Crohn’s disease in humans, combined with concern that Map is becoming widespread in the environment and the food chain, could transform JD into a serious public health problem.

Several approaches have been taken to begin addressing growing concern over JD. The National Johne’s Disease Working Group (NJWG) of the United States Animal Health Association has implemented an educational program to increase awareness among livestock producers, developed a voluntary herd status program to encourage producers to rear JD-free herds, and has developed minimum standards for state JD control programs. All of these efforts are yielding positive results, but the lack of a nationally coordinated control effort has limited progress and the sense of urgency continues to grow.


Participants at national and international meetings have reviewed the status of JD research and developed strategies to control the spread of Map. In July 2000, the U.S. Department of Agriculture (USDA) 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.

The committee reviewed the literature on diagnosis, modes of transmission, clinical expression, global prevalence, and potential animal and human health implications of JD with the following goals in mind:

  • Determine whether JD presents a problem sufficient to warrant control efforts.

  • Objectively review the data that provide the basis for control plans.

  • Identify significant gaps in knowledge that affect diagnosis and control.

  • Differentiate well-established facts from dogma or prevailing opinion.

  • Determine whether available diagnostic tests are adequate for control programs.

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