In Friday’s issue of the Morbidity and Mortality Weekly (MMWR), the Centers for Disease Control and Prevention released the 2009 statistics from the National TB Surveillance System. The results were encouraging as a decrease in total cases was seen from 2008 to 2009.

To arrive with their numbers, health departments in the 50 states and the District of Columbia (DC) electronically report to CDC the TB cases that meet the CDC/Council of State and Territorial Epidemiologists case definition.

The CDC calculates national and state TB rates overall and by racial/ethnic population using current U.S. Census population estimates. A U.S.-born person was defined as someone born in the United States or in its associated jurisdictions, or someone born in a foreign country but having at least one U.S.-born parent. Persons not meeting this definition were classified as foreign born.

Here are some of the numbers:

• In 2009, there were a total of 11,540 TB cases reported at a rate of 3.8 cases per 100,000 population. In 2008, the TB rate was 4.2 cases per 100,000 population; this represents a 11.4 percent decrease.

• That represents the greatest single year decrease since surveillance began in 1953.

• Foreign born persons and racial/ethnic minorities have a disproportionately higher amount of TB cases than the population as a whole.

• The TB rate in foreign born persons was almost 11 times higher than in US born persons.

• TB rates in blacks and Hispanics was about 8 times higher than among non-Hispanic whites.

• TB rates in Asians were over 25 times higher than non-Hispanic whites.

• The lowest rate of TB in any state was in Wyoming (0.4 per 100,000 population)

• The highest rates were seen in Hawaii (9.1 per 100,000 population)

• Four states accounted for more than half of all TB cases reported (50.3%); California, Florida, Texas and New York.

• The total TB cases in US born persons in 2009 were 4,499, as compared with 5,282 cases in 2008.

• The total TB cases in foreign born persons in 2009 were 6,806, as compared with 7,602 cases in 2008.

• Four countries accounted for more than half of the TB cases reported in foreign born persons (50.1%); Mexico, the Philippines, India and Vietnam.

• Over 10 percent of people with TB were co-infected with human immunodeficiency virus (HIV).

The CDC points out that the overall decreases in TB cases may be due to changes in population demographics or better TB control; or does it represent increased underreporting or under diagnosis of TB?

The investigation continues…