Recent advances in techniques used in the diagnosis of lumpy skin disease: a review

Lumpy skin disease (LSD) is a viral disease that affects livestock and is caused by the lumpy skin disease virus (LSDV). An outbreak of LSD in any country can lead to acute economic damage for livestock owners. The significance of prompt and accurate diagnosis in managing this viral disease cannot be overstated. Here we review the techniques used for the detection of LSDV and its application in the diagnosis of LSD. Nucleic acid detection, including conventional PCR, quantitative real-time PCR, and high-resolution melting assays, is used most often because of its strong sensitivity and specificity. These methods are expensive and require skilled personnel. Faster but less-sensitive tests include immunoassay formats, such as ELISA, virus neutralization test, immunoperoxidase monolayer assay, and indirect fluorescent antibody test. Various serologic and molecular tests are used to distinguish virulent strains of LSDV from vaccine strains. As well, sheeppox virus, goatpox virus, and LSDV share 96-97% genetic resemblance and must be differentiated reliably. New techniques, such as loop-mediated isothermal amplification, recombinase polymerase amplification, fluorescence assays based on CRISPR-Cas12a, nanopore sequencing, and lateral flow immunoassays, provide greater sensitivity in detecting lower quantities of viral nucleic acids, making them ideal for quick and economical tests in the field.