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Identifying Pre-Clinical MAP Infected Cattle


Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne’s disease, a chronic infectious disease of ruminants. Infection normally occurs in the neonatal period when calves ingest an infectious dose of MAP. The clinical, irreversible and ultimately fatal disease does not occur until years later. In the meantime, animals with preclinical Johne’s disease may look healthy while still shedding MAP in their feces, transmitting the disease to new animals.

There are no effective vaccines or treatments, and diagnostic tests fail to identify many infected animals in the pre-clinical state. Research currently underway and funded by the National Check-off and Canada’s Beef Science Cluster is working to identify proteins secreted by MAP that can elicit a MAP-specific cell mediated immune response. A reliable, sensitive, specific diagnostic test that accurately identifies MAP carriers in the early stages of infection would greatly help efforts to control the disease in beef herds.

To learn more about this research, see the BCRC fact sheet
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Grant LastiwkaOctober 14, 2015

I am very interested in the MAP study. I run a small cattle herd and did buy an infected animal about 15 years ago. One and a half years later she showed the signs and our veterinarian diagnosed it we culled her and her offspring. Thirteen years later we had another case and tested several bloodlines in herd. A few of the 13 and 14 year old cows showed that they were carriers as well as a few younger. They showed no signs, no dirty tails whatsoever. We culled them but did keep some of their offspring. So we are keeping the problem I am sure but it does not manifest itself as often as I thought it would. No one in the beef industry seems to admit it is in their herds. This cannot be accurate with cow trading the way it is. More work needs done as this is a disease too close to human colitis if I am not mistaken.


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