Volume 15, Number 9—September 2009
Research
Etiology of Encephalitis in Australia, 1990–2007
Table
Encephalitis-associated conditions with ICD-9-CM and ICD-10-AM codes most frequently used for primary encephalitis discharge diagnoses, New South Wales, Australia, 1990–2007*
Primary discharge diagnosis ICD code (ICD-9; ICD-10) | No. hospitalizations (% of total) |
---|---|
All hospitalizations |
5,926 (100) |
Known pathogens | 1,800 (30.6) |
Herpes viral encephalitis (54.3; B00.4) | 763 (12.9) |
Varicella encephalitis (52.0; B01.1) | 226 (3.8) |
Toxoplasma meningoencephalitis (130.0; B58.2 ) | 221(3.7) |
Acute disseminated encephalitis (G04.0 in ICD-10) | 136 (2.3) |
Zoster encephalitis (B02.0 in ICD-10) | 105 (1.8) |
Subacute sclerosing panencephalitis (46.2; A81.1) | 79 (1.3) |
Other specified non–arthropod-borne viral diseases of the central nervous system (49.8; A85.8) | 71 (1.2) |
Enteroviral encephalitis (A85.0 in ICD-10) | 49 (0.8) |
Listerial meningitis and meningoencephalitis (A32.1 in ICD 10) | 28 (0.5) |
Encephalitis, myelitis, and encephalomyelitis –postinfectious encephalitis (323.6 in ICD-9) | 18 (0.3) |
Measles encephalitis (55.0 in ICD 9) | 15 (0.3) |
Encephalitis, myelitis, and encephalomyelitis –encephalitis in viral diseases classified elsewhere (323.0 in ICD 9) | 10 (0.2) |
Rubella with neurologic complications –encephalomyelitis due to rubella (56.01 in ICD-9) | 8 (0.1) |
Meningococcal infection –meningococcal encephalitis (36.1 in ICD-9) | 7 (0.1) |
Viral encephalitis transmitted by other and unspecified arthropods (64 in ICD-9) | 7 (0.1) |
Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified (G04.2 in ICD-10) | 7 (0.1) |
Mumps –mumps encephalitis (72.2 in ICD-9) | 6 (0.1) |
Other known pathogen codes (24 codes) |
44 (0.7) |
Unknown pathogens | 4,126 (69.6) |
Unspecified non–arthropod-borne viral diseases of the central nervous system or unspecified viral encephalitis (49.9; A86) | 2,218 (37.4) |
Encephalitis, myelitis, and encephalomyelitis –unspecified cause of encephalitis (323.9; G04.9) | 1,648 (28.8) |
Encephalitis, myelitis, and encephalomyelitis –other cause of encephalitis (323.8; G04.8) | 260 (4.4) |
*ICD-9-CM, International Classification of Diseases, 9th Revision, Clinical Modification; ICD-10-AM, International Classification of Diseases, 10th Revision, Australian Modification.