Table 1.
Clinical features of study population by cause of the central nervous system (CNS) infection.
| All CNS Infections | All Confirmed Bacterial CNS Infections | All Confirmed Aseptic CNS Infections | All CNS Infections of Unknown Cause | Aseptic CNS Infections | Unknown Cause of CNS Infection | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| p * | Enteroviruses | Tick Borne Encephalitis Virus | Borrelia burgdorferi | Varicella Zoster Virus | Probably Bacterial CNS Infections | Probably Viral CNS Infections | p ** | |||||
| Year | ||||||||||||
| 2015; n (%) | 76 (100%) | 3 (4%) | 67 (88%) | 6 (8%) | - | 54 (71%) | 7 (9%) | 3 (4%) | 3 (4%) | 0 (0%) | 6 (8%) | - |
| 2016; n (%) | 54 (100%) | 6 (11%) | 35 (65%) | 13 (24%) | - | 22 (41%) | 4 (7%) | 8 (15%) | 0 | 3 (6%) | 10 (18%) | - |
| 2017; n (%) | 72 (100%) | 5 (7%) | 60 (83%) | 7 (10%) | - | 35 (49%) | 14 (19%) | 7 (10%) | 3 (4%) | 5 (7%) | 2 (3%) | - |
| 2018; n (%) | 64 (100%) | 4 (6%) | 54 (84.5%) | 6 (9.5%) | - | 38 (59%) | 8 (13%) | 6 (9.5%) | 2 (3%) | 2 (3%) | 4 (6%) | - |
| 2019; n (%) | 108 (100%) | 8 (7.5%) | 89 (82.5%) | 11 (10%) | - | 75 (69%) | 9 (8%) | 2 (2%) | 2 (2%) | 1 (1%) | 10 (10%) | - |
| Total; n (%) | 374 (100%) | 26 (7%) | 305 (82%) | 43 (11%) | - | 224 (60%) | 42 (11%) | 26 (7%) | 10 (3%) | 11 (3%) | 32 (9%) | - |
| Gender | ||||||||||||
| Female; n (%) | 137 (100%) | 11 (8%) | 107 (78%) | 19 (14%) | NS | 77 (56%) | 16 (12%) | 9 (7%) | 5 (4%) | 5 (4%) | 14 (10%) | NS |
| Male; n (%) | 237 (100%) | 15 (6%) | 198 (84%) | 24 (10%) | NS | 147 (62%) | 26 (11%) | 17 (7%) | 5 (2%) | 6 (3%) | 18 (8%) | NS |
| Age (years) | 8.21 (4.93–13.04) | 0.83 (0.15–5.41) | 8.8 (5.6–13.7) | 6.52 (3–11.39) | <0.001 | 8.1 (5.4–12.7) 2 | 11.9 (8.5–16.6) 1 | 10.02 (7.42–13.7) | 9.1 (4.2–15.6) | 4.47 (1.82–5.92) | 8.32 (4.29–14.08) | 0.02 |
| Age groups | ||||||||||||
| <1; n (%) | 22 (100%) | 13 (59%) | 3 (14%) | 6 (27%) | <0.001 | 3 (14%) | 0 | 0 | 0 | 2 (9%) | 4 (18%) | NS |
| 1–3; n (%) | 36 (100%) | 6 (17%) | 25 (69%) | 5 (14%) | 0.02 | 18 (50%) | 0 | 3 (8%) | 2 (6%) | 2 (6%) | 3 (14%) | NS |
| 4–6; n (%) | 102 (100%) | 2 (2%) | 87 (85%) | 13 (13%) | 0.02 | 74 (73%) | 8 (8%) | 3 (3%) | 2 (2%) | 7 (7%) | 6 (6%) | 0.009 |
| 7–13; n (%) | 136 (100%) | 4 (3%) | 121 (89%) | 11 (8%) | 0.02 | 89 (65%) | 14 (10%) | 14 (10%) | 3 (2%) | 0 (0%) | 11 (8%) | 0.04 |
| 14–17; n (%) | 78 (100%) | 1 (1%) | 69 (88%) | 8 (10%) | 0.02 | 40 (51%) | 20 (26%) | 6 (7%) | 3 (4%) | 0 (0%) | 8 (10%) | NS |
| Clinical presentation | ||||||||||||
| Meningitis; n (%) | 332 (100%) | 21 (6%) | 280 (84%) | 31 (10%) | NS | 219 (66%) 2,3 | 29 (9%) 1,3 | 26 (8%) 1,2 | 5 (2%) | 9 (3%) | 22 (7%) | NS |
