HealthDay News — An abrupt decline in the number of reported tuberculosis (TB) cases among foreign-born persons in the United States began in 2007, according to research published online Feb. 10 in PLOS ONE.
Brian J. Baker, MD, of the US Centers for Disease Control and Prevention in Atlanta, and colleagues examined data from the US National Tuberculosis Surveillance System and the American Community Survey to identify contributing factors to the decline in reported TB cases among foreign-born persons.
The researchers found that among entrants who arrived in the United States less than three years ago there was a 39.5 percent decline in TB cases beginning in 2007 and ending in 2011. Among recent entrants from Mexico, 80.7 percent of the decline was due to a decrease in population; among those from the Philippines, India, Vietnam, and China, 95.5 to 100 percent of the declines were due to decreases in TB case rates. Among entrants who arrived in the United States three or more years ago there was an 8.9 percent decline in TB cases that was entirely due to a decrease in the TB case rate.
“Among recent entrants, the decline was associated with a decrease in TB case rate as well as a decrease in population, but this varied by country of origin,” the authors write. “In addition, non-recent entrants also substantially contributed to the decline, exclusively as a result of a decreasing TB case rate.”