A Letter to Parents Adopting Internationally
The Importance of Testing and Immunizing for Hepatitis B Amongst Internationally Adopted Children from Asia and Their Families
Chronic Hepatitis B infection is common in Asian countries. While in their birth country, all Asian children to be adopted internationally are tested for Hepatitis B. This is done because the countries’ adoption agencies will not knowingly refer a child who has active Hepatitis B unless the parents have asked for this special needs referral. However, testing for Hepatitis B is complicated, particularly when the Hepatitis B status of the birth mother isn’t known. As parent(s), you need to be aware of the following:
- Hepatitis B acquired at birth cannot be definitely ruled out until the child is more than 6 months of age as it may take up to 6 months for the confirmatory test (HBsAg) to become positive. Most of the referral medicals from China are done after 6 months of age but the younger the child, the more likely that the medical will have been done before 6 months of age (ie before congenital Hepatitis B can be ruled out). Korean medicals are generally done before 6 months of age.
- Hepatitis B immunization is becoming more routine amongst the referring orphanages in China, and is routine in Korea, although in China, it may not always be done early enough to prevent congenital infection. In addition, as with the other immunizations performed overseas on internationally adopted infants, it cannot be assumed that the Hepatitis B vaccines were given appropriately and therefore will have the usual effectiveness rate. Tests must be done after arrival in Canada to confirm that the Hepatitis B immunization was effective (ie, positive antibodies known as anti-HBs).
- Unless the baby is more than 18 months of age at the time of testing, it is impossible to distinguish the antibodies acquired through successful Hepatitis B immunization, from what are known as maternal antibodies. If the birth mother was immunized against Hepatitis B or was previously infected with Hepatitis B and has successfully cleared the virus, the baby can carry these maternal antibodies against Hepatitis B (also known as anti-HBs) until 12-18 months of age. It is therefore important to test for this again after 18 months of age.
- There is no test that can be done prior to adoption which will definitely rule out active Hepatitis B. This is because the tests which are used to diagnose Hepatitis B may not become positive until 4-12 weeks after exposure (e.g. from infected needles).
- Most children with active Hepatitis B have no symptoms. Only blood tests can rule out Hepatitis B infection.
- To our knowledge, only a very mall number of children adopted internationally from Asia have active Hepatitis B (estimates range from <1% to 5%). However, this is a very serious infection with potential long-term medical and social implications.
In view of these facts, we strongly recommend the following for all Children’s Bridge families:
- All immediate family members should be immunized against Hepatitis B even if they aren’t traveling. This is to protect family members from being infected by a child who is diagnosed with Hepatitis B after return to Canada although this is a very rare situation, as is household transmission.
- Written documentation that Hepatitis B immunization was performed in Asia cannot be accepted as indicating the child is immune. Furthermore, if the immunization wasn’t effective, the child could have contracted Hepatitis B (although this too is very rare).
- All children adopted from Asia should be tested for Hepatitis B (and C) upon arrival in Canada. Repeat testing must be done in 6 months or after 18 months of age (whichever is later) to definitely rule out Hepatitis B infection or confirm immunity.
- Finally, all children adopted internationally should be immunized against Hepatitis B. The only exception should be those who already have or have had active Hepatitis B. The age groups at highest risk for contracting and transmitting Hepatitis B are infants/preschool children and sexually active adolescents/adults. Some Canadian provinces don’t cover the cost of Hepatitis B immunization until later childhood. However, in those provinces, it may be possible to get the costs covered if there is a family member at risk (e.g. future sibling to be adopted internationally).
If you have questions regarding your child’s Hepatitis B results, the testing required, and immunization status, we recommend you talk to your doctor. You may want to bring this letter with you to your doctor’s appointment to help with the discussion.
Margaret Lawson, MD, FRCPC (Children’s Bridge Groups 75 and 122)
Associate Professor, Pediatrics
Children’s Hospital of Eastern Ontario
Volunteer Medical Consultant, The Children’s Bridge