Tuberculosis cases reached an all-time low in the United States in 2005, but progress toward elimination of the disease has slowed, according to the Centers for Disease Control and Prevention.
Moreover, the number of multidrug-resistant (MDR) TB cases increased 13.3% from 2003 to 2004, marking the largest 1-year increase in such cases since 1993. A greater proportion of foreign-born patients than U.S.-born patients had MDR TB, the CDC said (MMWR 2006;55:305–8).
In 2005, a total of 14,093 TB cases was reported in the United States, representing a decline of 3.8% from 2004 and the lowest recorded rate (4.8 per 100,000 population) since national reporting began in 1953. However, the decline has slowed from an average of 7.1% per year during 1993–2000 to 3.8% per year during 2001–2005.
In 2005, the TB rate in foreign-born persons in the United States was 8.7 times that of U.S.-born persons. Although the total foreign-born population in the United States has increased 61.6% since 1993, the number of TB cases reported in this population hasn't changed substantially, resulting in a 36.0% decline in the TB rate among foreign-born persons. More than half of the 7,656 foreign-born TB patients in 2005 were from Mexico, the Philippines, Vietnam, India, and China, the CDC said.
Race/ethnicity data showed that TB rates in 2005 were increased 19.6 times among Asian Americans, 8.3-fold among blacks, and 7.3 times among Hispanics, compared with whites. But rates declined in almost all racial and ethnic populations from 2003 to 2005, with the most decline among American Indians/Alaska Natives (14.4%) and Asian Americans (14.1%).
The number of MDR TB cases increased from 113 cases in 2003 to 128 in 2004, the most recent year for which complete drug-susceptibility data are available. In 2004, 0.6% of U.S.-born and 1.6% of foreign-born TB patients had MDR TB. Approximately half of the foreign-born patients with MDR TB in 2004 were from Mexico, the Philippines, and Vietnam, the CDC said.
Also reported in the same MMWR issue, the first-ever data from the CDC and the WHO on rates of TB resistant to both first- and second-line antibiotics indicate that “extensively drug-resistant” TB accounted for 2% of all the MDR strains worldwide during the 2000–2004 period (MMWR 2006;55:301–5).