Medical Resources :: Common Diseases :: Infectious Diseases & Parasites :: International Adoptions Pose Extra TB Risk

Children adopted from abroad are special in a way neither their delighted adoptive parents nor their pediatricians may have guessed, experts say. For several reasons, they're at a particularly heightened risk for tuberculosis. For one thing, too many American pediatricians mistakenly believe that the BCG vaccine - which is administered routinely in almost all countries except the United States - means that children either don't need to get a PPD skin test or that the test won't be valid, experts say. As a result, such children often fail to be screened.

Failing to skin-test kids adopted from abroad "is a serious, serious problem," says Jane Aronson, MD, chief of pediatric infectious diseases, and director of the International Adoption Medical Consultation Services at Winthrop-University Hospital in Mineola, NY. "If I don't take responsibility for [PPD skin-testing,} there's a tremendous amount of laxness on the part of these kids' pediatricians." There are two mistaken assumptions that contribute to the problem, says one nationally recognized expert in the field. "There's the 'Oh, he's had BCG, so I don't have to worry about it' attitude," says Margaret Hostetter, MD, the American Legion Heart Research professor at the University of Minnesota in Minneapolis, and co-director of the International Adoption Clinic at the University of Minnesota Hospital Pediatric Clinic. "Then there's the 'Oh, he had BCG, so I can't possibly test for TB' attitude." Both beliefs are dead wrong, she adds. "There's abundant evidence in the literature that BCG is not 100" efficacious" at preventing TB, she says. Though the vaccine does provide substantial protection against disseminated forms of TB (such as TB meningitis), it offers at best only partial protection against pulmonary TB, Hostetter says - probably between 60% and 70%.

Last year, there were 11,340 international adoptions in the United States, according to statistics from the U.S. Immigration and Naturalization Service. That included 2,454 children from Russian and 3,388 from China, says Lauri Miller, MD, director of the International Adoption Clinic at the New England Floating Hospital in Boston. Between 50% and 60% of kids adopted from abroad in the United States each year come from China, Russia, and Eastern European countries, all places where the incidence of TB is significantly higher than in the Unites States.

Along with being at a heightened risk for TB, the kids often are afflicted with an assortment of other conditions, from intestinal parasites to Hepatitis B virus carriage to elevated lead levels, says Aronson. Health care screening for such children "is an issue that's evolving," she says. "It's the first time we've had huge numbers of children coming to this country from abroad over the last five to ten years. The protocol and guidelines are still being developed." Jeffrey Starke, MD, assistant professor of pediatrics at Baylor College of Medicine in Houston, agrees.

"Foreign-born kids in general are a very special group that we have, for the most part, neglected," he says. With only a handful of experts in the United States who specialize in kids adopted from abroad, responsibility for the problem falls squarely onto local pediatricians, says Starke, so they "had darn well better be familiar with what's going on." If pediatricians fail, kids wind up paying for it one way or another, Aronson says. "These are the kids who will end up with TB 20 years or 30 years down the road," she says.

Indeed, when the guidelines from the Red Book Guide to Pediatric Infectious Disease are applied to interpret the tests, at least 15% of such kids turn up with positive skin tests, says Miller. Obviously, most of the reactors are merely infected. But occasionally, failure to screen and treat leads to active disease going undetected, resulting in some scary situations, says Aronson. Take the case of a youngster adopted from the Philippines whose pediatrician didn't bother with a PPD skin test. By the time he got to Aronson, he was comatose with TB meningitis, she says. (Luckily he recovered; Aronson is still in contact with his grateful family.) Then there's the worried New Jersey father who used to call Aronson frantically on a regular basis. "His daughter had a positive PPD, had his pediatrician has been fighting with him" about whether the child should be placed on isoniazid prophylaxis, Aronson says.

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Caregivers Could Have Spread Disease

As often-unrecognized factor that adds to the risk of TB in kids adopted from abroad is the fact that many children come from orphanages, where childcare workers themselves may be spreading the disease. "These [workers] are people with poor-paying jobs and no health care," says Aronson. A colleague in Russia sent Aronson an alarming message recently. "She says she's seeing an amazing amount of TB, and many of these [cases] are caretakers in institutions for babies and in orphanages." Obviously, contact tracing simply isn't feasible in such situations. "The staff in the orphanages are so variable," says Miller. "It could be one person who came in to clean the floor for three days in a row and coughed on 12 babies. Plus, we're talking literally about thousands of orphanages."

