Identification and genetic analysis of new ephemeroviruses in wild boars in China

Ephemeroviruses (EVs) are arthropod-borne rhabdoviruses and were isolated exclusively from cattle and haematophagous arthropods until two new ephemeroviruses were first identified from domestic pigs most recently. Here we report the identification of newer EVs in wild boar by meta-transcriptomic (MTT) sequencing. Further screening by specific RT-nPCR of tissue samples of 459 free-ranging wild boars collected between 2018 and 2023 from 26 provinces across China confirmed five positive wild boars in four provinces. Interestingly, two ticks especially collected from two positive wild boars were also EV positive. Finally, four complete genome sequences of wild boar ephemeroviruses (WbEVs) were obtained with two strains belonging to a new EV species, and the rest two falling into porcine ephemerovirus 2 (PoEV2) species identified from domestic pigs. Our study has further extended EV host range and demonstrated natural circulations of divergent EVs in wild boars, in which ticks may play roles. Biological implications of EV infection in wild boars should be interesting topics for future investigations.