1999 - St. Louis encephalitis in the United States of America . Update
14 September 1999
Disease Outbreak Reported
An outbreak of St. Louis encephalitis (SLE), a viral infection transmitted by mosquitos, was reported for the first time in New York City in early September. Of the 11 serologically-confirmed cases, 3 have died. Another 80 cases are being investigated, of which approximately 10% are considered probable cases of SLE, based on clinical criteria.
Of the 11 cases mentioned above, 9 were in older adults aged 58-87 years; the other 2 were aged 38 and 15. The course of the illness in these younger patients has been less severe.
As the laboratory-confirmed cases were in residents of Queens (8), Brooklyn (1) and South Bronx (2), local authorities have undertaken vigorous measures to control the mosquito population, by spraying the entire city with malathion (by air) or resmethrine (on the ground). Active surveillance for human cases and mosquitos continues.