Author(s): Mary Allen Staat, Jennifer (Jenna) Beeler, Emily Jentes

Since 1999, >275,000 children have come to the United States to join families through international adoption. Children being adopted from other countries can have infectious (and environmental) diseases due to exposure to pathogens endemic to their birth country; they also might be underimmunized or unimmunized, have lacked access to clean water, lived in crowded or possibly unsanitary conditions, and be malnourished. Families traveling to unite with their adopted child, siblings who wait at home for the child’s arrival, extended family members, and childcare providers are all at risk of acquiring infectious diseases secondary to travel or from contact with their new family member. Clinicians can play an important role in helping families prepare to travel and welcome adoptees safely.

Preparing Adoptive Parents & Families

Prospective adoptive parents should schedule a pretravel visit with a travel health clinic. To best prepare adoptive parents and families going to meet their new child, travel health providers should be aware of disease risks in the adopted child’s country of origin, the medical and social history of the adoptee (if available), the medical and vaccination histories of family members traveling to meet the child, the season of travel, the length of stay in the country, and the itinerary. Provide prospective adoptive parents and any family members traveling with them with needed vaccinations, malaria prophylaxis, diarrhea prevention and treatment, advice on coronavirus disease 2019 (COVID-19) prevention measures and travel requirements, general advice on travel and food safety, and other travel-related health issues, as outlined elsewhere in the Centers for Disease Control and Prevention (CDC) Yellow Book.

Vaccinations

All family members should be up to date with all routine immunizations; this includes those who travel to meet the adopted child, those who remain at home, and all extended family members. Provided minimum age and dose intervals are followed, an accelerated dose schedule can be used to complete a vaccine series, if necessary.

Ensure all age-eligible people who will be in the household or in close contact with the adopted child (e.g., caregivers) are protected against diphtheria, hepatitis A virus (HAV), measles, pertussis, polio, tetanus, and varicella; include hepatitis B virus (HBV) vaccine if the adoptee has known infection or if the family is traveling to a country with high or intermediate levels of endemic HBV infection (see Sec. 5, Part 2, Ch. 8, Hepatitis B). Make sure all eligible family members are up to date with their COVID-19 vaccines.

Hepatitis

Before the adopted child’s arrival, immunize unprotected family members and close contacts against HAV. Because hepatitis B vaccine has only been routinely given since 1991, some adult family members and caretakers might need to be immunized if the adoptee has a known HBV infection.

Measles

Measles immunity or 2 doses of measles-mumps-rubella (MMR) vaccine separated by ≥28 days should be documented for all people born in or after 1957.

Polio

If the adopted child is from a polio-endemic area (see CDC Travelers’ Health travel health notices), ensure family members and caretakers have completed the recommended age-appropriate polio vaccine series. A one-time inactivated polio vaccine (IPV) booster for adults who completed the primary series in the past is recommended if they are traveling to polio-endemic areas; vaccination also can be considered for adults who remain at home but who will be in close contact caring for the child. Additional polio vaccine requirements for residents and long-term travelers (staying >4 weeks) departing from countries with polio transmission could affect outbound travel plans (see Sec. 5, Part 2, Ch. 17, Poliomyelitis).

Tetanus-Diphtheria-Pertussis

Adults who have not received the tetanus-diphtheria-acellular pertussis (Tdap) vaccine, including adults >65 years old, should receive a single dose to protect against diphtheria, pertussis, and tetanus.

Varicella

Administer varicella vaccine to people born in or after 1980 without a history of varicella disease, documented immunity (serology), or documentation of 2 doses of varicella vaccine.

Overseas Medical Examination

All immigrants, including children adopted internationally by US citizens, must undergo a medical examination in their country of origin, performed by a physician designated by the US Department of State. See additional information about the medical examination for internationally adopted children and vaccination affidavit [PDF].

The explicit purpose of the overseas medical examination is to identify applicants with inadmissible health-related conditions. Prospective adoptive parents should not rely on this evaluation to detect all disabilities and illnesses a child might have. To understand more about possible health concerns for an individual child, prospective adoptive parents should consider a preadoption medical review with a pediatrician familiar with the health issues of internationally adopted children. That provider can review the available medical history and vaccination records for the child, thereby preparing parents for any potential health issues that might exist.

Prospective adoptive parents can then proactively schedule any recommended follow-up, including an initial medical examination that is recommended within 2 weeks of arrival to the United States. Adoptive parents might receive a copy of the overseas examination, recorded on US Department of State medical forms, to give to clinicians at the initial follow-up medical examination.

