TB control: role of DOTS.

Tuberculosis is a major cause of morbidity and mortality, particularly in many developing countries with significant public-health problems. Nearly a third of the world’s population is infected with Mycobacterium tuberculosis or is at risk of developing TB in the future. There was an estimated incidence of 9.27 million new cases of TB in 2007 (139 per 100,000 population), which has steadily increased from 9.24 million cases in 2006 (140 per 100,000 population), 8.3 million in 2000 and 6.6 million cases in 1990. A total of 1.32 million TB-related deaths occurred in HIV-negative people, with an additional 0.46 million TB deaths in HIVpositive individuals. The prevalence of TB cases worldwide is 13.7 million, 687,000 of which were HIV-positive cases. The majority of TB infections occur in Asia and Africa, contributing 55 and 31% of the total TB cases, respectively. Of these 9.27 million new cases, approximately 44% or 4.1 million (61 per 100,000 population) were new smear-positive cases. India, China, Indonesia, Nigeria and South Africa rank first to fifth in terms of the total number of cases. Of these cases in 2007, an estimated 1.37 million individuals (14.8%) were HIV positive. The African region accounts for most (79%) of HIV/TB coinfection cases, followed by the