Venezuelan Equine Encephalitis
This is a mosquito-borne viral disease affecting rodents, horses, and people in Trinidad, Central America, Florida, and South America. Epidemics occur during rainy seasons.

After an incubation time of less than a week, a flu-like illness with fever, chills, nausea, vomiting, and diarrhea, will occur. The fever lasts up to 4 days but is followed by profound weakness of up to several weeks. Some people develop encephalitis.

Antibody tests confirm the diagnosis. There is no specific treatment, only supportive measures. A vaccine exists for lab personnel, but is unavailable to travelers as the disease is rare.

This is one disease the U.S military is concerned with being weaponized by terrorists because it incapacitates people, although there is no firm evidence of this having ever happened.

Venezuelan Equine Encephalitis links

Center for Disease Control