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February 19 1999


PARA represents the interests of Crohn's patients at the 6th International Colloquium on Paratuberculosis

Experts from around the world gather to discuss Paratuberculosis, Johne's Disease and Crohn's Disease

The International Association for ParatuberculosisExternal link indicator, an association of 200 scientists, veterinarians, doctors and others from 24 countries, held its 6th International Colloquium on Paratuberculosis in Melbourne, Australia. The Colloquium drew a large contingent from all over the world, including for the first time a presence from medical doctors concerned with the relationship between Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn's disease. The program was very detailed, covering four intensive days of lectures and meetings. To see the timetable of lectures and text of abstracts and posters presented at the meeting, please visit the Colloquium WebsiteExternal link indicator. Areas of interest to those with Crohn's disease and their families are discussed below.

Gastroenterology presence

For the first time at an IAP meeting, the gastroenterology community was represented. Among attendees concerned with human health and Crohn's disease were

  • Professor John Hermon-Taylor, a surgeon, clinician, and researcher from St. Georges Hospital Medical School in London, England, who has pioneered anti-paratuberculosis treatment for Crohn's disease, and whose research team has made fundamental advances in the understanding of this complex organism. Several current and former members of the St. Georges research team also attended the meeting, including Dr. Tim Bull, Dr. Nazira Sumar, Dr. Tim Doran and Dr. Mark Tizard. Drs. Doran and Tizard are now involved in animal paratuberculosis research in Australia.

  • Dr. William Chamberlin, a gastroenterologist from El Paso, TX, who has been treating Crohn's disease with anti-mycobacterial drugs for over five years.

  • Dr. Ira Shafran, a gastroenterologist from Orlando, FL, who is conducting research into the isolation of Mycobacterium avium subspecies paratuberculosis from Crohn's disease tissue, into the immune responses of Crohn's disease patients to Mycobacterium avium subspecies paratuberculosis and who is also treating some patients with anti-mycobacterial drugs.

  • Sharyn Leis RN, representing Dr. Tom Borody, a gastroenterologist from Sydney, Australia, whose pioneering work on antibiotic treatment for Helicobacter pylori infection led to eventual acceptance that a majority of duodenal and gastric ulcers are caused by H. pylori infection, in the face of strong resistance from the wider gastroenterology community.

  • Alan Kennedy, representing the Paratuberculosis Awareness and Research Association, a non-profit organization of Crohn's disease patients and their families whose stated goals are to raise awareness of the connection between Mycobacterium avium subspecies paratuberculosis and Crohn's disease, and who are lobbying for Crohn's disease research funds to be allocated towards Mycobacterium avium subspecies paratuberculosis.

It is certain that the presence from medical doctors had a strong effect on previously skeptical perceptions of the possible connection between Crohn's disease and Mycobacterium avium subspecies paratuberculosis, particularly on representatives of the Dairy and Beef industries.

Food Safety and Environmental Distribution

The survival of Mycobacterium avium subspecies paratuberculosis through milk pasteurization is still the subject of heated debate, with food industry representatives attempting to undermine many aspects of the research conducted by researchers from Queen's University, Belfast. Dr. I. GrantExternal link indicator, the lead researcher at Queen's University, informed the meeting that a definitive statement on the viability of the organisms found and the techniques used will be made in a future press release from the U.K. Ministry of Agriculture, Fisheries and FoodExternal link indicator (MAFF).

Reports of investigations of paratuberculosis in milk from Belgium and the Netherlands were presented. Both were unable to arrive at conclusions, due to the extreme difficulty in determining the viability of such a slow growing organism as Mycobacterium avium subspecies paratuberculosis against the microbiologically rich background contained in pasteurized milk.

No reports were presented on the survivability of Mycobacterium avium subspecies paratuberculosis in retail beef products, or the effect of cooking temperatures on the survivability of Mycobacterium avium subspecies paratuberculosis in beef, since no such research has been conducted.

No reports were presented on the presence of Mycobacterium avium subspecies paratuberculosis in water supplies, since no such research has been conducted.


There was much research presented in the area of Genetics and Molecular Biology. Among the more important points were

  • New Sequence Discovered. The team from St. Georges Hospital Medical School, who discovered the IS900 sequence (the only genetic sequence known to be unique to MAP), presented data about a new insertion sequence they have discovered. They have named the new sequence GS and think that it may also be unique to MAP. The sequence has a high "GC" (Guanine and Cytosine) content, and bears a close resemblance to sequences found in many bacteria which are pathogenic for humans. Moreover, when these sequences are removed from pathogenic bacteria, the latter lose their pathogenicity. The St. Georges researchers believe that the GS element may be a promising target for vaccine research, and hope to investigate this avenue further, although lack of research funding is hampering their efforts.

