Rapid detection of contagious ecthyma by loop-mediated isothermal amplification and epidemiology in Jilin Province China

The aim of this experiment was to develop a loop-mediated isothermal amplification (LAMP)assay and to research the recent epidemiology of contagious ecthyma in Jilin Province,China, using the assay. A LAMP assay targeting a highly conserved region of the F1L genewas developed to detect contagious ecthyma virus (CEV). Three hundred and sixty-five casesfrom 64 flocks in 9 different areas of Jilin Province, China, from 2011 to 2014 weretested using the LAMP assay. The results showed that the sensitivity of the LAMP assay was100 copies of the standard plasmid, which is 100-fold higher than the sensitivity of PCR.No cross-reactivity was observed with capripoxvirus, fowlpox virus, foot-and-mouth diseasevirus serotype O, foot-and-mouth disease virus serotype Asia I and bluetongue virus. Theaverage positive rate was 19.73% (72/365), and the positive rate was highest in lambs aged1–6 months. Our results demonstrated that CEV infection was very widespread in the flocksof Jilin Province and that the LAMP assay allows for easy, rapid, accurate and sensitivedetection of CEV infection.