Identification and genotyping of a new subtype of bovine viral diarrhea virus 1 isolated from cattle with diarrhea.

In 2019, diarrhea cases occurred on cattle farms in Qionglai and Guang'an, Sichuan Province. Two out of 20 (10%) serum and nasal swab samples were positive when tested using a bovine viral diarrhea virus (BVDV) antigen-capture ELISA kit. Two non-cytopathic strains of BVDV were isolated and named QL1903 and GA190608, respectively. The nucleotide sequences of the genomes of the two isolates were 89.52% identical. Phylogenetic analysis based on the 5'-UTR sequence revealed that the BVDV isolate QL1903 belonged to BVDV subtype 1b, whereas isolate GA190608 clustered with strains HN1814, EN-19, and BJ09_26 in a separate branch, which has tentatively been classified as a new genetic subtype, "1v".