Environmental distribution of M' paratuberculosis on cowcalf farms with clinical Johnes disease in W

1
Environmental distribution of M.
paratuberculosis on cow-calf farms with clinical
Johnes disease in Western Canada

• Dale Douma DVM
• Western College of Veterinary Medicine

2
Outline

• Introduction to the Johnes Disease
• Research
• Prevalence Study
• Wildlife Study
• Environment Study
• Conclusions

3
What is Johnes disease?

• Chronic granulomatous enteritis of ruminants
• Signs include
• Profuse diarrhea
• Severe weight loss
• Altered lining of the intestine
• Thickened and corrugated mucosa
• Caused by Mycobacterium paratuberculosis

http//www.johnes.org
4
History of Johnes

• Bacterial cause discovered by Dr. H. Johne and
  Dr. L. Frothingham in 1895 in Germany
• Acid fast bacteria similar to M. avium and
  pathology similar to intestinal tuberculosis in
  cattle
• First found in North America in 1908

http//www.johnes.org/history/index.html
5
M. paratuberculosis

• aka M. avium paratuberculosis Map
• Virtually identical to M. avium genetically
  (gt99)
• Behaves differently
• Mycobactin dependant for iron transport
• Slower growing
• Primarily infects ruminants but not exclusively

6
M. paratuberculosis

• Small Gram-positive rod-shaped bacterium
• Acid Fast positive
• Tendency to clump together
• Waxy rough cell wall
• Can survive outside of host
• Replicates inside of macrophages

7
Johnes Disease Transmission Cycle
Pictures from http//www.johnes.org
8
Why present at ADED?

• Cattle prevalence increasing
• Host range expanding?
• Other ruminants
• Non-ruminants
• Primates
• Zoonotic concern
• Crohns disease
• Positive association evident

http//www.johnes.org/zoonotic/index.html
9
Research Objectives

• Determine the seroprevalence of Map in Canadian
  beef cow-calf herds
• Survey wildlife present on cow-calf farms that
  may be infected with Map
• Characterize the distribution of Map within the
  environment of these cow-calf herds
• Evaluate the potential of using environmental
  sampling as a economical herd test

10
Seroprevalence Study

• Production Limiting Disease Committee research
  project
• Collected 4778 serum samples from 179 cow-calf
  herds across Canada in 2003
• excluding Manitoba and Quebec

11
(No Transcript)
12
Wildlife Survey

• Trapped wild rodents and birds on 6 cow-calf
  herds with clinical Johnes disease
• 4 rounds of trapping
• One round every 3 months for one year

13
Wildlife Survey

• Results all 4 rounds
• 202 Birds (sparrows, junco, swallows, etc)
• 236 Rodents (house mice, deer mice, RGS, etc)
• No positive samples
• Birds and rodents appear to be non susceptible or
  unaffected by Map due to low exposure on cow-calf
  farms

14
Coyote Survey

• Part of tuberculosis study by Dr. Gary Wobeser
  and Dr. Cheryl Sangster
• Lymph nodes collected from 82 trapped coyotes
  around Riding Mountain National Park and
  submitted for culture to the CFIA
• 0 positive for tuberculosis
• 3 positive for Map (3.7 95 CI 0-7.7)
• Significance
• First report of Map cultured from multiple
  coyotes at one location
• Further research required

15
Map of trapped coyote locations
RMNP
Blue Map Negative Red Map Positive
16
Environmental Study

• Method
• Enrolled 27 herds with a history of clinical
  Johnes disease
• Collected approx. 15 environmental samples per
  herd during the calving season
• Collected manure from up to 150 cattle per herd
  to estimate prevalence
• Cultured in pools of 5
• Compared results of test methods

17
Environmental Study

• Results
• Water Samples
• 26 biofilm samples, 54 samples from waterers, 21
  dugout samples, and 13 farm drainage samples
  including creeks and rivers
• 0 culture positive for Map

18
Environmental Study

• 243 non-water environmental samples were
  collected
• 15 (6.2) were positive for Map
• chute systems 4/26 (15.6)
• outside cattle feeders 3/21 (14.3)
• inside cattle feeders 2/21 (9.5)
• mothering-up pens 2/13 (15.4)
• bullpens 1/7 (14.3)
• turnout pens 1/10 (10.0)
• calf shelters 1/18 (5.6)
• calving pens 1/26 (3.8)
• No Map was detected in 101 samples from pastures
  (24), hospital pens (19), manure storage areas
  (17), young stock pens (10), creep feeders (7),
  mineral supplements (4), calf pens (2), and other
  areas of owner concern (18).

19
Environmental Study

• Results for Environmental Testing as a Herd Test
• 8 of 27 (29.6) herds had at least one positive
  environmental sample
• 17 of 27 (63.0) herds had at least one positive
  fecal pool
• 2 of 27 (7.4) herds were positive only on
  environmental sampling
• 9 of 27 (33.3) herds were positive only with
  fecal pool cultures

20
In Conclusion

• At this time
• Johnes prevalence in cow-calf herds in Canada is
  relatively low
• Environmental contamination of Map on cow-calf
  farms is low
• The time to act is now
• Environmental sampling as done in this research
  study is not sensitive enough at this time to
  replace animal sampling

21
Thank you!

• Funding Agencies
• Agriculture Development Fund of Saskatchewan
• Beef Cattle Research Council
• Beef Development Fund of Saskatchewan
• Wildlife Health Fund
• Interprovincial Graduate Student Fellowship