Tuberculosis Incidence Falls for 20th Straight Year

Joe Barber Jr, PhD

March 22, 2013

The number of cases of tuberculosis (TB) reported in the United States in 2012 fell for the 20th straight year, according to a report by the Centers for Disease Control and Prevention (CDC).

Roque Miramontes, MPH, and colleagues from the CDC in Atlanta, Georgia, reported their findings in the March 22 issue of Morbidity and Mortality Weekly Report.

According to preliminary data from the CDC National TB Surveillance System as reported by all 50 states and the District of Columbia, a total of 9951 new cases of TB were reported in 2012, a decrease of 6.1% compared with the number of cases in 2011. The rate of new cases of TB was highest among Asians (19.8 per 100,000 population), followed by blacks (5.7 per 100,000 population) and Hispanics (5.2 per 100,000 population).

In total, 6243 of the new cases of TB were reported among foreign-born individuals, a 4.1% decrease compared with the number of new cases in 2011. Regarding the cases of TB among foreign-born persons, the highest number of cases was reported for people from Mexico at 1303, followed by the Philippines (n = 768), India (n = 528), Vietnam (n = 450), and China (n = 351).

Overall, the TB rate among foreign-born persons was 11.5 times as high as that among US-born persons. Additionally, non-Hispanic Asians, Hispanics, and blacks had rates 25, 6.6, and 7.3 times as high as that in non-Hispanic whites, respectively.

The TB rates by state ranged from 0.4 per 100,000 population in West Virginia to 9.0 per 100,000 population in Alaska. Four states — California, Texas, New York, and Florida — each reported more than 500 new cases of TB in 2012, and these 4 states accounted for approximately 50% of all new cases in 2012 (n = 4967).

Among individuals with a known HIV status, 7.7% of those with TB were also HIV positive. Additionally, 5.6% of persons with TB who were at least 15 years of age revealed that they were homeless at some point within the past year, and 12.1% reported excessive alcohol use during the same period. Moreover, among individuals with TB who were at least 15 years of age, 4.2% were incarcerated at the time of TB diagnosis.

Multidrug-resistant TB made up 1.6% (n = 127) of all TB cases in the United States with drug-susceptibility testing completed in 2011 (the most recent year for which results are available). There was 1 case of extensively drug-resistant TB in 2012.

"Despite the decline in TB cases and rates from the previous year, the rate of 3.2 TB cases per 100,000 persons in 2012 exceeds CDC's TB elimination goal for 2010 of < 1 case per 1 million population," the authors write. "Although continued progress toward achieving TB elimination in the United States occurred in 2012, TB persists in some geographic regions and among foreign-born persons and racial/ethnic minorities…. Ongoing surveillance will be essential to shape targeted TB prevention strategies in the effort to sustain success toward TB elimination in the United States."

The authors have disclosed no relevant financial relationships.

MMWR Morb Mortal Wkly Rep. 2013;62:201-205. Full text