Enhancing Australia’s serodiagnostic and surveillance capabilities for sheeppox, goatpox and lumpy skin disease

Summary

​Capripoxviruses cause sheeppox, goatpox, and lumpy skin disease of cattle, which are the most serious poxvirus diseases of production animals. Although the risk of these diseases entering Australia is considered low, the potential economic impact of an incursion would be considerable. There are currently no validated, high-throughput antibody detection tools available for undertaking post-outbreak surveillance and re-establishing freedom from disease, which is the primary factor that would mitigate the economic impact to the livestock industries in the event of an outbreak. To enhance diagnostic capability and preparedness eight antibody detection ELISA tests, based on recently discovered immunodominant viral antigens, were developed. Of the three assays that showed the most promise, one had a superior ability to differentiate between capripoxvirus infected and uninfected sheep, goats, and cattle, with diagnostic sensitivity and specificity ranging between 98–100%, but it was unable to detect antibodies reliably in vaccinated animals. No cross-reactivity with antibodies against orf or bovine papular stomatitis viruses was detected. Subject to ongoing evaluation to determine assay reproducibility, the ELISA offers the prospect of a reliable and standardised high-throughput serodiagnostic capability to support post-outbreak surveillance and proof of freedom testing, without the requirement for infectious reagents.