International Adoption

Introduction

Every year, more than 1,000 children come to the United States to join families through international adoption. Children being adopted can be exposed to environmental agents or infectious diseases that are endemic in their birth countries. Living conditions in the birth country, including crowding, nutritional deficiencies, and lack of access to clean water, health services, and vaccinations, can increase the risk of infectious diseases.

Families traveling to unite with their adopted children, siblings who wait at home for the children'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 members. Clinicians can play an important role in helping families prepare to travel and welcome adoptees safely.

Preparing adoptive parents and families

To understand the health risks for the adopted child and their family, prospective adoptive parents planning to travel internationally should schedule a pre-travel visit with a travel medicine clinic. To best prepare adoptive parents and families, travel medicine specialists 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. Travel medicine specialists should provide prospective adoptive parents and any family members traveling with them with needed vaccinations, malaria prophylaxis, travelers' diarrhea precautions and treatment, and 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 (see The Pre-Travel Consultation chapter).

Vaccinations

All family members should be up to date with routine immunizations; this includes those who travel to meet the adopted child, those who remain at home, and extended family members. A catch-up immunization schedule can be implemented (using intervals between doses that are shorter than intervals recommended for routine vaccination) to complete a vaccine series, if necessary, provided minimum age and dose intervals are followed. 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 COVID-19, diphtheria, hepatitis A virus (HAV), hepatitis B virus (HBV), measles, pertussis, tetanus, polio, and varicella.

Coronavirus disease 2019

All eligible family members should be up to date with COVID-19 vaccination (see COVID-19 chapter).

Viral hepatitis

Hepatitis A

Before the adopted child's arrival, immunize all persons who are not fully vaccinated and who anticipate close personal contact (e.g., household contact or regular babysitting) with international adoptees within the first 60 days after arrival from countries of intermediate or high endemicity (see Hepatitis A chapter). The first dose of the 2-dose hepatitis A vaccine series should be administered as soon as adoption is planned, ideally 2 or more weeks before travel or the arrival of the adoptee.

Hepatitis B

Because hepatitis B vaccine has only been given to children routinely since 1991 and recommended for all adults younger than 60 years and adults 60 years and older at increased risk since 2022, some adult family members and caretakers might need to be immunized. Getting family members and caregivers up to date on hepatitis B vaccination is especially important if the adoptee has known HBV infection or if the family is traveling to a country with intermediate or high levels of endemic HBV.

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 (see Measles (Rubeola) chapter).

Tetanus-diphtheria-pertussis

Adults who did not receive the tetanus-diphtheria-acellular pertussis (Tdap) vaccine at or after 11 years, including adults ≥65 years, should receive a single dose to protect against diphtheria, pertussis, and tetanus and then tetanus-diphtheria (Td) or Tdap every 10 years. Adults who did not receive the primary vaccination series for tetanus, diphtheria, or pertussis should receive additional doses (see Advisory Committee on Immunization Practices, ACIP, vaccination notes). Children should receive vaccinations according to the ACIP Child and Adolescent Immunization Schedule.

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 while 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 Poliomyelitis chapter).

Varicella

Varicella immunity or 2 doses of varicella separated by 4–8 weeks should be documented for all people born in or after 1980. Children 12 months and older can receive varicella vaccination according to the routine child immunization schedule, or dose 2 may be administered as early as 3 months after dose 1 (a dose inadvertently administered after at least 4 weeks may be counted as valid).

Overseas medical examination

All immigrants, including children adopted internationally by U.S. citizens, must undergo a medical examination in their country of origin, performed by a physician designated by the U.S. Department of State. The purpose of the overseas medical examination is to identify applicants with certain medical conditions, known as Class A conditions, that make a person inadmissible to the United States. These include communicable diseases of public health significance. See additional information about the medical examination for internationally adopted children on CDC's and Department of State's websites. Adoptive parents can request a copy of the overseas examination, recorded on U.S. Department of State medical forms, to give to the child's clinicians in the United States.

Prospective adoptive parents should not rely on this medical examination to detect all the child's health concerns. 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 and prepare parents for any potential health issues. Prospective adoptive parents can then schedule an initial medical examination that is recommended after arrival to the United States, during which follow-up for potential health concerns can be done.

Post-arrival medical examination

Adopted children should have a complete medical examination within a few weeks after United States arrival, or earlier if they have anorexia, diarrhea, fever, vomiting, or other apparent health issues. A developmental screening examination conducted by an experienced clinician can help determine whether an immediate referral should be made for a more detailed neurodevelopmental assessment or therapy. Clinicians may recommend further evaluation based on the age of the child, their country of origin, developmental status, nutritional status, previous living conditions, the adoptive family's specific questions, or concerns raised during the preadoption medical review. Providers should be aware that providing health care to internationally adopted children can be challenging for several reasons (Box 9.5.1).

