Nearly a third of the world?s population is infected with the bacterium that causes tuberculosis, according to a report published on Tuesday, with 7.96 million new cases of the disease reported in 1997. Southeast Asia accounted for the largest number of tuberculosis cases, with 44 percent of the area?s population infected. More than half of the new cases reported in 1997 occurred in five Southeast Asian countries.

The study estimated that in the 212 countries monitored by WHO, 1.86 billion people, or 32 percent of the global population, now carry the bacterium that causes the disease. The study said people are sometimes not aware they have tuberculosis because their bodies respond so effectively that infected areas heal. However, the disease can become active again when the immune system weakens or when the victim becomes malnourished.

The Journal of the American Medical Association 1999;282:677-686.  

COMMENT: It is quite amazing that so many people are infected with TB. It is also interesting to note that although one third of the population is infected, only 8 million people come down with the disease. I am not certain of the current population of the world, but it is around 4 or 5 billion, and perhaps higher. This means that 0.2% of those infected with TB actually acquire it. This is a very powerful statement that the person?s immune system, NOT THE BUG, is what is responsible for coming down with the disease.