Nature
The St. Louis encephalitis is carried by the [Culex nigripalpus] mosquito, which feeds after sunset. Symptoms are flu-like and coma and death can result.
Incidence
In 1990, an outbreak of encephalitis in Florida resulted in 230 sick people and 11 deaths. In 1997, when warnings were issued that mosquitoes were again carrying the disease, precautions were taken to prevent any public infection.