Objective: The goal was to determine the prevalence of acute hepatitis A virus (HAV) infection and immunity among internationally adopted children.
Methods: Children seen at the International Adoption Center between September 25, 2006, and September 30, 2008, and were screened for HAV within 4 months after their arrival in the United States were eligible for the study. The age- and country-specific prevalence of acute HAV infection and immunity were determined.
Results: Overall, 288 children underwent HAV serological testing. Of the 279 with total HAV serological results, 29% had positive findings. Immunity varied according to region and country. The prevalence was lowest among children born in Asia/Pacific Rim region (17%) and highest among children born in Africa (72%). Only 13% of children <2 years of age were immune, compared with 80% of children 12 to 17 years of age (P = .002). Increasing age and birth region were associated independently with immunity. Positive HAV immunoglobulin M test results were found for 3 (1%) of 270 children; all were without symptoms. Their ages were 18, 27, and 41 months, and they were born in Kazakhstan, Russia, and the Latin America/Caribbean region, respectively. The father of 1 child developed HAV infection after arriving home.
Conclusions: HAV immunity among internationally adopted children varied according to age and country of origin; 1% had acute infections. HAV screening is useful for determination of the need for HAV immunization and for prevention of transmission to family members and close contacts.