Geographic information systems analysis to focus TB screening among people born in endemic countries

<sec><title>BACKGROUND</title>Geographic information systems may help focus TB screening and treatment efforts to populations in greatest need, such as people born in endemic countries (PBEC).</sec><sec><title>DESIGN/METHODS</title>North Carolina USA census and TB surveillance data were used to examine the relationship between the population proportion of PBEC and incident TB cases in the subsequent 5-year period by census tract. Census tract population:incident TB ratios for thresholds of PBEC were used to measure screening efficiency.</sec><sec><title>RESULTS</title>Of 3,290 PBEC TB cases, 2,764 (84%) had a mappable address. The proportion of census tract PBEC during 2006-2010 was strongly associated with incident TB in that tract in 2011-2015 (<i>p</i> < 0.001). Thresholds of 6%, 12%, and 19% PBEC in a tract during 2006-2010 as cutoffs for screening would have detected 75%, 50%, and 25% of incident TB cases in 2011-2015 with respective population:incident TB ratios of 11,840, 6,864, and 5,524 population/case. The same thresholds using 2011-2015 census data would have detected 75%, 50%, and 25% of incident TB cases during 2016-2018 with population:incident TB ratios of 17,804, 10,807, and 7,031 population/case.</sec><sec><title>CONCLUSION</title>Census tract demographics are a simple and powerful tool to focus targeted testing and treatment of latent TB in areas likely to have incident TB disease.</sec>.