1999 - West Nile fever in the United States of America (update on St. Louis encephalitis)
06 October 1999
Disease Outbreak Reported
As a result of further in-depth study, the outbreak in New York City reported as St. Louis encephalitis (SLE) on 14 September has now been confirmed to be due to West Nile fever.
On 23 September, 4 birds tested positive for West Nile-like virus, including 3 exotic birds from a local zoo and 1 crow from Westchester county. Following the finding of West Nile-like virus in this area, all human cases previously reported as SLE were retested. To date, 50 previously reported SLE cases have been confirmed as West Nile fever. Of these, 38 were among residents of New York City, while the others occurred in surrounding areas. There have been 5 deaths among older adults.
Surveillance for human cases, mosquitos and birds is ongoing, in close collaboration with the US Centers for Disease Control and Prevention (CDC) and health authorities in New York state. Laboratory-positive cases have also been reported in Nassau and Westchester counties and West Nile-like virus has been isolated from mosquitos and dead crows in southern Connecticut.