HepA Vaccine: More Adoptee Contacts

ATLANTA — Hepatitis A vaccination should be given to all previously unvaccinated nontraveling individuals who will be in close personal contact with an internationally adopted child, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention voted at its winter meeting.

The unanimous vote is in line with the American Academy of Pediatrics' position and will be reflected in the upcoming edition of the Red Book, AAP liaison Dr. Joseph A. Bocchini Jr. said in an interview.

According to the statement approved by ACIP, when adoption is planned for a child from a country of high or intermediate hepatitis endemicity, persons who will have close personal contact with the adoptee during the first 60 days following arrival of the adoptee in the United States should be identified.

The first dose of hepatitis A vaccine should be administered as soon as the adoption is planned, and ideally the first two doses given at least 2 weeks prior to the arrival of the adoptee.

Previous ACIP recommendations called for vaccination of only adoptive parents and others who actually travel to the country with high or intermediate hepatitis A endemicity, said Dr. Sandra Chaves of the CDC Division of Viral Hepatitis.

The issue came to the CDC's attention in June 2007 when a 51-year-old grandmother of 12-month-old adopted twins developed fatal fulminant hepatitis A. The twins were not jaundiced, but were confirmed to have hepatitis A. That case prompted further investigation, with the discovery of 20 additional cases of hepatitis A among nontraveling contacts of international adoptees from six states during 2006-2007, Dr. Chaves commented.

In one instance, a 10-month-old nonjaundiced adoptee was the source of infection for 12 other nontraveling contacts, including 6 household members and 2 extended family members.

The proportion of hepatitis A-infected individuals who are asymptomatic is 70% among children younger than aged 6 years, compared with 20%-50% of infected children aged 6-17 years. The ACIP considered recommending vaccination of contacts of only those adoptees younger than 6 years, but ultimately voted to include contacts of adoptees in all age groups.

Countries of origin of international adoptees have shifted over the years. South Korea predominated in 1990, while Russia and China became more frequent sources of adopted children around 2000. Guatemala now has surpassed China, although the two each account for a little over 20%.

However, nearly all of the foreign countries from which Americans adopt children are endemic for hepatitis A, Dr. Chaves noted.

By statistical estimation, the risk of hepatitis A infection is approximately 106 per 100,000 close contacts of international adoptees in the United States, compared with the actual annual incidence of 1.2/100,000 in 2006 in the general population, Dr. Chaves said.