Tuberculosis cases at an all-time low in the U.S., the CDC says

The number of tuberculosis cases in the United States reached an all-time low last year, with only 11,181 cases reported to public health authorities, according to the Centers for Disease Control and Prevention. That represented a 3.9% drop in the number of cases from the preceding year, but was a disappointment on two counts: the number of cases had dropped by 11.9% in 2009, and authorities had hoped a major decline would continue; and in 1989, health officials had set a goal of eradicating TB in the U.S. by 2010, a roadmark that was clearly not met.

The agency reported in its Morbidity and Mortality Weekly Report that nearly 40% of the cases, 4,378, were in people born in the United States. The remaining 6,707 cases were in people who were born abroad. More than half of those cases were among people born in four countries: Mexico (23%), the Philippines (11%), India (8.6%) and Vietnam (7.7%). Overall, foreign-born people were 11 times as likely to have TB as those born in this country.

Four states -- California, Texas, New York and Florida -- accounted for 49.2% of the TB cases, a total of 5,503 cases. More cases were reported among Hispanics than any other ethnic group, but Asians had the highest case rate. TB rates among Hispanics, blacks and Asians were seven, eight and 25 times as high as among Caucasians, respectively.

Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis. It can be cured with antibiotics, but a full course of treatment requires six to nine months to fully eradicate the microorganism. Many people do not finish the full treatment, which leads to the development of drug-resistant strains of the bacterium. According to the CDC, nearly 94% of those who began treatment in 2007 completed their regimen.

The survey of TB cases detected 113 cases of so-called multidrug-resistant TB, which is caused by a bacterium that is resistant to at least two different antibiotics. The researchers found only one case of extensively drug-resistant TB, which is caused by a strain that is resistant to virtually all the antibiotics used to treat TB. Both forms of the disease are growing problems around the world because they are spreading rapidly and are extremely difficult to treat. The World Health Organization on Wednesday called for more funds for research and treatment of drug-resistant TB.