  • Genetic Susceptibility. New research from the Netherlands provides an indication that a subset of cattle have a genetic predisposition to developing disease when infected with Mycobacterium avium subspecies paratuberculosis, potentially meaning that only cattle that are genetically susceptible will develop clinical Johne's Disease. Although the nature of this genetic susceptibility is currently unknown, this finding has obvious implications for research into paratuberculosis in other species, including humans.

  • Sequencing the genome. It became clear at the meeting that progress in the development of effective diagnostics, treatments and vaccines will move rapidly forward if the genome of Mycobacterium avium subspecies paratuberculosis is sequenced. The estimated cost of this work is approx US$2 million. When it is considered that annual losses, on a global basis and in all species, resulting from Johne's disease is over US$5 billion, and that current medical expenditure for Crohn's disease, on a global basis, is over US$10 billion, the case for sequencing the genome is compelling, to say the least.

  • Inter-species transmission. The "accepted wisdom" in the farming community is that strains of paratuberculosis which cause disease in sheep do not cause disease in cattle, and vice-versa. However, recent data from the Netherlands and Iceland demonstrate that this is clearly not the case:- sheep strains can cross the species barrier to cause disease in cattle and cattle strains can cross the species barrier to cause disease in sheep.

  • Adaptive radiation. The prevalence of Mycobacterium avium subspecies paratuberculosis is being so greatly accelerated by current farming practices that Johne's Disease is being discovered in an ever increasing number of species and animal herds. Reports of emerging Johne's Disease problems reported at the meeting included American Bison herds, New Zealand red deer, South African sheep, and four species of primates.

Epidemiology and Eradication/Control Programs.

Points to note about the epidemiology of paratuberculosis include

  • Netherlands. The Netherlands is the only country in the world to have instigated a compulsory eradication program for Johne's Disease. The stated reasons for the Dutch program are
    1. To minimize the risk of human exposure to paratuberculosis.

    2. To minimize economic losses from Johne's Disease.

    Most interestingly, the Netherlands experience has shown that Johne's Disease eradication programs are economically viable, i.e. the high cost of an eradication program is recouped by the prevention of the enormous losses caused by Johne's Disease.

  • Live vaccine banned in Netherlands. It is important to note that, because of the risk that Mycobacterium avium subspecies paratuberculosis causes disease in humans, the use of live paratuberculosis vaccines is banned in the Netherlands. Only the use of killed vaccines is permitted.

  • Australia. The Australian State of Victoria has instigated an eradication program for Ovine Johne's Disease (OJD). The Victorian sheep industry has recognized that Johne's Disease is an industry problem, and that industry should pay to deal with the problem. The cost of the program will be met by a stamp duty on sales of sheep. This tax on the movement of animals should also have the effect of restricting the spread of disease.

  • Crisis point. The Bovine Johne's Disease (BJD) problem is so severe, anecdotal reports are appearing that up to 100% of cattle herds in some areas of the U.S.A. and Europe are infected with BJD.

  • The Iceberg Effect. This meeting brought the first public discussion and acceptance of the "Iceberg Effect", i.e. when only 1 or 2 individuals animals in a herd test positive for Johne's Disease, up to one third of the animals in the herd may already be infected and be destined to develop disease in the future.

For further information contact

ContactKaren Meyer
Executive Director, Paratuberculosis Awareness and Research Association, Inc.

Paratuberculosis Awareness and Research Association, Inc.

is a non-profit organization of Crohn's disease patients, their families and friends who are dedicated to the following goals:
  1. To raise awareness of the zoonotic (disease-causing) potential of the bacterium, MAP, in the national community of sufferers of Crohn's disease, in medical, veterinary and food science research communities, in governmental agencies and in the public in general
  2. To urge governmental agencies to directly address control and eventual eradication of MAP from the human environment, particularly from foods of animal origin
  3. To urge governmental and medical research agencies to make funding available for research which will determine the role played by MAP in causing Crohn's disease

Paratuberculosis Awareness and Research Association, Inc.
Box 16219
Temple Terrace, FL 33687-6219

Source:   Contact PARA:
Paratuberculosis Awareness & Research Association