Other viral encephalitis, not elsewhere classified (A85)
The ICD-10 code A85 covers various viral encephalitis types that are not classified elsewhere, identifying infections of the brain caused by different viruses. This includes specific forms such as enteroviral, adenoviral, arthropod-borne, and other specified viral encephalitis.
The ICD-10 code for other viral encephalitis (A85) is used to document brain inflammation resulting from uncommon or unspecified viral agents. For example, A85.0 corresponds to enteroviral encephalitis, which is also known as echovirus encephalitis or enteroviral encephalomyelitis. A85.1 codes for adenoviral encephalitis, associated with infections like adenoviral meningitis or meningoencephalitis, and sometimes linked to AIDS-related conditions. A85.2 identifies arthropod-borne viral encephalitis, commonly called arbovirus encephalitis. The A85.8 designation is reserved for other specified viral encephalitis caused by a wide array of viruses, including the Epstein-Barr virus, Hendra virus, and various arboviruses and retroviruses. These codes help healthcare professionals accurately record and classify viral brain infections when the specific virus is identified or when it is a less common type.
Instructional Notations
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- encephalitis due to cytomegalovirus B25.8
- encephalitis due to herpesvirus NEC B10.0
- encephalitis due to herpesvirus [herpes simplex] B00.4
- encephalitis due to measles virus B05.0
- encephalitis due to mumps virus B26.2
- encephalitis due to poliomyelitis virus A80
- encephalitis due to zoster B02.0
- lymphocytic choriomeningitis A87.2
- myalgic encephalomyelitis G93.32
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Phlebovirus
A genus of the family BUNYAVIRIDAE comprising many viruses, most of which are transmitted by Phlebotomus flies and cause PHLEBOTOMUS FEVER. The type species is RIFT VALLEY FEVER VIRUS.
Rift Valley Fever
An acute infection caused by the RIFT VALLEY FEVER VIRUS, an RNA arthropod-borne virus, affecting domestic animals and humans. In animals, symptoms include HEPATITIS; abortion (ABORTION, VETERINARY); and DEATH. In humans, symptoms range from those of a flu-like disease to hemorrhagic fever, ENCEPHALITIS, or BLINDNESS.
Rift Valley fever virus
A mosquito-borne species of the PHLEBOVIRUS genus found in eastern, central, and southern Africa, producing massive hepatitis, abortion, and death in sheep, goats, cattle, and other animals. It also has caused disease in humans.
