WASHINGTON — On World TB Day, March 24, there’s some sobering news about children and tuberculosis. A new study estimates that every year, 1 million children worldwide become infected with TB. That’s twice previous World Health Organization estimates and three times the number of youngsters who are reported, diagnosed and treated for the disease annually. More concerning still is news that 32,000 children are sick with multi-drug resistant tuberculosis, which is extremely difficult to treat.
Experts say there is a narrow window for identifying and treating children with the disease. Unlike adults, who can carry the bacterium in a latent form for many years before becoming ill, public health officials say kids infected with TB can become sick very rapidly, and may die before ever seeing a doctor.
Part of the problem is tuberculosis is very difficult to diagnose in children, according to Mercedes Beccera, a professor of Global Health and Social Medicine at Harvard Medical School in Boston.
Beccera said the conventional sputum test used successfully to diagnose TB in adults does not work very well in children. The test looks for the presence of bacteria in a sample of mucus coughed up by patients.
But Beccera, a senior author of the report on kids and TB published in the journal The Lancet, says the sputum test is not sensitive enough to pick up the disease in all youngsters.
“Children have less bacteria and their disease is actually different than adults. It presents differently,” explained Beccera.
In children, Beccera said, the TB bacteria often do not stay confined to the lungs. Often, the disease spreads to other parts of the body, including the brain and bone marrow.
Becerra and colleagues at Brigham and Women’s Hospital in Boston first looked into the number of cases of multi-drug resistant TB in children.
In the course of combing through regional and global estimates, they found about 1 million children overall developed TB in 2010, approximately double official estimates. Of these, researchers discovered that more than 30,000 pediatric cases were drug resistant.
Because children usually become infected with tuberculosis through exposure to sick adults, Beccera said that many cases of TB could be prevented by thoroughly screening those who come in contact with patients - including children.
Otherwise, Beccera said, failure to examine children is a missed opportunity to treat and prevent tuberculosis.
“Every single child with TB is a warning signal that TB transmission is ongoing around that child, and that children are not getting preventive therapy,” said Beccera.
Beccera said most cases of tuberculosis occur in China, Russia and India, but pointed out that children are becoming infected with tuberculosis anywhere adults are sick with the disease.