The current status of JD research has been reviewed at national and international meetings and strategies to control the spread of Map have been presented. As part of these endeavors, in July 2000 the U.S. Department of Agriculture requested that the Board on Agriculture and Natural Resources of the National Academies convene a committee on the diagnosis and control of JD. Specifically, the committee was instructed to conduct a thorough review, evaluation, and compilation of all scientific research related to JD in domesticated and wild ruminants. The committee’s task was to: (1) review and synthesize current information regarding diagnostic techniques, mode of transmission, clinical expression, global prevalence, and potential animal and human health implications associated with JD in domesticated and wild ruminants; (2) evaluate current programs for controlling and preventing JD in ruminants; (3) provide policy recommendations for identification, monitoring, and management strategies applicable to U.S. livestock herds; (4) conduct an objective, critical assessment and summary of the state of knowledge regarding the relationship of JD in ruminants and Crohn’s disease in humans; and (5) provide recommendations on future research priorities and potential mechanisms to facilitate prevention and control of the disease.
Much of the emphasis in this report is on knowledge and control of JD in dairy cattle. This emphasis is difficult to avoid, because most of the published research, diagnostic test development, epidemiology, and control efforts have focused on dairy cattle. This could be the result of the higher prevalence of JD in dairy cattle, the potentially greater economic consequences of JD for the dairy industry, or the fact that some dairy management practices facilitate the introduction and spread of the agent within a herd. This report mirrors the bias toward dairy cattle, but the committee strove to address significant gaps in knowledge, research needs, and control measures for other species of domesticated livestock and wildlife. The committee anticipates that progress with other species will accelerate as JD control in dairy cattle advances.
In addition to discussions and recommendations on specific topics, the committee presents a broad outline of the steps that should be taken to control the disease, reduce the spread of Map, and minimize effects of the disease in animals. The committee also makes recommendations on research that should be undertaken to enhance control programs, to develop improved diagnostic tests and an efficacious vaccine, and to clarify the role of Map in the pathogenesis of Crohn’s disease.