Dr. Peter Windsor and Dr. Richard Whittington published a review article on ovine Johne’s disease (OJD) control in Australia. This excellent review article appears in the journal Animals and is Open Access. It nicely reviews the pathogenesis and control of paratuberculosis in sheep, but the most interesting part of the article addresses the top 10 subjects of misinformation about OJD in Australia.
OJD is no longer the serious animal health issue that it was for many Australian rural communities a decade and a half ago. Despite declining OJD prevalence as determined by abattoir surveillance, the disease continues to spread, with OJD extension programs required to continually address the misinformation promulgated by some disaffected producers as new areas have become affected. Improved regional and on-farm biosecurity, including the introduction of a risk-based trading system, may have contributed to improved attitudes to OJD control, although attitudinal differences between OJD endemic areas and where the disease is not well established remain. Declines in on-farm OJD prevalence are almost certainly attributable to the widespread uptake of vaccination programs, although encouraging the ongoing use of vaccination to prevent recrudescence and improved biosecurity when mortalities disappear, remains challenging. Vaccination has provided a robust strategy for managing OJD and contributed significantly to the health of Australian sheep and the lives of producers with affected properties. As vaccination offers a pathway to reduce the risk of MAP infection entering the human food chain from small ruminant products, it should be more widely adopted globally, accompanied by research efforts to improve efficacy and importantly, the safety of vaccination to both operators and livestock.
Comment: Not all countries, such as the U.S., have access to the vaccine for paratuberculosis that is used in Australia. For pictures of sheep before and after developing clinical Johne’s disease can be found here.