Infectious Diseases

Hepatitis B

Hepatitis B (HBV), a viral disease which affects primarily the liver, is endemic in most countries placing children in the United States. The virus is transmitted from one person to another by percutaneous (needle stick or biting), mucus membrane or sexual exposure to infected bodily fluids, particularly blood and serous fluid from exudative (weeping) skin lesions. Saliva and semen carry smaller quantities of the virus. The close confines of institutional care settings increase the risk of transmission.

When adults and older children are exposed to hepatitis B, most fight the infection effectively and clear the virus from their systems. However, the immature immune systems of infants and very young children may not identify this organism as an invader. These children do not clear the virus from their system and become chronic carriers of the hepatitis B virus.

They are then at risk for exposing others to the virus and for developing ongoing liver damage and liver cancer. Ninety percent of children infected in the first six months of life will have chronic, life-long disease. The risk of hepatitis B in international adoptees reflects the overall prevalence in the country of origin: 8-10% in Asia, sub-Saharan Africa and parts of South America; 2-7% in Eastern Europe and Northern China; <2% in Western Europe and the United States. In certain situations, such as the children emigrating from Romanian orphanages in 1990-91, the incidence was much higher (20%). Screening for hepatitis B after arrival is very important for the health of both your child and your family. An initial screening when the child first arrives in the U.S. and a second screening after the maximum incubation period of 12 weeks are recommended. The hepatitis B profile (see screening tests) rather than the simple testing for hepatitis B surface antigen should be utilized. In our experience, approximately 60% of the children with acute or chronic hepatitis would have been misdiagnosed if only the simple screening had been used.

The risk of transmission of hepatitis B to other family members has been examined. Rates of infection ranged from 5% to 37%, with increased infection risk when the adoptee was less than three years of age. While all household contacts are at risk for being infected, caregivers are at the highest risk of acquiring hepatitis B. The hepatitis B vaccine series is now universally recommended for newborns in the U.S. and is mandatory for household members when a family adopts a child who is hepatitis B surface antigen positive.

The health status of chronically infected Korean adoptees is generally good. However, most Korean children acquired their infections perinatally, while children from Romania were more likely to have person-to-person transmission. Experience with Romanian adoptees indicates a higher risk of abnormal liver function associated with chronic infection. Delta hepatitis virus has been recognized in a number of hepatitis B surface antigen positive adoptees. Therefore, a screening for antibodies to delta virus should be included in the evaluation of any child with chronic hepatitis B infection. All children with either acute or chronic hepatitis B infections should be referred to a pediatric liver or infectious disease specialist.

Hepatitis B: Interpretation of Laboratory Test Results  from the Minnesota Department of Health

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Hepatitis C

Hepatitis C (HCV) is a disease of the liver caused by the hepatitis C virus. It is found less commonly than hepatitis B, but it has been identified in international adoptees. In a study of 357 Chinese adoptees, approximately 1% were documented infected with hepatitis C compared with 3.5% with hepatitis B. The hepatitis C virus is found in the infected person’s blood and other body fluids. It can be passed from mother to baby at birth through vertical transmission or by horizontal transmission, including the transfer of blood from the infected person to another. Therefore, children born to mothers who have a history of drug use are at increased risk for the disease, as are children who received blood products in their country of origin. Most children with chronic hepatitis C appear healthy. However, they are at risk for long-term problems with liver disease, including cirrhosis and liver cancer. Once hepatitis C is diagnosed, the child should be referred to a pediatric gastroenterologist familiar with the follow-up and current treatment options for this disease.

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Parasites

Intestinal and cutaneous parasites are commonly encountered in international adoptees. In general, intestinal parasites are more common in older children and in countries where water treatment and sewage disposal standards are poor. Cutaneous parasites are ever present. While a number of different organisms can be identified, a few deserve special attention. Giardia lamblia is a waterborne parasite encountered very frequently in institutionalized children of all ages. Not only can Giardia cause distressing symptoms in your child, it is easily transmitted to other family members. Scabies and lice are extremely common cutaneous pathogens that can be difficult to diagnose and treat because of secondary skin infections. Prompt treatment is very important to avoid infection of other family members.

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Tuberculosis

What should I do if my child is diagnosed with tuberculosis?

