Community-acquired Legionnaires' disease in Dallas County, Texas

Community-acquired Legionnaires' disease (LD) cases reported in Dallas County, Texas, from 2000 through 2010 were analyzed to determine the characteristics of disease incidence and burden of community-acquired LD and identify any temporal or geographic variation of the disease occurrences. As elsewhere in the U.S., annual reported cases of LD increased in the county, rising 380% from 2000 to 2010. Almost all cases were sporadic. Clustering of cases both geographically and temporally was observed and cases were found to be concentrated in the northern and eastern parts of the county. The rising incidence of community-acquired LD may require development of a public health policy that takes into consideration risk factors, particularly age. An environmental study would be helpful to identify modifable environmental factors in the areas with clustered cases.