These infections generally occur during warm weather months when mosquitoes are active. The term encephalitis refers to an inflammation of the brain which an arbovirus infection can cause. In spite of the name, La Crosse encephalitis is not confined to the La Crosse County area. Anyone can get an arboviral infection. Susceptibility to disease is highest in infancy and old age.
Children appear to be most susceptible to La Crosse encephalitis.
Most arboviral infections are spread by the bite from an infected mosquito. Fortunately, only a few types of mosquitoes are capable of transmitting the disease and only a small number of the mosquitoes are actually carrying the virus. Symptoms of the various types of viral infections transmitted by mosquitoes are usually similar but differ in severity. Most infections do not result in any symptoms. Severe infections are marked by a rapid onset of headache, high fever, disorientation, coma, tremors, convulsion and infrequently paralysis or death.