St. Louis encephalitis: clinical and epidemiologic aspects, Mississippi, 1974
Powell, K.E.; Blakey, D.L.
Southern Medical Journal 69(9): 1121-1125
1976
ISSN/ISBN: 0038-4348 PMID: 968523 Document Number: 107829
During July, August and September 1974, an epidemic of St. Louis encephalitis occurred in Memphis, Tennessee, with additional cases noted in western Tennessee, north-eastern Arkansas and Mississippi. The 17 confirmed and 6 presumptive cases in Mississippi were mainly in the north-west. Major activity of St. Louis virus had not previously been reported in these States. The clinical features of the Mississippi cases are discussed. There were no deaths. There were 229 reported cases of the disease in Mississippi in 1975, with 36 deaths. The 1974 outbreak had been foreseen because of an increase in antibody to St. Louis encephalitis in fledgling sparrows detected by the annual avian surveillance system. Chemical control measures directed against adults and larvae of the vector mosquitoes, of which the chief one in this part of the USA is Culex pipiens fatigans Wied. (C. p. quinquefasciatus auct.) were therefore intensified. The number of human cases is presumed to have been reduced as a result. Attack rates in urban and rural areas were similar.