There is a substantial opportunity to reduce the prevalence of chronic hepatitis B virus (HBV) infection in the United States by more rigorous screening and vaccination.1 The list of groups that should be screened, according to guidelines from the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices, includes individuals born outside the United States in Asia, the Pacific Islands, Africa, and other regions with intermediate to high chronic hepatitis B endemicity (>2%); pregnant women; and nonvaccinated adults with risk factors including exposure (occupational, travel, or health care–related), high-risk sexual activity, and injection-drug use.2 Regional variations in chronic HBV infection, traced to differences in risk factor prevalence, have been reported.1 Recognizing these risk differences is important in the prevention and treatment of chronic HBV and its complications, including hepatocellular carcinoma.

“The frequency of chronic HBV infection can be higher by an order of magnitude or even more in fairly well-defined groups, so the recognition of risk groups is sensible,” said Ira M. Jacobson, MD, a gastroenterologist based in New York City. Dr. Jacobson supports the guidelines and indicated that guidelines are effective only when physicians act on the recommendations. Several groups, including the CDC, that have developed comprehensive strategies to eliminate HBV transmission in the United States, consider HBV screening in targeted risk groups to be an urgent health priority.2

“With the number of new infections remaining steady despite the availability of a vaccine, and the significant rise of primary liver cancer in the USA, it is imperative that hepatitis B be prioritized as an important public health concern,” according to a published statement from the Hepatitis B Foundation.3

The regional differences in risk for HBV are driven by the distribution of risk groups. In the case of immigrants, it is important to recognize that this can include US-born children of immigrants. For example, a study of US-born children of Asian immigrants found an HBV prevalence rate of 1.4%, which was about 3 times greater than expected.4 In this study, which was conducted among adolescents enrolled in a public university in California, the rate rose to 3.3% or approximately 10 times greater than the background rate in the Asian students born outside of the country.4

The regional variation in risk for HBV in the United States is influenced by the disproportionate composition of foreign-born individuals and populations with behavioral risk for infection.1 However, specific risk groups identified by the CDC should be rigorously screened regardless of region.

In the effort to control HBV transmission, preventing infection of children is a priority. About 95% of primary HBV infections in adults are self-limited.2 In contrast, about 90% of infants infected at birth develop chronic HBV and 30% of children infected after the perinatal period but before the age of 6 years develop chronic infection.5

These individuals not only face the risk for developing chronic HBV, including liver cancer, but also may potentially and unknowingly infect others.5 This high risk for developing chronic HBV in infancy underscores the CDC recommendation for universal screening for HBV among pregnant women.2

A critical time to prevent HBV transmission is at birth. “Vaccination programs in children and screening of pregnant women are critical components in the effort to reduce chronic HBV in the United States,” said Dr. Jacobson. Since some high-risk groups may not routinely see physicians, “special programs may be needed to reach these individuals,” he added.

Despite estimates that suggest that 1.4 to 2 million individuals in the United States have chronic HBV, only 400,000 to 600,000 have been diagnosed.6 The critical step toward reducing chronic HBV infection is more rigorous application of screening recommendations, including greater efforts to reach those individuals who have infrequent contact with the health care system.

References

     
  1. Weinbaum CM, Mast EE, Ward JW. Recommendations for identification and public health management of persons with chronic hepatitis B virus infection. Hepatology. 2009;49(5 suppl):S35-S44.
  2. Mast EE, Weinbaum CM, Fiore AE, et al. A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States. MMWR Recomm Rep. 2006;55(RR-16):1-33.
  3. Cohen C, Evans AA, London WT, Block J, Conti M, Block T. Underestimation of chronic hepatitis B virus infection in the United States of America. J Viral Hepat. 2008;15(1):12-13.
  4. Quang YN, Vu J, Yuk J, Li CS, Chen M, Bowlus CL. Prevalence of hepatitis B surface antigen in US-born and foreign-born Asian/Pacific Islander college students. J Am Coll Health. 2011;59(1):37-41.
  5. Hyams KC. Risks of chronicity following acute hepatitis B virus infection: a review. Clin Infect Dis. 1995;20(4):992-1000.
  6. Cohen C, Holmberg SD, McMahon BJ, et al. Is chronic hepatitis B being undertreated in the United States? J Viral Hepat. 2011; 18(6):377-383.
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