficiency virus testing and counseling sites. In the Atlanta outbreak, most vaccinations were administered through a mobile health van or at bars, suggesting that innovative approaches to reach high-risk adult populations can be effective. Efforts to vaccinate at-risk populations should be maintained at all times to prevent recurring outbreaks among MSM and to protect persons at risk.
2. Communicable Disease Network -- Australia. Communicable disease surveillance. CDI 1996;20:409.
3. CDC. Prevention of hepatitis through active or passive immunization. MMWR 1996;45:(no. RR-15).
4. Clemens R, Safary A, Hepburn A. Clinical experience with an inactivated hepatitis A vaccine. J Infect Dis 1995;171:44-9.
5. McMahon BJ, Beller M, Williams J, Scholoss M, Tanttila H, Bulkow L. A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine. Arch Pediatr Adolesc Med 1996;150:733-9. [Abstract]
6. Craig AS, Moore W, Schnaffner W, et al. Use of hepatitis A vaccine to control a community wide outbreak [Abstract 279]. Clin Infect Dis 1996;23:911.
This article was provided by U.S. Centers for Disease Control and Prevention. It is a part of the publication Morbidity and Mortality Weekly Report. Visit the CDC's website to find out more about their activities, publications and services.