Lower hepatitis B virus immunity in adults, including those at high risk of infection
THURSDAY, March 3 (HealthDay News) -- Children and adolescents in the United States have high rates of immunity against hepatitis B virus (HBV), although adults have much lower rates, according to a study published in the March 1 issue of the Annals of Internal Medicine.
George N. Ioannou, B.M.B.Ch., from the Veterans Affairs Puget Sound Health Care System in Seattle, analyzed data on 39,787 participants of the National Health and Nutrition Examination Survey to assess the prevalence of HBV infection, exposure, and immunity in the United States. From 1999 to 2008, past exposure, prevalence, and associations of chronic HBV infection, and immunity status were determined in participants aged 2 years or older by detecting the presence of serum HBV surface antigen and serum antibody to hepatitis B surface and core antigen.
The investigators identified chronic HBV infection in 0.27 percent of people aged 6 or older, and 4.6 percent had been exposed to HBV. People aged 6 to 19 years had very low rates of infection and past exposure. These estimates were significantly lower than HBV exposure (5.1 percent) and infection (0.42 percent) estimates from 1988 to 1994. High rates of immunity were observed in children aged 2 years (68.6 percent). Much lower rates of immunity were observed in adults, including those at high risk for infection.
"A cohort of children and adolescents is growing up in the United States with high rates of immunity against HBV and very low rates of infection. Vaccination of high-risk adults should continue to be emphasized," the author writes.
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