Diagnostic utility of intranodular saline lavage in TaqMan probe-based real-time PCR diagnosis of lumpy skin disease

Lumpy skin disease (LSD), caused by the poxvirus lumpy skin disease virus has entered India, causing serious economic consequences for the Indian dairy sector. To evaluate the diagnostic value of intranodular saline lavage in the identification of LSD-infected animals, skin nodule tissue biopsy, intranodular saline lavage, whole blood, and nasal swab specimens were collected simultaneously from LSD-symptomatic animals. TaqMan probe-based real-time PCR was performed targeting the EEV glycoprotein gene (LSDV126) and the results were compared. qPCR analysis could detect LSDV in all the skin nodule tissue biopsy and intranodular saline lavage. The mean cycle threshold (Cq) values of skin nodule tissue biopsy samples (23.94 ± 2.97) were also comparable with intranodular saline lavage (25.23 ± 2.41) samples. Whole blood and nasal swabs have an extremely poor detection rate for PCR-based viral detection.Our findings demonstrate that intranodular saline lavage is an excellent alternative specimen for the detection of LSDV. Taking into consideration, the simplicity of specimen collection, intranodular saline lavage could be adopted in field conditions for accurate LSDV surveillance testing.