Tuberculosis (TB) is the leading cause of death in the world from a bacterial infectious disease. The disease affects 1.8 billion people/year which is equal to one-third of the entire world population.
In the United States TB is on the decline. In 2007 a total of 13,293 cases were reported. The TB rate declined to 4.4 cases per 100,000 population, the lowest recorded rate since national reporting began in 1953. Despite this overall improvement, progress toward TB elimination has slowed in recent years; the average annual percentage decline in the TB rate slowed from 7.3% per year during 1993--2000 to 3.8% during 2000--2007. Also, since 1993 there has been a gradual decline in the number of TB patients with coinfection with HIV, and the number of cases of multiple drug-resistant TB has gradually dropped.