LAC encephalitis is rare; in the United States, about 80–100 LACV disease cases are reported each year, although it is believed to be under-reported due to minimal symptoms experienced by many of those affected.

Severe disease occurs most commonly in children under the age of 16 and is characterized by, and seizures, coma, paralysis and permanent brain damage and a variety of neurological sequelae after recovery.

In many clinical settings, pediatric cases presenting with CNS involvement are routinely screened for herpes simplex or enteroviral causes.

LAC virus is a zoonotic pathogen cycled between the daytime-biting treehole mosquito, Aedes triseriatus, and vertebrate amplifier hosts (chipmunks, tree squirrels) in deciduous forest habitats.

The risk is highest for people who live, work or recreate in woodland habitats, because of greater exposure to potentially infected mosquitoes.

[citation needed] People reduce the chance of getting infected with LACV by preventing mosquito bites.

[4] No specific therapy is available at present for La Crosse encephalitis, and management is limited to alleviating the symptoms and balancing fluids and electrolyte levels.

In a trial with 15 children being infected with La Crosse viral encephalitis were treated at certain phases with ribavirin (RBV).

It has long been suspected that LAC encephalitis has a broader distribution and a higher incidence in the eastern United States, but is under-reported because the causal agent is often not specifically identified.