Figure. Estimated prevalence of latent tuberculosis infection, by county, United States, as derived from genotyped cases of tuberculosis reported to the US National Tuberculosis Surveillance System, 2011–2015. County equivalents (i.e., Alaska boroughs, District of Columbia, Louisiana parishes, and Virginia independent cities) are also shown. A modified method for analyzing data for Oklahoma is found in the text. Prevalence estimates for Alaska are aggregated by region.