Follow-Up Medical Examination

Providing health care to internationally adopted children can be challenging for several reasons (see Box 7-05). Adopted children should have a complete medical examination ≤2 weeks after their US arrival—earlier than that if they have anorexia, diarrhea, fever, vomiting, or other apparent health issues. In addition, a developmental screening examination conducted by an experienced clinician can help identify if immediate referrals should be made for a more detailed neurodevelopmental assessment and therapies. Clinicians might recommend further evaluation based on the age of the child, their country of origin, developmental status, nutritional status, previous living conditions, and the adoptive family’s specific questions. Concerns raised during the preadoption medical review could dictate further investigation.

Infectious Diseases Screening

Screening recommendations for infectious diseases vary by organization. See Table 7-01 for the current panel of infectious disease screening tests recommended by the American Academy of Pediatrics (AAP) for internationally adopted children.

Eosinophilia

All internationally adopted children should have a complete blood count with differential. An eosinophil count >450 cells/mL warrants further evaluation; intestinal parasite screening can identify some helminth infections. Investigation of eosinophilia also should include serologic evaluation for Strongyloides stercoralis and Toxocara canis; both are found worldwide. Perform serologic testing for filariasis and Schistosoma spp. in children arriving from endemic countries.

Hepatitis A

Screening asymptomatic people for hepatitis A is generally not recommended; clinicians might, however, decide to test internationally adopted children for HAV IgG and IgM to identify those who are acutely infected and shedding virus. Vaccinate adopted children against HAV if they are not already immune.

In 2007 and early 2008, multiple cases of hepatitis A were reported in the United States secondary to exposure to newly arrived internationally adopted children. Some of these cases involved extended family members not living in the household. Identification of acutely infected toddlers new to the United States could prevent further transmission. If an acute infection is found in a child, close contacts can receive hepatitis A vaccine or immunoglobulin to prevent infection. In addition, serologic testing is a cost-effective way to identify children with past infection.

Hepatitis B

With the widespread use of the hepatitis B vaccine, the prevalence of HBV infection has decreased overall, and lower rates of infection (1%–5%) have been reported in newly arrived international adoptees. In recent years, most children with HBV infection were known to be infected prior to adoption.

All internationally adopted children should be screened for HBV infection with serologic tests for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody, and hepatitis B core antibody to determine past infection, current infection, or protection due to prior vaccination. For children positive for HBsAg, retest 6 months later to determine if they have chronic infection. Report results of a positive HBsAg test to the state health department.

HBV is highly transmissible within households; for this reason, all members of households adopting children with chronic HBV infection should be immunized. Children with chronic HBV infection should receive additional tests for hepatitis e antigen (HBeAg), hepatitis B e antibody (anti-HBe), HBV viral load, hepatitis D virus antibody, and liver function, and should have a consultation with a pediatric gastroenterologist for long-term management.

Although not currently recommended by the CDC or the AAP, consider repeat screening 6 months after arrival for all children who initially test negative for hepatitis B surface antibody and surface antigen.

Hepatitis C

The prevalence of hepatitis C in internationally adopted children is low. Most children with hepatitis C virus (HCV) infection are asymptomatic, and screening for risk factors (e.g., having an HCV-positive mother, surgery in the child’s birth country, a history of transfusions, major dental work, intravenous drug use, tattoos, sexual activity or abuse, female genital cutting, traditional cutting) generally is not possible. But because effective treatments are available and infected patients need close follow-up to identify long-term complications, consider routine screening for HCV.

Use antibody testing (IgG ELISA) to screen children ≥18 months of age; use PCR testing for younger children. Refer children with HCV infection to a gastroenterologist for further evaluation, management, and treatment.

HIV

HIV screening is recommended for all internationally adopted children. HIV antibodies found in children aged <18 months could reflect maternal antibodies rather than infection of the infant. An HIV-1/HIV-2 antigen/antibody combination assay is used for standard screening, but some experts recommend PCR for any infant aged <6 months on arrival to the United States. A PCR assay for HIV DNA can confirm the diagnosis in an infant or child. If PCR testing is done, 2 negative results from assays administered 1 month apart, at least 1 of which is done after the age of 4 months, are necessary to exclude infection. Some experts recommend repeating screening for HIV antibodies 6 months after arrival if the initial test results are negative. Refer children with HIV infection to a specialist.

Intestinal Pathogens

Children treated for intestinal pathogens who have persistent growth delay, or who have ongoing or recurrent symptoms or unexplained anemia, merit a more extensive work-up. Notify public health authorities of reportable infections, and forward isolates for surveillance as appropriate.

