However, the isolation of the genotype 5 JEV strain in South Korea in 2015 was derived from a patient’s recovery-phase cerebrospinal fluid specimen; (5) Considering that using the method of detecting IgM antibodies for JEV infection is challenging when dealing with cases caused by genotype 4 and genotype 5 JEV, including JEV nucleic acid testing as a routine pathogen detection procedure for patients with viral encephalitis during mosquito season is recommended. Here, CD40LG is linked to viral encephalitis.