Arbovirus encephalitis refers to a group of infections that affect the brain and are caused by arboviruses, which are spread by mosquitoes, ticks, and other biting insects. Here are some key details:

Pathogens:

• Major families: Flaviviridae (e.g., West Nile virus, Japanese encephalitis virus), Togaviridae (e.g., Eastern equine encephalitis virus), Peribunyaviridae, and Rhabdoviridae.
• Common in North America: West Nile virus, La Crosse encephalitis, St. Louis encephalitis, Eastern equine encephalitis, and Western equine encephalitis.

Symptoms:

• The presentation is often subacute, with psychological manifestations, cortical dysfunction, movement disorders, autonomic dysfunction, and seizures.
• Imaging abnormalities may be present, such as focal abnormalities in Eastern equine encephalitis or hemorrhagic bilateral thalamic abnormalities in severe Japanese encephalitis.

Treatment:

• Supportive care is the mainstay, which may include management of elevated intracranial pressure, syndrome of inappropriate secretion of antidiuretic hormone, and respiratory support.
• No specific therapy is available, and outcomes can be severe, with devastating neurologic sequelae in survivors.

Epidemiology:

• Typically appears in clusters or epidemics from midsummer to early fall.
• State public health authorities provide updates on cases in specific regions.

Prognosis:

• Cases are often fatal, with survivors facing long-term neurological damage.