| Encephalitis; n (%) | 42 (100%) | 5 (12%) | 25 (59%) | 12 (29%) | NS | 5 (12%) 2,3 | 13 (31%) 1,3 | 01,2 | 5 (12%) | 2 (5%) | 10 (24%) | NS |
| Signs and symptoms | ||||||||||||
| Headaches | 333/374 (89%) | 8/13 (62%) | 291/305 (95%) | 34/43 (79%) | <0.001 | 221/224 (98%) | 40/42 (95%) | 19/26 (73%) | 9/10 (90%) | 9/11 (82%) | 25/32 (78%) | NS |
| Fever | 314/374 (84%) | 25/26 (96%) | 260/305 (85%) | 29/43 (67%) | NS | 203/224 (91%) 3 | 41/42 (98%) 3 | 6/26 (23%) 1,2 | 7/10 (70%) | 10/11 (91%) | 19/32 (59%) | NS |
| Vomiting | 251/373 (67%) | 14/26 (54%) | 212/305 (69%) | 25/42 (59%) | NS | 170/224 (76%) 3 | 24/42 (57%) | 7/26 (27%) 1,4 | 9/10 (90%) 3 | 7/10 (70%) | 18/32 (56%) | NS |
| Photophobia | 73/373 (20%) | 8/26 (31%) | 55/305 (18%) | 10/42 (24%) | NS | 42/224 (19%) | 7/42 (17%) | 2/26 (8%) | 3/10 (30%) | 3/10 (30%) | 7/32 (22%) | NS |
| Neck stiffness | 255/374 (68%) | 13/26 (50%) | 220/305 (72%) | 22/43 (515) | 0.02 | 164/224 (73%) | 32/42 (76%) | 14/26 (54%) | 8/10 (80%) | 7/11 (64%) | 15/32 (47%) | NS |
| Tremor | 18/374 (5%) | 1/26 (4%) | 13/305 (4%) | 4/43 (9%) | NS | 3/224 (1%) | 6/42 (14%) | 0/26 | 3/10 (30%) | 0/11 (0%) | 4/32 (13%) | NS |
| Seizures | 15/374 (4%) | 3/26 (12%) | 5/305 (2%) | 7/43 (16%) | 0.02 | 2/224 (1%) | 2/42 (5%) | 0/26 | 0/10 | 0/11 (0%) | 7/32 (22%) | NS |
| Facial nerve palsy | 23/374 (6%) | 0/26 (0%) | 21/305 (7%) | 2/43 (5%) | NS | 0/224 3 | 2/42 (5%) 3 | 19/26 (73%) 1,2,4 | 0/10 3 | 0/11 (0%) | 2/32 (6%) | NS |
| Cognitive dysfunction | 31/362 (9%) | 8/15 (53%) | 16/305 (5%) | 7/43 (16%) | <0.001 | 3/224 (2%) | 10/42 (24%) | 0/25 | 1/10 (10%) | 2/11 (18%) | 5/32 (16%) | NS |
| Altered level of consciousness | 66/374 (18%) | 20/26 (77%) | 31/305 (10%) | 15/43% (35%) | <0.001 | 8/224 (4%) 2 | 20/42 (48%) 1,3 | 0/252 | 2/10 (20%) | 4/11 (18%) | 11/32 (34%) | NS |
| Length of hospital stay (days) | 10 (7–16) | 24 (16–34) | 8 (7–13) | 15 (13–19) | <0.001 | 7 (7–9) 2,3,4 | 16 (13–18)1 | 23 (21–25) 1 | 23 (15–24)1 | 17 (14–21) | 14 (12.5–18.5) | NS |
| Antibiotics | 100/374 (27%) | 26/26 (100%) | 50/305 (16%) | 24/43 (56%) | <0.001 | 9/224 (4%) | 10/42 (24%) | 26/26 (100%) | 2/10 (20%) | 11/11 (100%) | 13/32 (41%) | 0.003 |
| Acyclovir | 26 (7%) | 0/26 (0%) | 17/305 (6%) | 9/43 (21%) | NS | 1 (<1%) | 4 (10%) | 0 (0%) | 10 (100%) | 0/11 (0%) | 9/32 (28%) | NS |
| CSF cells (/µL) | 144 (48–385) | 2347 (288–5800) | 136 (49–313) | 126 (30–305) | <0.001 | 135 (46.5–357.5) | 87.5 (50–178) | 196.5 (62–389) | 591 (144–930) | 444 (14–1290) | 120.5 (42–220) | NS |