Box 9.5.1

Laboratory testing

Complete blood count

All internationally adopted children should have a complete blood count (CBC) with red blood cell indices, and white blood cell differential. These tests may indicate common underlying conditions, including iron deficiency and inherited anemias. Additionally, these tests may reveal rare conditions or parasitic infections that may result in morbidity or mortality if not treated. Based on the results of these tests, additional, more focused laboratory testing may be warranted.

Infectious diseases screening

Screening recommendations for infectious diseases vary by organization. See Table 9.5.1 for the current panel of infectious disease screening tests recommended by the American Academy of Pediatrics (AAP) for internationally adopted children.

Table 9.5.1: American Academy of Pediatrics (Red Book) recommended infectious disease screening for international adoptees¹

Viral hepatitis

Hepatitis A

Clinicians may consider testing internationally adopted children for anti-HAV IgM to identify those who are acutely infected and shedding virus. In 2007 and 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. If an acute infection is found in a child, close contacts can receive hepatitis A vaccine or immunoglobulin to prevent infection (see Hepatitis A chapter). Testing for anti-HAV IgG is a cost-effective way to identify children with past infection; presence of anti-HAV IgG indicates immunity either from prior infection or vaccination. Vaccinate adopted children against HAV if they are not already immune.

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, including hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and antibody to hepatitis B core (anti-HBc) to determine past infection, current infection, or protection due to prior vaccination. HBsAg can indicate acute infection; IgM anti-HBc positivity can also indicate acute (within less than 6 months) infection and should be ordered only when acute HBV infection is a concern. Although not currently recommended by the CDC or the AAP, consider repeat screening 6 months after arrival (i.e., in a primary care setting) for all internationally adopted children who initially test negative for anti-HBs and HBsAg overseas.

Children with known chronic HBV infection or newly discovered positive HBsAg or IgM anti-HBc test results should receive further testing (e.g., hepatitis e antigen (HBeAg), hepatitis B e antibody (anti-HBe), HBV viral load, hepatitis D virus antibody, and liver function) and be referred to a gastroenterologist or infectious disease specialist for further evaluation and treatment to reduce their risk of complications from chronic HBV infection and to reduce risk of transmission. Report results of a positive HBsAg or IgM anti-HBc test to the state health department.

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. 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 or infectious disease specialist for further evaluation, management, and treatment.

Sexually transmitted infections

Chlamydia and gonorrhea

Although screening for sexually transmitted infections other than human immunodeficiency virus (HIV) and syphilis is not routinely recommended, some experts will screen all internationally adopted 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 with urine PCRs.

Syphilis

Screening for Treponema pallidum is recommended for all internationally adopted children. Initial screening can be done with either a nontreponemal test ("conventional approach") or a treponemal test ("reverse sequence screening"), with subsequent testing depending on the screening test result. Treponemal tests are specific for treponemal diseases, including syphilis and other diseases (e.g., bejel, pinta, yaws) found in some countries. In most cases, reactive (positive) treponemal tests will remain reactive, even after successful treatment. Treponemal antibody titers do not predict treatment response and therefore should not be used for this purpose. Nontreponemal test antibody titers may correlate with disease activity and are used for monitoring treatment response.

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.

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; therefore, children <18 months of age should be tested with a nucleic acid test. A PCR assay for HIV DNA or RNA 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. Children aged ≥18 months should be tested with an HIV antigen/antibody assay. 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 an infectious disease specialist for further evaluation and treatment.

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.

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 to inform treatment decisions; bacterial pathogens can be resistant to antibiotics (see Post-Travel Diarrhea chapter).

Parasitic

Gastrointestinal parasites are commonly seen in international adoptees, but prevalence varies by age and birth country. As children become older, the risk for parasitic infection 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, compared to children coming from Russia and other countries in Eastern Europe. Three stool samples, collected 2–3 days apart and placed in a container with preservative, provide the highest yield for ova and parasite detection. A single specimen is sufficient for Cryptosporidium and Giardia using the combined antigen test for these 2 parasites. Giardia duodenalis is the parasite most often identified. Unlike refugees, internationally adopted children are not treated for parasites before departure, and some clinicians opt to treat newly arrived adoptees (12 months of age or older) with a single dose of albendazole (see Post-Travel Parasitic Disease Including Evaluation of Eosinophilia chapter).

