A84.9

Approximate Synonyms

• Tick-borne viral encephalitis

• Viral encephalitis, tick borne

Clinical Information

• Encephalitis caused by neurotropic viruses that are transmitted via the bite of ticks. In europe, the diseases are caused by encephalitis viruses, tick-borne, which give rise to russian spring-summer encephalitis, central european encephalitis, louping ill encephalitis, and related disorders. Powassan encephalitis occurs in north america and russia and is caused by the powassan virus. Aseptic meningitis and rarely encephalitis may complicate colorado tick fever which is endemic to mountainous regions of the western United States. from Joynt, Clinical Neurology, 1996, ch26, pp14-5)

Details

• A84.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

• The 2023 edition of ICD-10-CM A84.9 became effective on October 1, 2022.

• This is the American ICD-10-CM version of A84.9 – other international versions of ICD-10 A84.9 may differ.