These include China, India, Bangladesh, Pakistan, Indonesia, Russia and the Philippines. Of new TB cases, fully 95 percent are in the underdeveloped world. One third of the people in the world are believed to carry the tuberculosis microbe. Of the estimated 2 billion infected, one in ten are expected to develop active tuberculosis at some time in their lives. The bacterial infection can live for years in its host, causing chronic debilitation, and is often fatal.
Drug resistance is a wholly man-made phenomenon.
Selective mutation of the microbe burden in a host results from inadequate or intermittent drug supply for the patient or from the misuse of available anti-tuberculosis drugs. Health workers fear that the high cost of treating drug-resistant strains will be impossible in countries already reeling from several epidemics of infectious disease as well as social and political factors such as war, massive poverty and inequality and economic crisis. North America and Europe may have the billions of dollars required to contain this emergency. WHO estimates 50 million people worldwide are already infected with drug-resistant tuberculosis. Growing numbers of drug-resistant tuberculosis cases apparently are being contracted directly through breathing the same air as a person already sick from a resistant strain.