U.S. tuberculosis rate in 2008 at record low

Tuberculosis rates in the U.S. reached a record low in 2008, but the disease still disproportionately affects minority and immigrant populations, according to a CDC report released Thursday in the agency's Morbidity and Mortality Weekly Report, Reuters reports.

According to CDC, the U.S. in 2008 recorded a TB rate of 4.2 cases per 100,000 people, which is a 3.8% decline from the 2007 rate. The agency said the 2008 rate was the lowest recorded since the start of national recording in 1953. However, it also added that the rates of decline have leveled off, noting that TB rates declined by an average of more than 7% each year between 1993 and 2000. CDC also reported that the U.S. recorded the lowest number of new TB diagnoses in 2008, with 12,898 new cases.

Robert Pratt of CDC's Division of TB Elimination in the report said that TB "continues to disproportionately affect racial/ethnic minorities and foreign-born persons." The report found that compared with whites, TB rates are 23 times higher among Asians, eight times higher among blacks and 7.5 times higher among Hispanics. The report also found that about 41% of new TB cases occurred among people born in the U.S.

According to CDC, more than 10% of HIV-positive people in the U.S. have contracted TB, likely because the virus weakens the immune system. The CDC report also found that multi-drug resistant TB accounted for slightly more than 1% of all U.S. TB cases in 2008. According to Reuters, the World Health Organization is expected to release new data on the global MDR-TB burden to mark World TB Day on March 24. According to the agency's latest data, about 5% of the nine million new TB cases diagnosed annually worldwide are drug-resistant (Fox, Reuters, 3/19).

The CDC report is available online. Additional TB-related articles in the latest version of MMWR also are available online.