March 20 (HealthDay News) -- Tuberculosis cases reached an all-time low rate in the United States last year, according to a new federal government report.
The U.S. Centers for Disease Control and Prevention reported 12,898 new cases of TB in 2008, which equals 4.2 cases per 100,000 people.
However, the CDC report also noted that progress in eliminating tuberculosis has slowed in recent years, with a 3.8 percent average annual rate of decline between 2000 and 2008, compared with a 7.3 percent rate of decline from 1993 to 2000.
In 2008, TB rates ranged from 0.5 per 100,000 in North Dakota to 9.6 per 100,000 in Hawaii, the study said. Although 33 states and the District of Columbia reported lower rates in 2008 than in 2007, 17 states had higher rates.
Four states -- California, Florida, New York and Texas -- reported more than 500 TB cases each in 2008. Combined, these four states accounted for 49.2 percent of all TB cases in the country last year. In 2007, five states had at least 500 cases, and seven states recorded that many in 2006.
People from racial and ethnic minorities and foreign-born residents continue to be disproportionately affected by TB, the CDC said. Rates among Hispanics, blacks and Asians were 7.5, 8.1 and 23.4 times higher, respectively, than among whites in 2008. The TB rate among foreign-born residents was 20.2 cases per 100,000, which is 10 times higher than the two cases per 100,000 among people born in the United States.
The analysis of 2008 data also showed that among the 7,652 people with TB who have a known HIV test result, slightly more than 10 percent were confirmed to have HIV.
In addition, the report found that a type of TB that is resistant to at least two important first-line drugs -- isoniazid and rifampin -- accounted for 1.2 percent (125) of all TB cases in the United States for which drug-susceptibility data were available.
The findings, which came from analysis of data from the National TB Surveillance System, were published in the March 20 Morbidity and Mortality Weekly Report, published by the CDC.
The authors of the report said that more action is needed to tackle the slowing decline in TB rates and the continuing disparities between minorities and whites and between people born in the United States and those born elsewhere.
Tuberculosis cases had declined steadily in the United States in the three decades from 1953, when there were 84,304 reported cases, to 1985, with 22,201 cases. But the number of cases rose again, by 20 percent, between 1985 and 1992, when 26,673 cases were reported. This led to renewed TB prevention and control efforts during the 1990s, but the average annual decline has slowed since 2000.
Worldwide, about 2 billion people are infected with TB-causing bacteria. In 2006, about 9.2 million people became ill from TB and 1.7 million died from the disease. March 24 is World TB Day.
SOURCE: U.S. Centers for Disease Control and Prevention, news release, March 19, 2009