Eosinophilia

A CBC with a differential can be used to identify eosinophilia (see Post-Travel Parasitic Disease Including Evaluation of Eosinophilia chapter). An eosinophil count >450 cells/mL warrants further evaluation; persistent eosinophilia can be due to parasitic infection. Investigation of eosinophilia should include serologic evaluation for Strongyloides stercoralis and Toxocara canis; both are found worldwide. Serologic testing for schistosomiasis may be indicated for children with eosinophilia who have recently arrived from endemic countries. Evaluation for lymphatic filariasis should be considered in children from endemic regions.

Malaria

Routine malaria screening is not recommended for internationally adopted children. Evaluation is warranted if a child is from a country where the disease is endemic and has signs or symptoms of malaria, including unexplained fever, splenomegaly, or anemia. Obtain thick and thin malaria smears. Rapid diagnostic tests (RDTs) for malaria can help expedite the diagnosis, but microscopy is still necessary to confirm the results and to determine the degree of parasitemia (see Malaria chapter). PCR testing can confirm the species of parasite after the diagnosis has been established by either smear microscopy or RDT.

Further evaluation is warranted in asymptomatic children with splenomegaly who come from areas endemic for malaria because 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.

American trypanosomiasis/Chagas disease

Chagas disease is endemic to much of Mexico and countries in Central and South America. Infection risk varies by region within endemic countries. Although the risk for Trypanosoma cruzi infection is often unknown in children adopted from endemic areas, consider screening.

Serologic testing should be performed when the child is aged at least 9–12 months, after maternal antibodies would have resolved. Refer children who test positive for Trypanosoma cruzi infection to a specialist for further evaluation and management; treatment is effective.

Tuberculosis

Children who were born and lived in or have traveled to an area of the world with a high prevalence of tuberculosis (TB) are at higher risk for TB infection than the general population. Screening for tuberculosis (TB) is an integral part of the pre-travel overseas medical examination for children examined in countries with high TB burden; adoptive parents or the local health department will have TB screening results. If results are not immediately available, screen all internationally adopted children for TB after they arrive in the United States. Cases of TB disease should be reported to the state health department.

Screening internationally adopted children for TB infection after U.S. arrival is important because TB disease can be severe in young children and risk of reactivation of latent TB infection is high in young children. To screen for TB infection in asymptomatic children, the AAP recommends either a tuberculin skin test (TST) or interferon-gamma release assay (IGRA). The CDC's immigrant and refugee screening recommendations differ from AAP's and recommend a TST for children <2 years and an IGRA for children ≥2 years. For children previously vaccinated with bacillus Calmette-Guérin (BCG), IGRAs appear to be more specific than the TST for Mycobacterium tuberculosis infection (see Tuberculosis chapter). During overseas screening, 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 may have TB infection, and additional evaluation to determine whether the child has active or latent TB disease is required. Consult with an infectious disease expert for recommendations on further evaluation and treatment for children with positive test results.

Vaccinations for immigration

The U.S. Immigration and Nationality Act requires everyone seeking an immigrant visa for permanent residency to show proof of having received vaccinations, according to ACIP guidelines. This requirement extends to all immigrant infants and children entering the United States. Although internationally adopted children <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 pre-travel 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.

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. In many countries, the measles vaccine is given alone (as a single antigen); it can also be combined with vaccines for mumps, rubella and/or varicella. Oral polio vaccine (OPV) received on or after April 1, 2016, is bivalent and should not be counted toward primary series completion. Vaccination with IPV or trivalent OPV is required to be fully protected against polio. Some children might be immune to hepatitis A, measles, mumps, rubella, or varicella because of natural infection. A previous 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. An 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 recommended, as they are considered immune after natural infection.

The following is an example of 1 possible approach to implementing a testing strategy. For internationally adopted 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 1, 2016, many resource-poor countries have used bivalent OPV; for children born on or after this date who do not have documentation of receiving IPV according to an approved (U.S. or World Health Organization) schedule, administer the age-appropriate vaccine series. Revaccination (or, for some, initial vaccination) with pneumococcal vaccine is recommended because the vaccine has 15 or more 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 CBC with a differential (as previously noted). Children of African, Asian, Hispanic, or Mediterranean ethnicity should also receive testing for hemoglobinopathies and blood disorders, including sickle cell disease, thalassemia, and glucose-6-phosphate-dehydrogenase (G6PD) deficiency. 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 25-hydroxy vitamin D. 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.