SAN DIEGO – The prevalence of hepatitis B virus among children aged 6-19 years declined significantly between 1994 and 2004, Annemarie Wasley, Sc.D., reported during a poster session at the annual meeting of the Infectious Diseases Society of America.
“We have seen significant declines among kids, which is evidence that the impact of universal vaccination is becoming apparent,” Dr. Wasley, an epidemiologist with the division of viral hepatitis at the Centers for Disease Control and Prevention, Atlanta, said in an interview.
The finding comes from a comparison of the National Health and Nutrition Examination Surveys (NHANES) from 1988-1994 and 1999-2004. The researchers tested 22,435 serum samples from NHANES 1999-2004 for antibody to hepatitis B virus (HBV) core antigen, and if positive, HBV surface antigen. The prevalence estimates were weighted to represent the United States population and age-adjusted to allow comparison between participants of the two surveys.
The overall prevalence of HBV was 4.8% in NHANES 1988-1994 and 5.4% in NHANES 1999-2004, a difference that was not statistically significant. However, the prevalence of HBV among 6- to -19-year-olds declined significantly, from 1.9% in NHANES 1988-1994 to 0.5% in NHANES 1999-2004.
She also reported that the prevalence of HBV infection among foreign-born children aged 6-19 years declined significantly from 12.8% in NHANES 1988-1994 to 2.0% in NHANES 1999-2004.
“The prevalence among foreign-born children is still significantly higher than for U.S.-born children, who have a prevalence of 0.4%, but this difference is much smaller than in previous surveys,” she said. “Some implementation of routine vaccination has been occurring in a stepwise manner in different parts of the globe. To see the impact of that in our data was a surprise. Vaccination of kids is having an impact here and globally. That's great news.”
An analysis of all age groups found that the HBV prevalence was higher among black NHANES 1999-2004 participants (12.8%) than in white (3.0%) and Mexican American (2.8%) participants.