Tuberculosis is an infection caused by the bacterium Mycobacterium tuberculosis, which differs in many ways from the bacteria that cause other childhood infections such as otitis or tonsillitis. Because of these differences, the usual antibiotics prescribed for simple childhood infections are not effective in tuberculosis.

Children are exposed to tuberculosis when they inhale the contagious sputum droplets of an infectious contact (usually an adult in their environment). These sputum droplets are spread by coughing, laughing, or even singing, so it is not difficult to see why infected adults, who can typically generate a more vigorous cough, are considered highly contagious and young infants are not. In populations where TB is endemic, infected adults may work in orphanages or nurseries or be part of a foster family. In other circumstances, TB may be passed from an infected mother to her child immediately after birth. These children are often extremely ill and many do not live beyond the early days of infancy, especially if poor nutrition and lack of medical care contribute to the severity of illness.

In TB infection, the usual focus is the lung, but untreated TB may spread more widely. For these reasons, the symptoms of TB may range from the relatively healthy child with mild wheezing or coughing to the more severely affected child with widespread disease involving the brain, lungs, bones, or kidneys. Children with very poor nutritional status and children who acquire TB very early in life are at increased risk for widespread disease.

After exposure to tuberculosis, the body's immune system develops a delayed hypersensitivity response, which is reflected in a positive TB skin test. The skin test remains positive even after appropriate treatment for TB. Thus, a positive TB skin test may mean either a previous exposure (infection without active disease), the presence of the actual disease, or a past infection that is now cured. Differentiating between these possibilities is clearly very important.

All adopted children from abroad, whether they appear healthy or ill, should receive the Mantoux (needle prick) intradermal skin test for tuberculosis. This test, known as a PPD, is more sensitive and specific than the multiple puncture test (Tine). Undernourished children may fail to respond to the Mantoux test even though they may have been exposed to TB. This type of negative reaction is called anergy and is related to the inability of the immune system to respond appropriately to the skin test. One way to control for the possibility of anergy is to place a Candida (yeast) skin test at the same time the Mantoux test is given. In children whose immune system is appropriately active, the Candida skin test will be positive, and a negative Mantoux test will then accurately reflect the child's never having been exposed to TB. Depending on the country of origin, 3-9% of international adoptees will have a positive skin test.

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In children under 18 months, the ELISA antibody test reflects the mother's passively transmitted antibodies. Thus, the test may be falsely positive if the mother is HIV-positive but the infection has not been transmitted to the child.

The ELISA test may also be falsely negative. More children are being reported who test negative on ELISA but are still proven to be infected when a culture or PCR is done. The ELISA turns positive later than the culture or PCR. For example, if a child is exposed to HIV via a contaminated syringe, blood product or vaccine three weeks before placement, his/her ELISA will not be positive (too soon), but the viral culture or PCR will be positive.

Our approach to screening for HIV has been to follow the recommendations of the American Academy of Pediatrics to use the ELISA antibody test for children six months of age or older soon after the child's arrival and then repeat the test six months later. A child with two negative tests performed in an interval of at least one month can be considered not infected. A child who is ELISA positive should then be further evaluated by an AIDS specialist to determine if she/he is truly infected with the virus.

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We are not presently culturing the urine of internationally adopted children for cytomegalovirus (CMV), because approximately 30-50% of adoptees are excreting this virus - the same percentage that we would expect to find in infants or toddlers in daycare in the U.S. Ordinarily, CMV acquired after birth is benign. However, special problems may arise for women who acquire their first CMV infection during a pregnancy, or for any person whose immune system is compromised after steroid use, chemotherapy or transplantation. Infants born to women who acquire a primary infection with CMV during pregnancy may have severe sequelae such as blindness, deafness or mental retardation. Immunocompromised hosts may have severe infections themselves, including pneumonia. In these populations, we recommend checking antibodies to CMV. If the antibody test is positive, then the patient has acquired CMV in the past and the risk of severe complications is low. If the antibody test is negative, then the patient should understand that CMV may be acquired from any of several sources: blood products, sexual partners, or infants or toddlers of any country of origin, including the U.S. Since there is no vaccine to prevent the transmission of CMV from an excreting infant to a caregiver, we recommend good handwashing and excellent personal hygiene when handling urine, diapers, or toys or other objects coated with oral secretions. The child who is toilet-trained presents virtually no risk.

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