GFAP and viral encephalitis: The median value of GFAP was 390 ng/l (IQR 324–536) for the patients with encephalitis and 279 ng/l (211–403) for the controls (Fig. 1b) and the median value of S100 was 0.66 μg/l (0.52–0.86) for the patients with encephalitis and 0.56 μg/l (0.45–0.71) for the controls (Fig. 1c).