Table 1.
Clinical and biochemical characteristics of 171 patients suspected of having meningitis on admission
| Purulent meningitis of known aetiology (n = 31) | Purulent meningitis of unknown aetiology (n = 20) | Lymphocytic meningitis (n = 59) | Encephalitis (n = 11) | No CNS infection (n = 50) | |
| Female sex | 45% (14/31) | 50% (10/20) | 41% (24/59) | 45% (5/11) | 48% (24/50) |
| Age (in years) | 20 (10–53) (31/31) | 23 (7–30) (20/20) | 25 (17–31)‡ (59/59) | 55 (46–64) (11/11) | 28 (10–44) (50/50) |
| Underlying illness* | 23%† (7/31) | 10% (2/20) | 2% (1/59) | 0% (0/11) | 4% (2/50) |
| Body temperature (°C) | 38.8 (38.4–39.6)† (27/31) | 38.3 (38.0–39.2) (18/20) | 38.1 (37.7–38.7) (49/59) | 37.8 (37.1–38.9) (9/11) | 39 (37.5–39.6) (37/50) |
| Mean arterial pressure (mmHg) | 93 (87–117) (22/31) | 90 (79–106) (12/20) | 90 (82–100) (42/59) | 102 (86–115) (10/11) | 93 (77–103) (30/50) |
| Heart rate (beats/minute) | 113 (98–129)†‡ (20/31) | 90 (80–108) (16/20) | 88 (73–100) (44/59) | 80 (70–101) (10/11) | 100 (85–120) (30/50) |
| Septic shock | 16%† (5/31) | 0% (0/20) | 0% (0/59) | 0% (0/11) | 8% (4/50) |
| Back rigidity | 80%* (24/30) | 95%ठ(18/19) | 88%ठ(51/58) | 40% (4/10) | 57% (26/46) |
| Decreased consciousness | 66%*†§ (19/29) | 22%†‡ (4/18) | 0%‡ (0/57) | 91%§ (10/11) | 13% (6/46) |
| Assisted ventilation | 45%*†§ (14/31) | 0% (0/20) | 0% (0/59) | 20% (2/10) | 10% (5/50) |
| Steroid therapy | 35%*†§ (11/31) | 0% (0/20) | 0% (0/59) | 10% (1/10) | 0% (0/50) |
| Fatal outcome | 23%† (7/31) | 5% (1/20) | 0% (0/59) | 18% (2/11) | 4% (2/50) |
| Days in hospital (survivors) | 11 (9–15)†§ (24/24) | 9 (8–12)†§ (19/19) | 4 (2–5)‡ (59/59) | 12 (11–30)§ (9/9) | 4 (2–7) (48/48) |
| CSF WBC count (× 106 cells/l) | 3380 (767–6,528)*†‡§ (31/31) | 359 (128–1,066)‡§ (20/20) | 139 (61–366)§ (59/59) | 57 (13–102)§ (11/11) | 1 (1–2) (50/50) |
| CSF PMNs (× 106 cells/l) | 2,727 (398–5,404)*†‡§ (30/31) | 305 (112–600)†‡§ (20/20) | 25 (7–75)§ (56/59) | 5 (2–29)§ (9/11) | < 1 |
| CSF mononuclear (× 106 cells/l) | 248 (38–523)§ 30/31 | 16 (6–93)§ (20/20) | 74 (25–327)§ (56/59) | 79 (25–106)§ (9/11) | < 1 |
| CSF glucose (mmol/l) | 2.2 (0.6–3.5)†§ (30/31) | 3.3 (3.0–3.7)§ (17/20) | 3.3 (3.0–3.6)§ (56/59) | 3.1 (2.7–3.9) (10/11) | 3.7 (3.4–4.5) (48/50) |
| CSF/blood glucose ratio | 0.3 (0.1–0.5)*†§ (22/31) | 0.6 (0.4–0.7) (15/20) | 0.6 (0.5–0.7) (46/59) | 0.5 (0.3–0.7) (8/11) | 0.6 (0.6–0.8) (30/50) |
