Half of U.S. TB cases in four States

Source: Centers for Disease Control and Prevention. Trends in Tuberculosis – United States, 2012. MMWR 2012; 61: 181-185.

National data available for 2011 indicate that a total of 10,521 new TB cases were reported last year in the United States (incidence 3.4 cases/100,000 population), representing an overall decline of 3.8% from 2010. TB continues to disproportionately affect foreign born persons, and Asians became the single largest racial/ethnic group affected by TB, with a case rate 25 times higher than non-Hispanic whites. TB cases among Hispanics and non-Hispanic blacks fell slightly, but remained 7 and 8 times higher than non-Hispanic whites, respectively.

Remarkably, half (50.4%) of all TB cases in the United States occurred in 4 States in 2011 (California, Florida, New York, and Texas), although the case rate per population was the highest for Alaska (case rate 9.3 per 100,000 population).

Since 2000, a steady increase in TB has been observed in foreign born persons, with 62.5% of all TB cases in 2011 occurring in those who are foreign born. In contrast, cases in U.S.-born persons declined to a rate of 1.5 cases/100,000 population – an 80% decrease from 2003.

HIV test results were available for 81% of reported cases; among those with an available HIV test result, 7.9% were co-infected with TB and HIV.

Finally, drug resistance data (which was only available for 2010 and not yet available for 2011) indicates that 1.3% of all cases were multi-drug resistant. This figure is relatively stable compared with 2009. A total of 109 cases of MDR-TB and 4 cases of XDR-TB (all in foreign-born individuals) were reported in 2010. The risk for MDR-TB was four times greater in persons previously treated for TB compared with those receiving first time therapy.

Programs targeting high risk ethnic groups have been associated with a lower risk of reactivation TB. For example, one program targeting predominantly black and Hispanic neighborhoods in Texas, emphasizing INH treatment for anyone with latent TB, resulted in a definite decrease in active TB cases. Perhaps larger clinics in certain high risk areas of the United States, like Sutter Health and the Kaiser Permanente systems could consider similar programs.