Culture-based screening strategy reduced incidence of immigration-related tuberculosis in U.S.

Implementation of the culture-based algorithm may have substantially reduced the incidence of tuberculosis (TB) among newly arrived, foreign-born persons in the United States, according to an article being published in Annals of Internal Medicine.

Immigration has a substantial effect on the incidence of TB, so immigrants and refugees bound for the United States are required to have overseas TB screening. Before 2007, a smear-based algorithm that could not diagnose smear-negative/culture-positive TB was used to screen this population. Since then, the Centers for Disease Control and Prevention revised the screening strategy to use a more inclusive culture-based algorithm. Researchers reviewed health records to determine the increase of smear-negative/culture-positive TB cases diagnosed overseas between 2007 and 2012 and compared that figure with the decline of reported TB cases among foreign-born persons within one year after arrival in the United States.

The data showed that the increased annual number of TB cases detected in immigrants and refugees closely matched in magnitude a decrease in the number reported TB cases, suggesting that the culture-based algorithm effectively reduced TB incidence.

Study: Effect of a Culture-Based Screening Algorithm on Tuberculosis Incidence in Immigrants and Refugees Bound for the United States: A Population-Based Cross-sectional Study, Y. Liu, D.L. Posey, M.S. Cetron, and J.A. Painter, Annals of Internal Medicine, doi: 10.7326/M14-2082, published 16 March 2015.