Nancy A. Melville
December 2, 2011 (Washington, DC) — Patients in methadone maintenance treatment facilities, known to be at higher risk for hepatitis C virus (HCV) infection than the general population, might also have higher rates of vaccine-preventable hepatitis A (HAV) and B (HBV) infection, according to research presented here at the American Public Health Association 139th Annual Meeting.
HCV, which is often asymptomatic, can be particularly dangerous when patients are coinfected with HAV or HBV, potentially causing more acute liver disease, fulminant hepatitis, hepatocellular carcinoma, and/or death, investigators from the Beth Israel Medical Center in New York City told meeting attendees.
In an effort to determine the prevalence of the diseases at a methadone maintenance treatment program at Beth Israel, the researchers evaluated 8060 patients who were screened from June 2007 to July 2009.
They found that 35% of patients were susceptible to HBV, 15% had isolated HBV core antibody (cAb), 1% were positive for HBV surface antigen, 27% were immune to HBV because of natural disease, 23% were immune to HBV because of vaccination, and 35% were susceptible to HAV.
"Overall, 50% were susceptible to HAV, HBV, or both," the authors write.
In addition, of the 56% of patients who were positive for the HCV antibody, 17% were susceptible to HBV and 22% were susceptible to HAV, representing a very high-risk population.
Overall, 31% who were positive for the HCV antibody were susceptible to HAV and/or HBV.
Of the 1029 patients positive for HBV cAb who were also screened for the HCV antibody, 954 (93%) were positive for the HCV antibody, and 24% of the HCV-positive patients had isolated HBV cAb positivity (24% vs 2%; P < .0001; odds ratio, 12.5; 95% confidence interval, 9.8 to 16.0).
The findings highlight a heightened susceptibility of the substance-abusing generation born before hepatitis A and B vaccines became standard for newborns, said Catherine L. Troisi, PhD, who moderated the session.
"The average age was around 50. What this shows is they were likely not vaccinated at birth and, because of their drug use, there is a heightened risk," said Dr. Troisi, who is from the division of management, policy, and community health at the University of Texas School of Public Health in Houston.
"The fact that so many were hepatitis C–positive, which you cannot vaccinate against, indicates that they should be vaccinated against A and B, because those diseases can place additional assaults on the liver."
Dr. Troisi added that one of the more unusual findings is that 15% were positive for isolated HBV cAb. "It's unclear what that means," she said. "It's higher than you would find normally. It may be that these people had occult hepatitis B [with undetectable hepatitis B antigen]."
Vaccinating populations at methadone maintenance clinics has always been a challenge, but Dr. Troisi noted she had success in one study with an accelerated vaccination schedule, in which patients were vaccinated at 0, 1, and 2 months, instead of the typical 0, 1, and 6 months.
"Using an accelerated schedule is easier because you don't have to find people 6 months later," she said. "But it's hard, especially with hepatitis C, because if they're using needles, they can become positive pretty quickly, and you'd like to vaccinate them against hepatitis A and B before they are infected with C."
The authors and Dr. Troisi have disclosed no relevant financial relationships.
American Public Health Association (APHA) 139th Annual Meeting: Abstract 237717. Presented October 31, 2011.
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