Epidemic source analysis of peste des petits ruminants in Pseudois nay-aur in Helan Mountain,Ningxia,China
From 2018 to 2023,wild Pseudois nayaur were found to have died of unknown causes continuously in Helan Mountain National Nature Reserve of Ningxia,which was confirmed to be positive for peste des petits ruminants virus(PPRV)nucleic acid through anatomical sampling and real-time fluorescent RT-PCR detection.Vero cells were used to isolate some strains of PPRV,and RT-PCR was used to amplify the full-length fragments of PPRV F gene from diseased domestic sheep and wild animal samples in Ningxia.DNASTAR Lasergene and MEGA X were used to compare and an-alyze the PPRV F gene sequence and construct a phylogenetic tree to analyze its molecular genetic characteristics.The results show:the homology of F gene of PPRV strains infected by domestic sheep and Pseudois nayaur of Helan Moun-tain in different years in Ningxia was above 99%,among which the 2023 strain had the highest homology of 99.8%with that in January 2018 and 2019,and 99.6%with the PPR epidemic strains in 2014 and 2016 in Ningxia and China/XJYL/2013(KM091959.1)of Xinjiang.Genetic analysis showed that the PPRV of wild Pseudois nayaur and domestic sheep in Ningxia belonged to the central Asian branch of gene Ⅳ line.Therefore,it is speculated that the epidemic of PPR in Ningxia and neighboring provinces may have spread in the wild animals of Helan Mountain through different ways,and it is necessary to strengthen the surveillance of PPR and other wild animal diseases.
Helan Mountain in NingxiaPseudois nayaurPeste des petits ruminantsMolecular genetic characteristics