Decreased tuberculosis incidence and declining clustered case rates, Madrid

Abstract

To determine effect of recent tuberculosis transmission rates on incidence rates, we conducted 2 prospective population-based molecular epidemiologic studies in Madrid during 1997-1999 (4% immigrants) and 2002-2004 (14.9% immigrants). Case rates decreased in association with declining clustered case rates among Spanish-born persons. New strains were introduced through immigration.