Parasitic

Gastrointestinal parasites commonly are seen in international adoptees, but prevalence varies by age and birth country. As children become older, the risk for parasitic infection and detection increases. The presence or absence of symptoms is not predictive of intestinal parasites; thus, screening is needed. In both past and more recent studies, the highest rates of parasite detection are reported among children adopted from Ukraine and from African, Latin American, and Asian countries, as compared to children coming from Russia and other countries in Eastern Europe. Unlike refugees, internationally adopted children are not treated for parasites before departure, and some clinicians opt to treat newly arrived adoptees with a single dose of albendazole.

Three stool samples collected in the early morning, 2–3 days apart, and placed in a container with preservative provides the highest yield for ova and parasite (O&P) detection. In addition, because routine O&P analysis is unlikely to include testing for either Cryptosporidium or Giardia, order the combined antigen test for these 2 parasites. Giardia duodenalis is the parasite most often identified.

Bacterial

Conduct additional stool testing for children with fever and diarrhea, especially acute-onset bloody diarrhea. Non-culture methods (e.g., gastrointestinal pathogen panels with PCR) commonly are used. If a bacterial pathogen is identified by a non-culture method, collect and culture samples to determine antimicrobial susceptibility and inform treatment decisions; bacterial pathogens can be resistant to antibiotics.

Malaria

Routine malaria screening is not recommended for internationally adopted children. Instead, obtain thick and thin malaria smears immediately for any child coming from a malaria-endemic area who presents with fever or who has symptomatic splenomegaly (i.e., splenic enlargement plus fever or chills). Rapid diagnostic tests (RDTs) for malaria can help expedite the diagnosis, but microscopy is still required to confirm the results and to determine the degree of parasitemia (see Sec. 5, Part 3, Ch. 16, Malaria). PCR testing can confirm the species of parasite after the diagnosis has been established by either smear microscopy or RDT.

Further evaluation also is warranted in asymptomatic children with splenomegaly who come from areas endemic for malaria, as they could be exhibiting hyperreactive malaria splenomegaly. This evaluation should include antibody titers for malaria, since asymptomatic children with splenomegaly caused by repeated malaria infections can have high titers but negative smears.

Sexually Transmitted Infections

Chlamydia & Gonorrhea

Although screening for sexually transmitted infections other than HIV and syphilis is not routinely recommended, some experts will screen all children >5 years of age for chlamydia and gonorrhea. Regardless of age, if questions or concerns of sexual abuse are present, or if HIV or syphilis are diagnosed in the child, perform chlamydia and gonorrhea screening.

Syphilis

Screening for Treponema pallidum is recommended for all internationally adopted children. Initial screening is done with both nontreponemal and treponemal tests. Treponemal tests remain positive for life in most cases, even after successful treatment, and are specific for treponemal diseases, including syphilis and other diseases (e.g., bejel, pinta, yaws) found in some countries.

In children with a history of syphilis, documentation is rarely available for the initial evaluation (serology and lumbar puncture results with cell count, protein, VDRL), treatment (antibiotic used, dose, frequency, and duration), and follow-up serologic testing; therefore, conduct a full evaluation for disease, and provide treponemal treatment depending on the results.

Trypanosomiasis / Chagas Disease

Chagas disease is endemic to much of Mexico and throughout countries in Central and South America (see Sec. 5, Part 3, Ch. 25, American Trypanosomiasis / Chagas Disease). Infection risk varies by region within endemic countries. Although the risk for Trypanosoma cruzi infection is likely low in children adopted from endemic areas, consider screening.

Serologic testing when the child is aged 9–12 months will avoid possible false-positive results from maternal antibodies. PCR testing can be done for children <9 months of age. Refer children who test positive for Chagas disease to a specialist for further evaluation and management; treatment is effective.

Tuberculosis

Internationally adopted children have 4–6 times the risk for tuberculosis (TB) compared to their US-born peers. TB screening is an integral part of the pretravel overseas medical examination; check with adoptive parents or with the local health department for screening results. If results are not immediately available, screen all internationally adopted children for TB after they arrive in the United States; report any positive cases to the state health department.

Screening for TB after US arrival is important because TB can be more severe in young children and can reactivate when the child gets older. To screen, AAP recommends a tuberculin skin test (TST) for children <2 years of age. For children ≥2 years of age, use either a TST or an interferon-γ release assay (IGRA). For children previously vaccinated with bacillus Calmette-Guérin (BCG), IGRAs appear to be more specific than the TST for Mycobacterium tuberculosis infection (see Sec. 5, Part 1, Ch. 23, . . . perspectives: Testing Travelers for Mycobacterium tuberculosis Infection). On arrival to the United States, some children might be anergic (i.e., have a false negative TB screen) due to malnutrition, stress, or untreated HIV infection, or they might have been infected just prior to travel. Thus, if the initial screen is negative, repeat testing 3–6 months after arrival.