That means kids adopted from abroad who come from orphanages may need to be evaluated as cautiously as if they come from a household with an adult contact, experts say. "We usually say they're PPD positive at 10 mm [induration] if they're coming from an endemic area," Hostetter says. "But with children coming from an orphanage, that's akin to a household contact of an active adult case. So if I've got an orphanage child whose Mantoux is 5 mm, and I'm concerned, I'll take a chest x-ray. If it's negative, I'll put the child on prophylaxis."

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BCG Cross-Reaction Tends to Wane

That leaves the BCG factor to puzzle over. Even though experts agree that a history of a BCG vaccination is no excuse not to skin-test, most say the vaccine's effect on the PPD skin test is variable and can be tricky to gauge. On one hand, it's wrong to think a BCG always yields a false-positive reaction to the tuberculin skin test. Yet clearly, it can produce a false positive, at least for a time. When that happens, the false-positive reaction tends to wane over time, experts say. "You can actually get a BCG and have no skin-test positivity at all," notes Aronson. Miller agrees. "We've put skin tests on hundreds of kids with BCG scars, and most of them have no reaction whatsoever," she says. On the other hand, kids who've had multiple BCGs will almost always have a positive reaction, adds Aronson.

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Records Inaccurate, Unreliable

History taking can also pose problems. Adoption records are often incomplete or misleading, experts say; but without a scar, it's often impossible to confirm whether a child has really had a BCG vaccination. "We often have a recorded BCG but no scar - which makes me very suspicious," Miller says. "Also, we don't know if the BCG being used is adequate." That's one of many reasons the experts are reluctant to make blanket statements about the relationship of the BCG vaccine to PPD skin tests.

Though most positive reactions in children who've had a BCG vaccine do wane after a year, "a lot of children are going to have a 5 to 6 mm induraction, even if they're a year and a half out," Hostetter says. In most cases - but not all, she emphasizes - when a child has a history of BCG vaccination, a positive TB skin test (ex. 9-11 mm induration) and no evidence of active disease, it makes sense to wait a few months and then re-rest to see if induration has waned, Hostetter says. (Bear in mind, she adds, that each case must be judged on its own merits.)

Whether to test for anergy when test for tuberculin reactivity is another thorny subject. "When we put ona Mantoux skin test, we also put on a Candida as a control," say Hostetter. "We think that's very important. In a study of Korean children, we found that about 11% of them were anergic." The figure probably rises to as high as 15% or more among children coming from China, Russia, and Eastern Europe, she adds.

There are other good reasons to test for anergy in foreign-born adopted children, Starke says. In states where it's hard to get permission to do HIV testing, the anergy test functions as "a potential surrogate test for HIV." Plus, testing (and subsequent re-testing, if indicated) for anergy can give useful information about a child's immune function, he says. "These kids may have other medical conditions, particularly malnourishment, so they may be anergic on that basis," he says.

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Wait for Immune Systems to Recover

Hostetter agrees. "If we're worried there are respiratory symptoms [in an anergic child], we'll take a chest X-ray," she notes. "Otherwise, we'll typically wait three or four months and just re-test them.. By that time, they'll have gotten some decent nutrition, and their immune system may have started to turn around. Miller, on the other hand, doesn't bother with anergy testing. "We used to do it. But to be honest, it was too cumbersome, and it seemed like an extra burden on the kids - they get poked and prodded enough. Despite the extra effort and added stress, working with children adopted from abroad is rewarding, says Aronson. Take that worried dad from New Jersey and his daughter. "He just e-mailed me yesterday to let me know his daughter finally got her INH," says Aronson. "He was so thankful. It's joyful work."

For more information about tuberculosis, read Tuberculosis, Latent Tuberculosis, TB and Other Infectious Diseases, or Tuberculosis in Children Adopted from Abroad in the Medical Resources/Information on Common Diseases/Infectious Diseases and Parasites section of this site.

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