Western equine encephalitis

This code represents an acute arboviral infection of the central nervous system caused by the Western equine encephalitis virus. It typically manifests as encephalitis, characterized by inflammation of the brain, and can range from mild febrile illness to severe neurological dysfunction.

Apply this code when documentation confirms a diagnosis of Western equine encephalitis, often supported by laboratory confirmation (e.g., serology, PCR). This code is appropriate for both initial and subsequent encounters related to the acute phase of the infection.

• Ensure documentation specifies "Western equine" to differentiate from other forms of viral encephalitis.
• Do not confuse with other arboviral encephalitides (e.g., Eastern equine, St. Louis encephalitis) which have distinct codes.
• Code any associated neurological sequelae or complications separately, linking them to the encephalitis as appropriate.