Japanese encephalitis virus (JEV) is a mosquito-borne zoonotic flavivirus causing severe neurological disease across Asia, and genotype V (GV) is now predominant in Korea. Despite frequent detection of GV in mosquitoes, human-derived complete genome data remain scarce. To elucidate the molecular and antigenic characteristics of human GV infections, cerebrospinal fluid samples from unvaccinated patients positive for JEV RNA during 2018–2023 were subjected to virus isolation in LLC-MK2 cells (rhesus monkey kidney-derived epithelial cell line). Three human GV isolates (K18P80, K23P84, K23P88) were successfully obtained and their complete open reading frames (~10.3 kb) sequenced. Phylogenetic analysis with representative JEV strains (GI–GV) revealed that these isolates form a distinct lineage, clustering into two domestic clades (Clade I and II), suggesting endemic circulation and local evolution in Korea. Sequence identities with GIII-based vaccine strains were low (79% nucleotide, 91.1% amino acid), with notable divergence in nonstructural regions. Three consistent E protein substitutions (Q52E, S156T, D292E) near antigenic epitopes indicate possible immune escape. Additional clade-defining substitutions in NS3 (L31F) and NS5 (K269R, M330I) were shared with mosquito isolates, supporting human–vector molecular continuity. These findings provide fundamental genomic evidence of human JEV GV in Korea and highlight the need for genotype-specific surveillance and next-generation vaccine evaluation.

Lee YJ, et al. J Korean Med Sci. 2027 Feb;42:e19. https://doi.org/10.3346/jkms.2027.42.e19

이예지, 조승례, 이선영, 전소연, 이덕용, 김희만, 신현일, 권정란, 여상구, 주혁. Public Health Weekly Report 2026;19:1651-66. https://doi.org/10.56786/PHWR.2026.19.39.1

견미랑, 김은지, 라부미, 이예지, 조승례, 박선환, 박은서, 이덕용, 주혁. Public Health Weekly Report 2026;19:1052-68. https://doi.org/10.56786/PHWR.2026.19.26.2