2005 - Arboviral Encephalitis

Arboviral Encephalitis

Indiana residents are at risk for four arboviral encephalitis viruses: 1) eastern equine encephalitis (EEE), 2) St. Louis encephalitis (SLE), 3) La Crosse encephalitis, and
4) West Nile virus (WNV). La Crosse encephalitis and West Nile virus will be addressed in separate sections of this report.

Eastern equine encephalitis is caused by a virus transmitted to humans and equines (horses) by infected mosquitoes and is maintained in a bird-mosquito cycle in fresh water swamps. In Indiana, the ecological system that supports the transmitting mosquito, Culiseta melanura, occurs only in the north central counties. Horse and human cases occur sporadically. No human cases of EEE were reported in Indiana from 2001-2005.

St. Louis encephalitis (SLE) is also caused by a virus and is the most common mosquito-transmitted human pathogen in the United States. The virus is maintained in a bird-mosquito cycle involving the Culex species of mosquito. There were no reported cases of SLE in Indiana in 2005, and only one reported case in the five-year period 2001-2005.

You can learn more about arboviral encephalitis by visiting the following Web site: