Chapter I
Certain infectious and parasitic diseases
(A00-B99)

Viral infections of the central nervous system
(A80-A89)

Excludes: sequelae of:
· poliomyelitis ( B91 )
· viral encephalitis ( B94.1 )

A80 Acute poliomyelitis
A80.0 Acute paralytic poliomyelitis, vaccine-associated
A80.1 Acute paralytic poliomyelitis, wild virus, imported
A80.2 Acute paralytic poliomyelitis, wild virus, indigenous
A80.3 Acute paralytic poliomyelitis, other and unspecified
A80.4 Acute nonparalytic poliomyelitis
A80.9 Acute poliomyelitis, unspecified

A81 Atypical virus infections of central nervous system
Includes: prion diseases of the central nervous system
A81.0 Creutzfeldt-Jakob disease
Subacute spongiform encephalopathy
A81.1 Subacute sclerosing panencephalitis
Dawson's inclusion body encephalitis
Van Bogaert's sclerosing leukoencephalopathy
A81.2 Progressive multifocal leukoencephalopathy
Multifocal leukoencephalopathy NOS
A81.8 Other atypical virus infections of central nervous system
Kuru
A81.9 Atypical virus infection of central nervous system, unspecified
Prion disease of central nervous system NOS

A82 Rabies
A82.0 Sylvatic rabies
A82.1 Urban rabies
A82.9 Rabies, unspecified

A83 Mosquito-borne viral encephalitis
Includes: mosquito-borne viral meningoencephalitis
Excludes: Venezuelan equine encephalitis ( A92.2 )
A83.0 Japanese encephalitis
A83.1 Western equine encephalitis
A83.2 Eastern equine encephalitis
A83.3 St Louis encephalitis
A83.4 Australian encephalitis
Kunjin virus disease
A83.5 California encephalitis
California meningoencephalitis
La Crosse encephalitis
A83.6 Rocio virus disease
A83.8 Other mosquito-borne viral encephalitis
A83.9 Mosquito-borne viral encephalitis, unspecified

A84 Tick-borne viral encephalitis
Includes: tick-borne viral meningoencephalitis
A84.0 Far Eastern tick-borne encephalitis [Russian spring-summer encephalitis]
A84.1 Central European tick-borne encephalitis
A84.8 Other tick-borne viral encephalitis
Louping ill
Powassan virus disease
A84.9 Tick-borne viral encephalitis, unspecified

A85 Other viral encephalitis, not elsewhere classified
Includes: specified viral:
· encephalomyelitis NEC
· meningoencephalitis NEC
Excludes: benign myalgic encephalomyelitis ( G93.3 )
encephalitis due to:
· herpesvirus [herpes simplex] ( B00.4 )
· measles virus ( B05.0 )
· mumps virus ( B26.2 )
· poliomyelitis virus ( A80.- )
· zoster ( B02.0 )
lymphocytic choriomeningitis ( A87.2 )
A85.0+ Enteroviral encephalitis ( G05.1* )
Enteroviral encephalomyelitis
A85.1+ Adenoviral encephalitis ( G05.1* )
Adenoviral meningoencephalitis
A85.2 Arthropod-borne viral encephalitis, unspecified
A85.8 Other specified viral encephalitis
Encephalitis lethargica
Von Economo-Cruchet disease

A86 Unspecified viral encephalitis
Viral:
· encephalomyelitis NOS
· meningoencephalitis NOS

A87 Viral meningitis
Excludes: meningitis due to:
· herpesvirus [herpes simplex] ( B00.3 )
· measles virus ( B05.1 )
· mumps virus ( B26.1 )
· poliomyelitis virus ( A80.- )
· zoster ( B02.1 )
A87.0+ Enteroviral meningitis ( G02.0* )
Coxsackievirus meningitis
Echovirus meningitis
A87.1+ Adenoviral meningitis ( G02.0* )
A87.2 Lymphocytic choriomeningitis
Lymphocytic meningoencephalitis
A87.8 Other viral meningitis
A87.9 Viral meningitis, unspecified

A88 Other viral infections of central nervous system, not elsewhere classified
Excludes: viral:
· encephalitis NOS ( A86 )
· meningitis NOS ( A87.9 )
A88.0 Enteroviral exanthematous fever [Boston exanthem]
A88.1 Epidemic vertigo
A88.8 Other specified viral infections of central nervous system

A89 Unspecified viral infection of central nervous system