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HBV found to be prevalent in US

Hepatitis B virus infection was found to be prevalent in U.S. households, according to a new analysis of the National Health and Nutrition Examination Survey, published in Hepatology.

Henry Roberts, PhD, division of viral hepatitis, CDC, and colleagues analyzed data from the National Health and Nutrition Examination Survey (NHANES) from three time periods; 1988 to 1994, 1999 to 2006 and 2007 to 2012 to address the current prevalence and burden of HBV in the U.S. Between 2011 and 2012, estimates of HBV prevalence among non-Hispanic Asians were oversampled.

“In the United States, the National Notifiable Disease System (NNDSS), … is the main way of ‘counting [HBV] cases,’ but it is a passive system,” the researchers wrote. “Not all states and localities report persons with chronic HBV infections and, of those who do, their ability to identify, verify, and report such cases is widely variable. … [The] CDC has relied on analysis of serum from about 5,000 U.S. residents each year from the National Health and Examination Survey, a survey representative of the U.S. non-institutionalized household population, to estimate the prevalence of HBV infection.”

The prevalence estimates were determined by serologic testing and analysis in people aged 6 years and older for antibody to hepatitis B core antigen (anti-HBc), “indicative of prior HBV infection; hepatitis B surface antigen, indicative of chronic or current infection; and antibody to hepatitis B surface antigen(anti-HBs), indicative of immunity from vaccination,” according to the research.

Overall prevalence of chronic HBV has remained consistent since 1999 (0.3%; 95% CI, 0.2%-0.4%). Since 1999, however, the prevalence of chronic HBV among non-Hispanic blacks has been between two- and threefold higher than the general population.

Between 2007 and 2012, 3.9% of people had anti-HBc, indicating approximately 10.8 million U.S. residents not institutionalized having ever been infected with HBV (95% CI, 9.4-12.2).

Approximately 3.1% of non-Hispanic Asians were chronically infected with HBV between 2011 and 2012, which indicated a 10-fold higher prevalence compared with the general population. The prevalence of vaccine-induced immunity increased by 16% since 1999.

“[This] is the result of implementing universal HBV vaccination of infants — with ‘catch-up’ vaccination of children and adolescents — starting in 1991,” the researchers wrote. “The increase in HBV vaccine-induced immunity were largely adults of at least 20 years of age, primarily in those aged 20 to 49 years.”

Additionally, the number of those protected from HBV contraction due to the vaccine rose from 57.8 million (95% CI, 55.4-60.1) to 68.5 million people (95% CI, 65.4-71.2).

“Despite increasing immune protection in young persons vaccinated in infancy, an analysis of chronic hepatitis B prevalence in racial and ethnic populations indicates that during 2011 and 2012, there were 847,000 HBV infections in the non-institutionalized U.S. population,” the researchers concluded. – by Melinda Stevens

Disclosures: The researchers report no relevant financial disclosures.