Molecular detection and phylogenetic analysis of lumpy skin disease virus in Yunnan Province, China from 2019 to 2023.

The lumpy skin disease (LSD), caused by the lumpy skin disease virus (LSDV), represents an emerging infectious disease that poses substantial economic losses to the cattle industries in China. This study aimed to investigate the epidemiological characteristics of LSDV in Yunnan Province, Southwest China, from 2019 to 2023. A Taqman-probe-based real-time PCR (qPCR) assay was developed for the molecular detection of LSDV nucleotides. In total, 2495 samples were collected and tested using the established method. LSDV-positive samples were further analyzed by amplifying and sequencing the GPCR and p32 genes. In addition, Viral isolation was performed to explore the biological characterisitics of the isolate. The developed qPCR assay demonstrated high sensitivity, with a limit of detection of 4.83 copies/µL. Six samples (0.24%) tested positive for LSDV, all originating from skin scabs. Molecular and phylogenetic analyses of the GPCR and p32 genes revealed that these six LSDV strains were genetically related to strains previously reported from China, Russia, and Thailand. One LSDV strain, designated YUN-LSDV, was successfully isolated in primary sheep testicular (PST) cells; while the isolate exhibited insensitivity to Madin-Darby bovine kidney cells. Collectively, this study represents the first report on the epidemiological characteristics of LSDV in cattle in Yunnan Province and contributes to the development of effective prevention and control strategies for LSD.