Follow-up Medical Examinations after Arrival in the United States
The varied geographic origins of internationally adopted infants and children, their unknown backgrounds before adoption (including parental history and living circumstances), and the inadequacy of health care in many developing countries make appropriate medical evaluation of internationally adopted children a complex and important task. This evaluation should be performed within 2 weeks of the child’s arrival in the United States. The content of the medical evaluation should be guided by the unique circumstances and needs of the child, taking into account the child’s region and country of birth, past living conditions, and travel and medical history. In addition to the screening for infectious disease described below, a full medical and developmental assessment should be done, with attention to possible malnutrition, conditions undetected by limited prior care, and ectoparasites such as scabies and lice, in addition to other indicated tests, such as lead (5) or G6PD.
SCREENING FOR INFECTIOUS DISEASES
Infectious diseases, among the most common medical diagnoses, have been found in up to 60% of internationally adopted children, depending on their country of origin; many of these infections can be asymptomatic (6-10). Screening for these diseases is important for the health of the adopted infant or child as well as that of their adoptive family. The American Academy of Pediatrics (AAP) recommends that all internationally adopted children be screened with the following: hepatitis B serology, HIV serology, syphilis serology, Mantoux intradermal skin test for tuberculosis, stool examination for ova and parasites, and complete blood count including a peripheral eosinophil count and red blood cell indices (11). Regardless of eosinophil count, all international adoptees should have three separate stool samples, collected on 3 separate days, analyzed for ova and parasites. HIV antibodies in a child younger than 18 months of age may reflect maternal infection without transmission to the infant, and infection in the infant should be confirmed with an assay for HIV DNA by polymerase chain reaction. Two negative tests obtained 1 month apart are required for the child to be considered uninfected.
Tuberculin skin tests measuring less than 5 mm are negative; reactions larger than 5 mm are interpreted based on risk factors for diseases. For internationally adopted children born in regions of the world with high TB prevalence, a reaction of 10 mm or more of induration is always positive; a reaction from 5 to 9 mm is positive if the child is immunocompromised, has been exposed to tuberculosis, or has signs or symptoms of TB disease. If the TST is positive, a chest radiograph should be performed to evaluate for active TB disease. If evidence of TB disease is found, efforts to isolate an organism for sensitivity testing are very important because of the high proportions of drug resistance in many other countries, including countries in Eastern Europe, the former Soviet Union, and Asia. Some experts also recommend that health-care providers consider repeating the TST (if negative) 2-3 months after arrival when nutritional status has been improved, particularly if the child had evidence of under- or malnutrition at the initial screening (10). Receipt of BCG vaccine is not a contraindication for TST. Because BCG does not prevent infection with TB and because of the high risk for exposure in most countries where BCG is given, the AAP recommends that children with a positive TST be given 9 months of isoniazid therapy (11).
Up to 35% of internationally adopted children have ova or parasites identified on stool examinations (6-10). For Giardia intestinalis and Cryptosporium parvum infection, stool examination for antigen by enzyme immunoassay may be more sensitive than microscopic exam. Giardiasis is particularly prevalent in internationally adopted children from Eastern Europe. Strongyloides stercoralis serologic testing, available at CDC on request through the state public health laboratory, should be considered for children who have a high eosinophil count. If enteric symptoms develop in the future, tests should be repeated, even if it has been several years after arrival in the United States.
Other screening tests may be recommended based on country of origin, risk factors, symptoms, or clinical findings. For example, children from schistosomiasis-endemic areas (see Map 4-11) should have serologic tests for schistosomiasis performed at CDC, which may be requested through the state public health laboratory (http://www.dpd.cdc.gov/dpdx/HTML/DiagnosticProcedures.htm). Screening for hepatitis C should be considered for all infants and children adopted from Asia, Eastern Europe, or Africa. Hepatitis C testing for children adopted from other areas should be considered if the records indicate potential risk factors, such as receipt of blood products or maternal drug use. Testing for hepatitis D, which is available at CDC, should be considered for children from the Mediterranean area, Africa, Eastern Europe, and Latin America who have chronic infection with hepatitis B virus.
Laboratory reports from the country of origin should not necessarily be considered reliable.
VACCINATION
Internationally adopted infants and children frequently are underimmunized and should receive necessary immunizations according to the ACIP-recommended schedules in the United States (see Tables 8-2—8-4) (12,13). In a retrospective review of records of 504 children, the majority (65%) had no written records of overseas vaccination. Among the 178 children with documented overseas vaccination, 167 (94%) had valid records and some vaccine doses that were acceptable and up to date under the U.S. schedule (14).
In assessing the immunization status of an internationally adopted child, only written documentation should be accepted as proof of receipt of immunization. In general, written records are deemed valid if the vaccine type, date of administration, number of doses, intervals between doses, and age of the patient at the time of administration are comparable with the current U.S. schedule. Although some vaccines with inadequate potency have been produced in other countries, most vaccines used worldwide are produced with adequate quality control standards and are reliable (11,13). However, immunization records for some internationally adopted children, particularly those from orphanages, may not reflect protection because of inaccurate or unreliable records, lack of vaccine potency, poor nutritional status, or other problems (2-4, 14). For any child, if there is any question as to whether the immunizations were administered or were immunogenic, the best course is to repeat them. Vaccination is generally safe and avoids the need to obtain and interpret serologic tests.
In an older infant or child who is thought to have been vaccinated appropriately, judicious use of serologic testing can be helpful in determining which immunizations may be needed and can decrease the number of injections required (10,11). Children who do not have serologic evidence of previous hepatitis B infection should receive the full vaccine series. Many adopted children acquire hepatitis A virus infection early in life and are immune thereafter. Thus, in the United States it may be cost effective to screen these children for previous immunity before initiating the vaccination series. Verification of protection from MMR vaccine requires testing for antibodies to each virus. Serology is of limited availability or difficult to interpret for Haemophilus influenzae type b (Hib) and poliovirus. Vaccination for these, as well as varicella and pneumococcal disease, which are not administered in most countries, should be administered to internationally adopted children based on age and medical history.
Data indicate increased risk of local adverse reactions after the fourth and fifth doses of DTP or DTaP. In some circumstances, judicious use of serologic testing of antibody levels to assess immunity may be helpful in decreasing the possibility of vaccine side effects. For children whose records indicate that they have received more than 3 doses, options include initial serologic testing or administration of a single booster dose of DTaP, followed by serologic testing after 1 month. If a severe local reaction occurs after revaccination, serologic testing for specific IgG antibody to tetanus and diphtheria toxins can be measured before additional doses are administered. No established serologic correlates exist for protection against pertussis, but protective concentrations of antibody to both diphtheria and tetanus toxin can serve to validate the vaccination record.
