Abstract

Congress established the National Academy of Sciences (NAS) in 1863 to provide expert scientific and technical advice to the government, and the [sic]. The National Research Council (NRC) was organized in 1916 ais the working arm of the National Academy of Sciences and the National Academy of Engineering. At the request of a government agency, Congress, or other institution, the NRC conducts studies specifically designed to address unresolved or controversial questions that have important bearing on policy decisions. Following review and acceptance of a study request, the NRC convenes a committee of experts to address the study charge. Committee members are chosen for their relevant expertise, as well as their freedom from conflicts of interest, and must be approved by an NRC review panel. This selection process helps to ensure a credible and well-balanced study process and final report.

In August of 2001, the NRC Board on Agriculture and Natural Resources convened the Committee on the Diagnosis and Control of Johne’s Disease to address growing concern over the apparent increase in prevalence of Johne’s disease, the lack of national coordination of control programs, and the potential for public health ramifications. The charge of the committee was to 1) provide a review and synthesis of the information on diagnostic techniques, modes of transmission, clinical expression, global prevalence, and potential animal and human health implications of Johne’s disease (JD) in domestic and wild ruminants; 2) evaluate current JD control and prevention programs; 3) provide policy recommendations for JD identification, monitoring, and management strategies applicable to US livestock herds; 4) conduct an objective, critical assessment and summary of the state of knowledge of the relationship between JD in ruminants and Crohn’s disease in humans; and 5) provide recommendations for future research priorities and mechanisms to facilitate control and prevention of the disease.

Committee members included Sheldon Brown, MD, William Davis, PhD, John Gay, DVM, PhD, Ralph Giannella, MD, Murray Hines II, DVM, PhD, Lawrence Hutchinson, DVM, Will Hueston, DVM, PhD, and Bruce Rideout, DVM, PhD (Chair). The committee met twice in Washington D.C., and once in Hershey, Pennsylvania in conjunction with the annual meeting of the United States Animal Health Association. The latter meeting included a public workshop, where the committee had an opportunity to hear from a number of experts on Johne’s disease and from a leading Crohn’s disease patient advocacy group. At its final meeting, the committee received an update on research into the link between Mycobacterium avium subsp. paratuberculosis (MAP) and Crohn’s disease, and a progress report on the Map genome project at the National Animal Disease Laboratory.

The report represents the committee’s review and synthesis of the literature, evaluation of current control programs, assessment of the evidence for a link between MAP and Crohn’s disease, and its resulting conclusions and recommendations. Much of the emphasis in the report is on knowledge and control of JD in dairy cattle. This emphasis is difficult to avoid, as most of the published research, diagnostic test development, epidemiology, and control efforts have focused on dairy cattle. Nevertheless, the committee also evaluated the significance of JD in wildlife and zoo animals. Since JD control is becoming a major focus for USDA-APHIS, it will be important for the zoo and wildlife community to re-evaluate its own JD surveillance and control efforts. If a causal association is established between MAP and Crohn’s disease, JD control will become an important public health issue, which will significantly impact zoo animal management. Only a small minority of zoos is conducting routine surveillance for JD, which has important implications in light of future plans for national control, and the committee’s findings and recommendations. At the time of abstract submission, the committee’s report had not been released, but will be available by late summer.