Molecular characterization of lumpy skin disease virus in the cattle population of District Lower Chitral, Khyber Pakhtunkhwa, Pakistan

Lumpy skin disease (LSD) is a transboundary viral infection of cattle caused by the lumpy skin disease virus (LSDV), a member of the Poxviridae family in genus Capripox. In Pakistan, after its first outbreak in 2021, the disease caused significant financial damage to the livestock sector. The current study was designed to investigate LSDV and its histopathological lesions in the LSDV infected cattle population of the Lower Chitral district of Khyber Pakhtunkhwa, Pakistan. Overall, 384 samples were collected, including nasal swabs, blood, and skin nodules from LSDV suspected cattle. These samples were subjected to Polymerase Chain Reaction (PCR) by targeting the p32 and ORF036 coding regions in the virus. Out of 384 samples, 71 were positive for both coding regions. The phylogenetic analysis revealed that virus strains from neighboring countries shared a common cluster with PQ067260 from Chitral, indicating the close genetic relationship between them. Seasonal analysis showed the highest prevalence of LSDV in summer (23%). Additionally, our research identified that the virus is more likely to infect females (32%) than males, animals younger than one year (25%) than older than one year, and cross cattle breeds (22%) than other breeds. Our results also found variations in disease prevalence across different regions of Chitral. Subsequent SPSS analysis demonstrated that gender (< 0.0001), age (0.0002), season (0.0004), and breed (< 0.0001) had a significant impact on the prevalence of the disease. Histopathology indicated presence of eosinophils, vacuolar degeneration, necrosis, and leukocytic infiltration, in diseased tissues. Further research needs to be conducted on the isolation of the field virus and local vaccine development to control this highly contagious and economically important viral disease in the country.