Japanese encephalitis

This code identifies a severe viral infection of the central nervous system transmitted by mosquitoes, specifically the Culex species. It is characterized by inflammation of the brain, often leading to neurological deficits, seizures, and altered mental status. The disease is endemic to Southeast Asia and the Western Pacific.

Assign this code for confirmed cases of Japanese encephalitis based on laboratory testing (e.g., serology, PCR) or strong clinical evidence in an endemic area. It is appropriate when the patient presents with symptoms such as fever, headache, vomiting, and signs of encephalitis following exposure in a high-risk region.

• Ensure documentation specifies "Japanese encephalitis" to differentiate from other forms of viral encephalitis.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter.
• Do not confuse with other arboviral encephalitides (e.g., West Nile, St. Louis encephalitis) unless specifically documented.