Immunization against hepatitis B virus (HBV) appears to be uncommon among young men who have sex with men, according to an analysis of findings from a survey conducted in six urban centers in 1998–2000.[1] Fewer than one in five respondents overall had been immunized; even among those who had a regular source of health care, the level of coverage was not substantially higher. Moreover, the data suggest that opportunities for men to be vaccinated often are missed: The vast majority of those who were susceptible to infection and had not been vaccinated had a regular source of care, had been tested for HIV infection or had had an STD diagnosis.
The 1998–2000 Young Men’s Survey was conducted among men aged 23–29 in Baltimore, Dallas, Miami, New York, Los Angeles and Seattle. Potential respondents were recruited at venues frequented by men who have sex with men. Those who agreed to participate completed a questionnaire covering their socioeconomic characteristics, health care use and risk-related behaviors; they also received prevention counseling and provided blood specimens, which were tested for markers of HBV infection and immunization. An earlier round of the survey, identical in design to the 1998–2000 effort but conducted among 15–22-year-olds, provides a basis for assessing trends.
A total of 2,834 men were included in the analyses. The sample was about evenly split between men aged 23–25 and those aged 26–29. Forty-nine percent of participants were white, 23% Hispanic and 17% black; the rest came from a variety of racial and ethnic backgrounds. Close to half were college graduates, and seven in 10 worked full-time. Ninety-five percent had had anal sex with a man, and 7% had injected drugs. The majority of men had never had an STD (73%), had been tested for HIV (89%), were HIV-negative (88%) and had a regular source of health care (63%). Two-thirds said that they had revealed their sexual orientation to fewer than half of their acquaintances.
Laboratory results showed evidence of HBV immunization in 17% of respondents, but chi-square and trend analyses revealed some variation by men’s characteristics. The prevalence of immunization was higher in Seattle than elsewhere (25% vs. 14–17%) and was higher among men who had disclosed their sexual orientation to at least half of their acquaintances than among those who had told fewer (19% vs. 14%). Participants who were HIV-negative had a higher prevalence of coverage than did those with HIV infection (18% vs. 12%), and respondents who had a regular source of health care were more likely than those who did not to show evidence of immunization (14–21% vs. 13%). Prevalence fell with increasing age (from 19% among 23-year-olds to 14% among 29-year-olds) and rose with increasing levels of education (from 9% among men who had not graduated from high school to 30% among those with more than 16 years of schooling). Results of a multiple logistic regression analysis confirmed that the likelihood of immunization was positively associated with level of education and negatively associated with age, and that Asians, whites, Seattle residents and men with a regular health care source had elevated odds of having been immunized.
Twenty-one percent of men in the sample tested positive for HBV markers, indicating a history of infection (although not necessarily current or chronic infection). The proportion varied widely, however. It was as low as 9% among men who had never had anal sex, but it reached roughly 30–35% in several groups (blacks, men with less than a high school education, those who had had an STD, those who reported having had more than 50 male partners and those who had used injection drugs) and was 46% among respondents who had HIV infection. Except for education, these characteristics remained significant predictors of a history of infection in multivariate analysis; the odds of having had HBV infection were about 2–3 times as high for men reporting these risk factors as for others.
Comparisons of the two rounds of survey results show little improvement in immunization coverage and a continuing trend of increasing prevalence of a history of infection with increasing age. Thirteen percent of participants in the later survey both had serologic evidence of immunization and reported having been vaccinated, compared with 9% of those in the earlier round. The proportion with a history of infection climbed from 2% among the youngest men in the first phase to 17% among the oldest; it went from 14% among 23-year-olds in the second phase to 31% among 29-year-olds.
Respondents whose bloodwork showed no markers for either HBV immunization or HBV infection were classified as susceptible to infection and unvaccinated; 62% of the sample were in this category. Among these men, 94% had a regular source of health care, 88% had had an HIV test and 22% had had an STD; in all, more than nine in 10 had had one of these potential opportunities to be vaccinated.
The analysts comment that the low prevalence of HBV immunization found in this sample belies many years of public health recommendations to vaccinate men who have sex with men against HBV and likely contributes to the trend of increasing prevalence of infection with increasing age. Given the links between sexual behavior and a history of infection among men who have sex with men, they conclude that the "ongoing failure" to prevent HBV infection in this population may result partly from "missed opportunities in HIV/STD prevention systems." Addressing such missed opportunities, they remark, could help eliminate transmission of this infection among men who have sex with men.
REFERENCE
1. Weinbaum CM et al., The Young Men’s Survey phase II: hepatitis B immunization and infection among young men who have sex with men, American Journal of Public Health, 2008, 98(5):839–845.