Mosquito-Borne Viral Diseases

Worldwide, the list of mosquito-borne diseases is growing due to increased international travel, global commerce, and the clearing of new lands for human habitation. Mosquito-borne viral diseases include those that cause hemorrhagic fever and neurologic disease. West Nile virus, which was first detected in the Western hemisphere in 1999, is one of several encephalitic viruses that now appears to be endemic in the United States. The curious evolution of the once relatively innocuous infection of birds is now causing deaths in birds, horses, and man. The incidence and fatality rate of West Nile virus in the United States is comparable to that of St. Louis encephalitis virus. Other than the supportive care typically provided to encephalitis patients, no treatments are available for persons with symptomatic West Nile virus infection. Dr. Sanchez presents the compelling recent history of the identification of West Nile virus infection in humans in New York in 1999 and the spread of West Nile virus through the United States. Only four states in the continental US have not reported laboratory-confirmed cases of West Nile virus infection.