Currently, the CDC estimates there are 1.2 million Americans chronically infected with hepatitis B virus (HBV), a number that hasn’t changed for decades. The Hepatitis B Foundation (HBF), however, speculates that this number does not accurately reflect the true number of chronic infections based on their discussions with experts in the field and initial research findings.

Over the past 10 years, millions of Asian immigrants have lawfully entered the country and many of them have emigrated from countries where the hepatitis B infection rate is over 10%.

According to 2000 U.S. Census data, there are now 12.6 million Asians living in the country. Based on these facts, one would have expected to see a significant increase in the number of chronic HBV infections. Yet, the official number has remained constant.

According to Chari Cohen, MPH, HBF program coordinator, the number hasn’t changed because the U.S. estimate for chronic hepatitis B infections is derived from the National Health and Nutrition Education Survey (NHANES). In this survey, the Asian and Pacific Islander (API) ethnic groups, which are most affected by hepatitis B, are significantly under-represented.

Based on immigration and census data, and the known prevalence rates for hepatitis B in Asian countries, Ms. Cohen’s preliminary calculations revealed a stunning result - if the API group is fully included in the surveillance equation, then the true number of chronic HBV infections in the U.S. could exceed two million!

The possibility that more than one million affected immigrants might have unknowingly been overlooked by official hepatitis B surveillance studies have profound implications since health care policy and budgets are influenced by these kinds of statistics.

If these “invisible immigrants” have been omitted from a key public health tracking system that informs decision makers on how to spend U.S. health dollars, then this major oversight must be corrected. To address the issue, Ms. Cohen is spearheading the HBF’s new B Counted program.

Identifying the true number of chronic hepatitis B infections is a particularly urgent public health matter in light of the growing incidence of liver cancer. Liver cancer has been identified as the fastest growing cancer in the U.S. by the National Cancer Institute. This finding is especially significant because other types of cancer have decreased over the past decade.

With 80% of the world’s liver cancer caused by chronic hepatitis B, the rising incidence of liver cancer in the U.S. underscores the need to make sure HBV surveillance studies are accurate. It is imperative that the true number of chronic hepatitis B infections be attained. The U.S. cannot be taken by surprise by this epidemic, and the additional one million “invisible” Americans must be counted.

BInformed, Summer 2006.