If the TST or IGRA is positive, the child has TB infection, which requires additional evaluation to determine whether the child has TB disease. If a child has evidence of TB disease, consult with an infectious disease expert.

Vaccinations

The US Immigration and Nationality Act requires everyone seeking an immigrant visa for permanent residency to show proof of having received Advisory Committee on Immunization Practices (ACIP)-recommended vaccines before immigration. This requirement extends to all immigrant infants and children entering the United States. Although internationally adopted children aged <10 years are exempt from the overseas immunization requirements, CDC encourages vaccination prior to travel to the United States. If an adopted child <10 years old is not vaccinated as part of their pretravel overseas medical examination, the adoptive parents must sign an affidavit indicating their intention to comply with the immunization requirements within 30 days of the child’s arrival to the United States. See vaccination affidavit [PDF].

Vaccination Records

Vaccination record reliability differs by, and even within, country of origin. Some children might have full documentation of vaccines received and dates given, while others have incomplete or no records. MMR is not given in most countries of origin because measles vaccine often is administered as a single antigen. In addition, some children might be immune to hepatitis A, measles, mumps, rubella, or varicella because of natural infection. A clinical diagnosis of any of these diseases, however, should not be accepted as evidence of immunity.

Catch-Up Vaccinations

Most international adoptees arrive to the United States already having been vaccinated against diphtheria, hepatitis B, measles, pertussis, polio, tetanus, and tuberculosis (with BCG) in their country of birth. Because Haemophilus influenzae type b (Hib), hepatitis A, human papillomavirus, meningococcal, mumps, pneumococcal conjugate, rotavirus, rubella, and varicella vaccines are not given routinely in low- and middle-income countries, however, >90% of newly arrived internationally adopted children need catch-up vaccines to meet ACIP guidelines.

Vaccination Plan

Providers can choose 1 of 2 approaches for developing a vaccination plan for internationally adopted children. The first approach is to revaccinate regardless of the child’s vaccination record from their birth country. The second approach, applicable to children ≥6 months of age, is to perform antibody testing and to revaccinate accordingly. One exception to this second approach is pertussis; Bordetella pertussis antibody titers do not correlate with immune status, although higher protective antibody levels for diphtheria and tetanus could be extrapolated to mean that a child has protection against pertussis, as well.

Hepatitis B is another exception. Anti-HBs as a correlate of vaccine-induced protection has only been determined for people who have completed an approved vaccination series. To be considered immune, ACIP recommends that children with positive hepatitis B surface antibody have documentation of 3 appropriately spaced doses of hepatitis B vaccine. For children with positive hepatitis B surface antibody and positive hepatitis B core antibody, vaccination is not required, as they are considered immune after natural infection.

For children ≥6 months of age, perform testing for diphtheria (IgG), hepatitis B (as outlined above), Hib, and tetanus (IgG). For children ≥12 months of age, also perform testing for hepatitis A, measles, mumps, rubella, and varicella. Since April 2016, many resource-poor countries have used bivalent oral polio vaccine; for children born on or after this date who do not have documentation of receiving IPV according to an approved (US or World Health Organization) schedule, administer the age-appropriate vaccine series. Revaccination with pneumococcal vaccine is recommended because the vaccine has 13 serotypes, and antibody testing would not be cost-effective.

Once the vaccination record has been assessed and antibody level results are available, give any indicated vaccines according to the current ACIP catch-up schedule. If an adopted child is <6 months old and uncertainty remains regarding their vaccination status or the validity of the vaccination record, administer vaccines according to the ACIP schedule.

Noninfectious Disease Screening

Several screening tests for noninfectious diseases should be performed in all or in select internationally adopted children. All children should have a complete blood count with a differential (as previously noted), hemoglobin electrophoresis, and glucose-6-phosphate-dehydrogenase (G6PD) deficiency screening. Measure serum levels of thyroid-stimulating hormone, and obtain a blood lead level in all internationally adopted children. Consider testing for serum levels of iron, iron-binding capacity, transferrin, ferritin, and total vitamin D 25-hydroxy. Perform vision and hearing screening and a dental evaluation on all children. Consider neurologic and psychological testing if the child’s clinical presentation raises concern.