| CSF protein (mg/dL) | 35 (26–57) | 134 (52–283.5) | 35 (26–53) | 37 (26–72) | <0.001 | 32.5 (25–43.5) 2,3 | 44 (31–61) 1 | 59.4 (34–83) 1 | 81 (20–170) | 36 (21–83) | 37 (26–72) | NS |
| CSF lymphocytes (%) | 63 (30–83) | 14 (8–21) | 68 (37–84) | 74 (23–90) | <0.001 | 60 (32–80) 3,4 | 71 (35.5–86) 3,4 | 88.5 (82–94) 1,2 | 91.5 (83–98) 1,2 | 15 (5–55) | 78 (34–92) | 0.009 |
| CSF neutrophils (%) | 23 (6–58) | 79 (63–91) | 20 (6–52.5) | 8.5 (3–73) | <0.001 | 26 (8–57) 3,4 | 17.5 (7–53.5) 3 | 3 (1–9) 1,2 | 3 (0–11) 1 | 82 (30–89) | 6.5 (2–46) | 0.008 |
| CSF monocytes (%) | 7 (2–12) | 5.5 (1.5–15) | 7 (2–12) | 6 (1–14) | NS | 7 (2–13) | 7 (3–11) | 6 (3–11) | 3.5 (2–6) | 5 (0–8) | 6 (2–14) | NS |
| CRP (mg/L) | 4.16 (1.2–14.17) | 154 (93.32–228.25) | 3.36 (1.1–9.46) | 7.37 (1.4–58.69) | <0.001 | 3.79 (1.24–10.88) 3,4 | 5.96 (2.48–12) 3,4 | 0.65 (0.34–1.51) 1,2 | 0.28 (0.15–1.73) 1,2 | 214.42 (59.77–306) | 3.21 (0.8–11.46) | <0.001 |
| CRP > 10 mg/L | 117/372 (31%) | 24/25 (96%) | 74/304 (24%) | 19/43 (44%) | <0.001 | 57 (25%) | 14 (33%) | 2 (8%) | 0 | 11/11 (100%) | 8/32 (25%) | <0.001 |
| WBC (×109 cells/L) | 9.22 (6.94–12.4) | 19.65 (10.94–25.8) | 8.8 (6.89–11.34) | 12.1 (7.6–17.71) | <0.001 | 8.8 (6.94–11.07) 2,3 | 11.25 (8.44–15.08) 1,3,4 | 6.59 (5.8–8.8) 1,2 | 7.23 (4.97–8.55) 2 | 23.7 (17.17–35.6) | 9.7 (6.89–12.84) | <0.001 |
| Blood Lymphocytes (%) | 25 (15–36) | 21 (10–37) | 25.8 (16.7–36) | 24 (12.4–31.4) | NS | 27.15 (17.65–36.5) 2 | 15 (11–21) 1,2,4 | 32.85 (25.9–41.1) 2 | 32.6 (26.2–51.9) 2 | 11 (6–24) | 25.5 (13–37.6) | NS |
| Blood neutrophils (%) | 63 (51.5–76.8) | 66.55 (56–83) | 62 (51.2–74.9) | 68.5 (58.1–81) | NS | 60.9 (50.7–72.8) 2 | 75.8 (66.7–82) 1,3,4 | 50.25 (45–61.3) 2 | 51.5 (30.8–62.6) 2 | 81 (68.5–88) | 64.6 (53.9–79) | NS |
Continuous variables are presented as medians (IQR). Categorical variables are shown as frequencies. *—p-value for comparing aseptic and bacterial infections of the CNS; **—p-value for comparing probably bacterial and probably viral infections of the CNS; 1 p < 0.01 vs. enteroviral infection of the CNS; 2 p < 0.01 vs. tick-borne encephalitis; 3 p < 0.01 vs. Lyme neuroborreliosis; 4 p < 0.01 vs. CNS infection cause by varicella zoster virus. The differences between aseptic and bacterial infections of the CNS and between probably bacterial and probably viral infections of the CNS were analyzed with the Fisher’s exact test (categorical variables) or the Mann-Whitney U test (continuous variables). The differences between enteroviral infections of the CNS, tick-borne encephalitis, Lyme neuroborreliosis, and CNS infections caused by varicella zoster virus were analyzed by the Kruskal-Wallis test.