One in four TB cases is a recent transmission, CDC reports

According to a study conducted by researchers from the U.S. Centers for Disease Control and Prevention, approximately one in four cases of tuberculosis in the U.S. is a result of recent transmission.

The study, which was published in the March issue of Emerging Infectious Diseases, also showed that men and those born in the United States at a higher risk for TB infection. In addition, members of ethnic or racial minority groups, the homeless and substance abusers also had higher infection risks, HealthDay reports.

Patrick K. Moonan and his colleagues analyzed genotype data from culture-positive TB cases that were reported between January 2005 and December 2009.

"Understanding transmission dynamics and establishing strategies for rapidly detecting recent transmission among these populations are essential for tuberculosis elimination in the United States," Moonan and his colleagues said, according to HealthDay.

According to the CDC, tuberculosis is caused by the Mycobacterium tuberculosis bacterium, which usually attacks the lungs but can also attack other parts of the body. TB spreads through the air from one person to another when a person with active TB coughs, speaks, sneezes or sings. Those who are nearby may breathe in the bacteria and become infected. Without proper treatment, TB can become fatal.