Compared with peak EAE, WNV encephalitis and ECM in C57Bl/6 WT mice CNS Il17a expression was significantly higher in the GF/IL17A mice (peak EAE: 10.6 ± 1.8, WNV 7.8 ± 4.6, ECM: 8.8 ± 5.1, for all p < 0.0001 compared to GF/IL17 mice). This evidence concerns the gene IL17A and encephalitis.