Ovine Johne's Disease (OJD) is the description given to sheep suffering from a mycobacterium paratuberculosis (prognosis negative) infection.   The symptoms are a general "wasting" of infected animals over a period of years. OJD is often mistaken for a range of other problems (abscess, worms, fluke, and dietary deficiency).  OJD is known to be spread by ingestion of pasture contaminated with infected fecal matter, and is known to be spread by the transport of infected fecal matter in waterways. Young animals are more susceptible, and it appears that they can be infected by mother's milk. The bacterium has been reported to persist for longer than one year on the pasture. The question as to whether wildlife can carry OJD remains unanswered, but it is known that Bovine Johne's Disease, although a strain distinct from OJD, can be carried by sheep.  With present technology it is not possible to reliably diagnose OJD in individual live sheep.  Recent advances have reduced the unit cost and accuracy of testing with a "pooled fecal culture" (PFC) test.  If OJD is present the entire flock is assumed to be infected.

OJD in NSW AUSTRALIA   Losses up to 6% have been reported in Australia.  In NZ and other countries where the disease is endemic anecdotal evidence is that losses stabilize in the range 1% to 3% p/a.  OJD was first detected in Australia circa 1980 in the central tablelands of NSW, and as of 1 August 1999, 49% of the 422 flocks confirmed as infected in NSW are in the central tablelands.   A further 930 flocks are classified as "suspect". (LAND; page 9, 16 September 1999).

Wool farmers who volunteer to have their flocks tested by the AAHC continue to find themselves in a "lose-lose" situation.  It is financially preferable to shear an unknown status flock, accept any losses (where 1% to 5% loss p/a is normal) and hope (if OJD has infected the flock) that natural selection will produce a resistant sheep variety.

The alternative is to be tested & either be declared OJD free & still be at risk of infection from wildlife or other means, or be confirmed as having OJD.  If confirmed the options are do nothing & continue life as a pariah or become one of the 50 producers taking part in the latest variation to the government's "control & evaluation" program. (P. Austin, p 14 LAND; 24 June 1999).

The recent government initiative (July 1999) is to nominate districts based on the count of farms within a region estimated as having OJD.  Trade from "residual" districts is restricted.  This action has produced some public criticism (mostly from producers in residual districts), and some support (mostly from producers in "control" districts.)    Those who are critical suggest that since effective eradication would cost around $150 - $200 million, perhaps research is required to establish an effective cure.

Supporters of the initiative doubt the accuracy of that cost without offering an alternative, defend the initiative as at least likely to slow the spread, and quote the possibility of the Crohns-Johnes link as sufficient reason to be Johnes free.  The Crohns-Johnes link is a tenuous argument for eradicating Johnes from sheep.  From my reading, the chief concerns of organizations such as Para are that the spread of Crohn's into the population is via pasteurized milk, with meat being a lesser concern.

Barvennon recently received a shonky form letter stamped with crests "NSW Farmers" and "NSW Agriculture" and another crest with the letter "R".  The letter stated that "NOJDP wants to raise $3 million" and demanded "all producers with carrying capacity greater than 50 DSE make a 'voluntary' contribution of at least $100" otherwise threatening that I "might" have to pay a compulsory levy of "more than $120."  The only identification was a PO box in Wagga Wagga, and a stamped signature alleged  to be that of someone called "K.P.Sheridan" above the words "director general".  Director general of what?  Do they think Australian farmers were born yesterday?  Then again, they might have found a few Pitt Street farmers whose "voluntary" contribution would have paid for the postage.

Local farmers have privately expressed the opinion that the Federal government ought to accept the blame for not taking care to exclude this disease from Australia by proper quarantine procedures.  Consensus is that the entire cost of eradication should be borne by the Federal government.

There is growing cynicism among sheep farmers about the procedure of government planning.  Farmers notice that government takes it's advice from public servants who are employed to control animal health.  For some decades these public officials managed the successful control program for footrot.  Perhaps too successful?  By the mid '90s many of these officials were facing retrenchment.  Other civil liberties being eroded or poached by special interest minorities are the right to own a gun or the right to choose whether to wear a seat belt.

HEALTH ASPECTS.  Research has uncovered persuasive evidence that suggests that Johne's disease (JD) of ruminants and Crohn's disease (CD) in humans is caused by the same organism.   Evidence suggests that mycobacterium paratuberculosis is present in our food and possibly in our water supplies.  The Veterinary Science faculty at the University of Wisconsin USA has published a page on the Zoonotic Potential of Johne's disease titled Association of M.paratuberculosis and Crohn's disease.

In Ireland Alan Kennedy has uncovered and detailed research which would tend to make any normal hypochondriac like myself think seriously about giving up pasteurized milk products for life.  His summary is particularly succinct.

Karen Meyer in the USA has collected and published very persuasive evidence on her site "crohns.org".  The Animal Health Councils continue to refuse to act because, they state:

"there is no evidence of a causative relationship".

        - Karen Meyer, speaking of the connection between Johne's disease & Crohn's disease.
 

In NSW Australia the Dairy Farmer's Association has volunteered to contribute at double the rate of beef producers to a levy designed to apply regional "control" to BJD.(LAND; 29 July p 9).  This is a welcome response, and shows a responsible approach by producers to this community health threat.

Associate Professor Warwick Selby of the RPAH Medical Centre in Sydney has begun a phase III clinical trial of anti paratuberculosis antibiotic therapy for Crohn's disease.  This trial follows "promising" results from Phase II trials.

The Center for Disease Control in Atlanta is unarguably the most important medical center for the study and control of human diseases in the world.  During a meeting with members of Para, officials from the CDC made the following statement about Crohns:

CDC is taking this matter very seriously.  CDC is now making moves that are supportive of the need to identify risk factors for human infection

SUMMARY