CDC says screen immigrants for TB before they enter the U.S.

Scientists at the Centers for Disease Control and Prevention (CDC) in the U.S. say immigrants coming into the country from Africa and Southeast Asia should be tested and treated for tuberculosis (TB) before they arrive in order to prevent the importation of the disease.

According to a study by researchers at the CDC, foreign-born immigrants have accounted for more than half (57%) of new tuberculosis cases in the U.S. in recent years.

The researchers say more than 53% of all TB cases in the U.S. among foreign-born persons occurred in the 22% of the population born in sub-Saharan Africa and Southeast Asia.

The CDC team led by Dr. Kevin P. Cain analyzed data on foreign-born persons in the United States diagnosed with TB from 2001 through to 2006 in order to discern which populations of foreign-born persons in the U.S. are at higher risk of TB and drug-resistant TB.

Out of a total of 46,970 cases reported among foreign-born persons in the U.S. during that period, 12,928 (28 percent) were among immigrants who had entered the country within the previous two years.

The study also revealed that while TB case rates declined over time among the foreign-born population overall, they remained higher than among U.S.-born persons, even more than 20 years after arrival....and were more than four times higher in 2006.

The drug-resistant TB was found to be the highest in countries including Vietnam, Peru, the Philippines and China.

On average, 250 individuals per year were diagnosed with smear-negative, culture-positive TB disease within 3 months of U.S. entry; 46% of these were from the Philippines or Vietnam.

The researchers believe that screening immigrants and refugees from the Philippines and Vietnam would have detected almost half the average 250 TB cases brought into the U.S. each year between 2001 and 2006.

The study is published in the Journal of the American Medical Association.