Classification of CNS viral infections using clinical and laboratory criteria*
| *Classification adapted from Jeffery et al.9 |
| Likely CNS viral infection (i and/or ii): |
| i. Raised CSF white cell count (defined by age group) accompanied by one or more of the following: meningism, headache, or fever (⩾37.5°C) (with no other explanation) |
| ii. Altered level of consciousness or focal neurological signs accompanied by fever (⩾37.5°C) or headache (with no other explanation) |
| Possible CNS viral infection: |
| Attending physician’s final diagnosis of a viral CNS infection with any combination of signs or symptoms |
| Unlikely CNS viral infection (one of the following): |
| i. Another definite diagnosis (for example, multiple sclerosis or bacterial meningitis) |
| ii. Non-specific diagnosis (for example, febrile convulsion where the clinical or laboratory features were not consistent with the above categories) |
| iii. No definite diagnosis (for example, fever of unknown cause where the clinical or laboratory features were not consistent with the above categories) |