| CSF protein (g/l) | 1.9 (1.5–4.8)*†§ (30/31) | 0.7 (0.7–1.4)§ (20/20) | 0.7 (0.4–1.3)§ (54/59) | 1.1 (0.6–1.7)§ (11/11) | 0.3 (0.2–0.5) (47/50) |
| Blood WBC count (× 109 cells/l) | 21.7 (14.1–24.4)†‡§ (31/31) | 14.4 (8.3–16.8)† (20/20) | 8.8 (7.3–10.9) (59/59) | 7.4 (6.9–9.6) (9/11) | 9.0 (6.2–12.8) (48/50) |
| Blood PMNs (× 109 cells/L) | 17.1 (12.5–21.5)*†‡§ (30/31) | 10.9 (7.0–15.0)†§ (20/20) | 6.8 (5.3–8.5) (58/59) | 4.5 (4.1–9.2) (4/11) | 6.0 (4.5–9.6) (39/50) |
| Blood lymphocytes (× 109 cells/L) | 1.1 (0.7–1.5) (30/31) | 1.4 (1.1–1.8) (20/20) | 1.5 (1.0–1.9) (58/59) | 1.7 (0.8–2.1) (4/11) | 1.3 (0.8–2.1) (38/50) |
| Blood monocytes (× 109 cells/l) | 0.7 (0.4–1.0)† (30/31) | 0.6 (0.4–0.9) (20/20) | 0.4 (0.3–0.6) (58/59) | 0.6 (0.3–0.9) (4/11) | 0.4 (0.3–0.8) (38/50) |
| Platelets (× 109 cells/l) | 235 (166–286) (31/31) | 286 (215–370) (20/20) | 254 (210–310) (56/59) | 231 (174–351) (9/11) | 230 (168–275) (47/50) |
| Sodium (mmol/l) | 136 (135–138) (30/31) | 136 (133–139) (20/20) | 138 (136–140) (59/59) | 130 (127–140) (8/11) | 138 (136–141) (43/50) |
| Potassium (mmol/l) | 3.6 (3.3–3.9)† (29/31) | 3.8 (3.6–4.1) (19/20) | 3.9 (3.7–4.2) (59/59) | 4.0 (3.9–4.1) (7/11) | 3.9 (3.4–4.3) (44/50) |
| Creatinine (μmol/l) | 76 (54–85) (30/31) | 58 (46/72) (18/20) | 75 (55–85) (56/59) | 83 (73–100) (7/11) | 71 (49–87) (45/50) |
| Factors II, IIV and X | 0.57 (0.4–0.7)† (28/31) | 0.92 (0.7–1.0) (11/20) | 0.78 (0.7–1.0) (36/59) | 0.73 (0.6–1.0) (7/11) | 0.74 (0.5–0.9) (31/50) |
| Arterial PO2 (kPa) | 11.0 (9.0–13.0) (15/31) | 12.3 (10.7–13.8) (7/20) | 8.5 (7.8–11.5) (3/59) | 5.2 (1/11) | 12.7 (8.0–15.0) (6/50) |
| Positive blood culture | 62%*†‡§ (18/29) | 0% (0/20) | 0% (0/59) | 0% (0/10) | 6% (3/48) |
Values are expressed as percentage or median (interquartile range) (n/n evaluated). For continuous data Kruskal Wallis test with subsequent Mann-Whitney test was used; for categorical data Fisher's exact test was employed. When appropriate, correction for multiple comparisons with a Bonferroni coefficient of 10 was applied. *P < 0.05 versus purulent meningitis of unknown aetiology; †P < 0.05 versus lymphocytic meningitis; ‡P < 0.05 versus encephalitis; §P < 0.05 versus non-meningitis. aFor example, malignancy, diabetes, drug abuse or alcoholism. CSF, cerebrospinal fluid; PMN, polymorphonuclear leucocyte; PO2, partial oxygen tension; WBC, white blood cell.