Immunity to hepatitis A and hepatitis B in Indian and Chinese immigrants seen in a travel clinic in Massachusetts, United States.

Immigrants to the United States from developing countries have a higher probability of previous infection with hepatitis A virus (HAV) and/or hepatitis B virus in their countries of origin. Prior knowledge of hepatitis A and B seroprevalence in this population may aid in determining the need for pretravel immunizations when these individuals travel to endemic regions. We conducted a retrospective analysis of hepatitis A and B serologies in a travel clinic population (from March 1999 through September 2002) to determine the seroprevalence in our predominantly highly educated foreign-born subjects. All our patients who had immigrated from China and India and who were older than 60 years (born on or before 1940) were immune to hepatitis A. The Indian and Chinese subjects who were anti-HAV positive were also significantly older than the anti-HAV negative group. In addition, in our Indian study group, the hepatitis A-seropositive individuals first left India at a significantly older age than the hepatitis A-seronegative group (mean age 22.7 years vs 11.4 years, p < 0.05). Our small sample size of Chinese subjects may not have permitted a statistically significant difference to be detected for hepatitis A seroprevalence and age at departure from their country of origin. These results have helped tailor our recommendations for pretravel immunizations for our groups of foreign-born individuals planning to visit endemic areas. Individuals born in China or India on or before 1940 are likely to have preexisting antibody to hepatitis A and probably do not need the vaccine when they travel. Younger individuals may elect to have a hepatitis A antibody titer checked before getting the vaccine.