Health

Children Adopted From Poorer Countries May Need Repeat TB Test

By Nicole Ostrow

July 7 (Bloomberg) -- Children adopted in the U.S. from poorer countries may need a repeat test for tuberculosis, even after initial testing indicates they're free of the disease, a study found.

Of 203 children who tested negative for the disease and came back for a second test, 38 were found to have a latent infection that wasn't contagious, according to research in the July issue of the journal Pediatrics.

More than 20,000 children are adopted into the U.S. each year, and many come from countries where the rates of tuberculosis are high, according to the study. The American Academy of Pediatrics recommends these children be tested for the disease when they arrive. The findings from this study should make a second test standard, researchers said.

``If it's negative, it's very important that they go on and have a repeat tuberculosis skin test to be sure,'' said Mary Allen Staat, a doctor and director of the International Adoption Center at Cincinnati Children's Hospital Medical Center in Ohio, in a July 2 telephone interview. ``By identifying them and treating them, we're really hoping to prevent them from getting tuberculosis disease that could make them sick or make them contagious to others.''

More than 2 billion people, or one-third of the world's population, are infected with the bacteria that cause TB, according to the World Health Organization. In 2006, there were 9.2 million new cases of TB and 1.7 million people died from the disease.

Tuberculosis is caused by germs spread through the air. It generally affects the lungs, although it can attack the kidneys, spine or brain, according to the U.S. Centers for Disease Control and Prevention.

Test Results

Researchers in the study looked at 527 children who were tested for tuberculosis within two months of arriving in the U.S. Of those, 111, or 21 percent, tested positive for a latent form of the disease. Of the children who were negative, doctors retested 203 at least three months later.

The 38 children who had a positive second test were more likely to be malnourished at the initial visit than those who had a repeat negative test, according to researchers.

Children who are malnourished may not initially respond as well to the tuberculosis skin test, Staat said. With better nourishment, they tend to have a more accurate test result. Also, some children may become infected right before they leave their birth country, and it can take up to three months before that infection can be detected.

Missed Cases

``If we had not retested those children, we would've missed children that had a tuberculosis infection,'' she said. At the International Adoption Center, children are retested after six months.

Higher rates of TB were found in the study in children from Russia, China and Guatemala. While TB rates are also high in much of Africa, few children surveyed were from the continent.

People with a latent form of the disease aren't sick because the germs aren't active. They may develop TB in the future and are often prescribed medicine to stop that from happening.

Leonard Krilov, head of pediatric infectious diseases and the International Adoption Program at Winthrop-University Hospital in Mineola, New York, on Long Island, said the program advises parents to have their children retested for TB within three to six months after the initial test.

A baby infected with the latent form of TB has a 10 to 20 percent lifetime risk of developing an active form of the disease, said Krilov, who wasn't involved in the study, in a July 3 telephone interview.

Sarah Long, a member of the committee on infectious diseases for the American Academy of Pediatrics and a doctor at St. Christopher's Hospital for Children in Philadelphia, said based on these findings, the committee will likely take a look at its guidelines for tuberculosis testing for internationally adopted children.

In addition to tuberculosis, children adopted from other countries may be tested for HIV, hepatitis A, B and C, parasites and syphilis, she said in a July 2 telephone interview.

To contact the reporter on this story: Nicole Ostrow in New York at nostrow1@bloomberg.net.

Last Updated: July 7, 2008 06:00 EDT