Recurrent St. Louis encephalitis infection in residents of a flood plain of the Trinity River, Roosevelt Heights (Dallas, Texas).

Luby, J. P. and R. W. Haley (Univ. of Texas Southwestern Medical School at Dallas, Texas 75235). Recurrent St. Louis encephalitis infection in residents of a flood plain of the Trinity River, Roosevelt Heights (Dallas, Texas). Am J Epidemiol 96: 107-113, 1972.—A serologic survey was conducted among nonwhite persons residing in a circumscribed community (Roosevelt Heights) in Dallas, Texas, situated on a flood plain of the Trinity River. In total, 214 sera were collected. St. Louis encephalitis (SLE) neutralizing antibody was found in 13.6% of the sample and rates revealed a statistically significant trend to increase by length of residence, suggesting that this community had experienced recurrent SLE infection. Western equine encephalitis (WEE) antibody was found in 1.9% of the survey population. The finding of a community with recurrent SLE infection approximately 100 miles west of the towns that had previously been investigated was thought basic to the epidemiologic proof that an interaction did exist between the two established transmission cycles for SLE virus in Texas (SLE, WEE-Cufex tarsalis mosquitoes and SUL-Culex quinquefasciatus mosquitoes).