Proportion of CSF samples with normal or abnormal clinical or laboratory findings in which virus was detected by PCR
| Symptom, sign, or laboratory investigation* | Finding present (%) | Finding absent (%) | Odds ratio (95% CI) | p Value |
|---|---|---|---|---|
| *Not all clinical or laboratory features were recorded for each patient; †odds ratio calculated by comparison of findings in <3 days group with subsequent groups. | ||||
| CSF, cerebrospinal fluid; EEG, electroencephalogram; NS, not significant; WCC, white cell count. | ||||
| Fever (⩾37.5°C) | 30/199 (15%) | 21/224 (9%) | 1.72 (0.94 to 3.15) | NS |
| Meningism | 14/75 (19%) | 41/408 (10%) | 2.05 (1.04 to 4.05) | 0.0498 |
| Headache | 27/160 (17%) | 15/225 (7%) | 2.84 (1.44 to 5.62) | 0.0027 |
| Rash | 8/50 (16%) | 46/429 (11%) | 1.59 (0.69 to 3.65) | NS |
| Focal neurology | 8/113 (7%) | 47/370 (13%) | 0.52 (0.24 to 1.16) | NS |
| Seizures | 13/127 (10%) | 41/352 (12%) | 0.86 (0.44 to 1.70) | NS |
| Encephalopathy | 14/139 (10%) | 36/313 (12%) | 0.86 (0.44 to 1.68) | NS |
| Immunosuppression | 11/71 (16%) | 44/410 (11%) | 1.53 (0.74 to 3.16) | NS |
| Abnormal CNS imaging | 14/161 (9%) | 21/194 (11%) | 0.78 (0.38 to 1.62) | NS |
| Abnormal EEG | 12/89 (14%) | 4/20 (20%) | 0.62 (0.17 to 2.24) | NS |
| Abnormal CSF WCC | 24/128 (19%) | 29/344 (8%) | 2.51 (1.38 to 4.55) | 0.0028 |
| Abnormal CSF protein | 23/132 (17%) | 25/311 (8%) | 2.41 (1.30 to 4.49) | 0.0062 |
| Delay between onset of symptoms and lumbar puncture† | ||||
| <3 days | 6/101 (6%) | |||
| 3 to <7 days | 19/99 (19%) | 0.270 (0.10 to 0.71) | 0.0088 | |
| 7 to <14 days | 15/90 (16%) | 0.32 (0.11 to 0.87) | 0.0329 | |
| ⩾14 days | 2/92 (2%) | 2.84 (0.54 to 14.94) | NS | |