In the United States, tuberculosis is rare nowadays.

But in developing countries, it kills more people than any other infectious disease except AIDS.

The World Health Organization estimates that 490,000 children under age 15 develop tuberculosis each year, worldwide. However, a study published in The Lancet Global Health suggests the actual number may be about one-third higher.

The discrepancy comes because scientists have to somehow estimate the number of T-B cases that go unreported.

The World Health Organization assumes that unreported pediatric and adult cases occur at the same rate, 35 percent. Researchers in the new study disagree. They say 65 percent of pediatric cases go unreported.

Here’s the reason: Supposedly, health authorities often ignore pediatric cases because children with T-B pose little public health risk.

In the study, researchers looked at tuberculosis statistics collected from the 22 countries with the highest T-B incidence. They included India, China, Russia, Brazil and many African nations.

These countries account for about 80 percent of all tuberculosis cases worldwide.

The researchers took the number of reported cases in adults and extrapolated to estimate T-B rates in children.

Their results indicated that about 650,000 children develop tuberculosis in those countries every year.

And that’s not considering the 20 percent of cases that arise in other countries.

One could argue that the exact numbers don’t matter; the real problem is that pediatric tuberculosis should be a higher priority.

But maybe the revised estimates will encourage some government officials to revise their approach to fighting this deadly respiratory disease in their youngest citizens.