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Outbreak of Hepatitis A among Men Who Have Sex with Men: Implications for Hepatitis A Vaccination Strategies
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The Journal of Infectious Diseases 2003;187:1235-1240
Suzanne M. Cotter,1,a Stephanie Sansom,2,a Teresa Long,3 Elizabeth Koch,4 Scott Kellerman,1,a Forrest Smith,4 Francisco Averhoff,2,a and Beth P. Bell1
1Division of Viral Hepatitis, National Center for Infectious Diseases, and 2National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia; 3Columbus Department of Health and 4Ohio State Department of Health, Columbus
"...in some MSM communities, the majority of hepatitis A cases cannot be attributed to specific high-risk sex practices.... could have resulted from other contact by which fecal-oral transmission can occur, such as nonsexual close personal contact or consumption of contaminated food... Although it was not specifically evaluated, our investigation suggests that hepatitis A vaccination coverage among MSM was low. Few participants were aware of the availability of hepatitis A vaccine or had ever been recommended it..... similar findings with respect to hepatitis B vaccination have been reported in this population..... Our findings also suggest that many MSM could be readily accessed for vaccination in private providers' offices.... To improve hepatitis A and hepatitis B vaccination coverage among MSM, providers should be made aware of the importance of vaccinating their MSM patients, and patients should be made aware of the vaccine's availability and the importance of requesting it when they seek routine health care"
Between November 1998 and May 1999, 136 cases of hepatitis A were reported in Columbus, Ohio, a 325% increase over the average of 32 cases reported annually during the same period for the each of the previous 5 years. The median age of case patients was 33 years (range, 585 years), 108 (80%) were white, and 118 (87%) were male. Incidence among men was higher than that among women (24.6 cases/100,000 population vs. 3.5 cases/100,000 population). Twenty-six (19%) patients were hospitalized, and 1 case patient died of fulminant hepatic failure secondary to acute hepatitis A.
Despite the licensure of hepatitis A vaccine in 1995, hepatitis A remains one of the most frequently reported diseases in the United States that is preventable by vaccine. Most cases occur in the context of community-wide outbreaks, during which infection is transmitted primarily from person to person in households and extended family settings. Recognized risk factors include contact with an infected person, contact with a day care center, the use of illicit drugs, being a man who has sex with men (MSM), and international travel. However, 40%50% of reported cases do not involve a recognized risk factor.
Periodic hepatitis A outbreaks among MSM have been reported during the past 3 decades in the United States, Canada, Europe, and Australia. In 1996, the Advisory Committee on Immunization Practices (ACIP) recommended hepatitis A vaccination for sexually active MSM [2]. Between January and March 1999, the Columbus city and Franklin County, Ohio, health departments noted an increase in hepatitis A cases, compared with previous years. Preliminary investigation indicated that MSM were disproportionately affected. We studied this community-wide hepatitis A outbreak, evaluated the risk factors for hepatitis A among MSM, and looked for potential opportunities to deliver the hepatitis A vaccine to MSM.
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, 1.0448.02); neither number of sex partners nor any sex practice was associated with illness.
Household or sexual contact with a hepatitis A case in the 26 weeks before onset of illness (i.e., the referent exposure period) was the only risk factor associated with hepatitis A (OR, 6.15; 95% CI, 1.0448.02) but was reported by only 6 (13%) case patients. There was no association between hepatitis A and other recognized risk factors, including international travel, contact with day care, or illicit drug use (data not shown). There also was no association between hepatitis A and reporting of anonymous sex, visiting the local or any bathhouse, or specific sex practices, such as having digital-anal or oral-anal sex.
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.
Potential access points for vaccination. The majority of case patients and control subjects reported having health insurance, having a regular health care provider, and seeing their health care provider at least once a year. Case patients were more likely than control subjects to have informed their health care provider of their sexual preference (P < .001). The majority of case patients and control subjects reported having ever visited a human immunodeficiency virus (HIV) testing site, and approximately one-third reported ever visiting a sexually transmitted disease (STD) clinic.
Knowledge of hepatitis A and willingness to pay for vaccine. Among control subjects recruited from social settings (bars and coffee houses), 54 (78%) had heard of hepatitis A. However, only 21 (31%) were aware of the hepatitis A vaccine. Fifty-six (93%) control subjects said they would get the vaccine if their health care provider recommended it, and most (74%) expressed a willingness to pay $25 per dose of vaccine .
Discussion by authors
Among MSM, household or sexual contact with a hepatitis A case patient was the only risk factor associated with hepatitis A, but this exposure accounted for a small proportion of cases. We did not identify any sex practices associated with hepatitis A, and the majority of case patients reported 1 or no sex partner during the referent exposure period. In studies of other outbreaks among MSM, specific sex practices, including >1 anonymous sex partner, group sex, oral-anal or digital-anal sex, or visiting darkrooms (similar to bathhouses) and saunas, were associated with illness. In seroprevalence studies, a greater number of sex partners , longer duration of sexual activity, frequent oral-anal contact, and serological evidence of other STDs were associated with HAV infection. The results of our investigation and those of other studies suggest that risk factors that promote the transmission of HAV among MSM may vary and that, at least in some MSM communities, the majority of hepatitis A cases cannot be attributed to specific high-risk sex practices [24, 25]. Unlike many other infections that disproportionately affect MSM, HAV infection from sexual contact results from fecal-oral transmission. Thus, infections could have resulted from other contact by which fecal-oral transmission can occur, such as nonsexual close personal contact or consumption of contaminated food. We attempted, but ultimately were unable, to evaluate the possible contribution of nonsexual potential sources of HAV transmission, such as foodborne exposures. The role of unrecognized person-to-person and other nonsexual transmission of HAV among close social networks during hepatitis A outbreaks among MSM merits further investigation.
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