Changes

Also known as: '''''Paratuberculosis

Also known as: '''''Paratuberculosis

Caused by '''''''M avium'' subsp. ''paratuberculosis''

Caused by '''''M avium'' subsp. ''paratuberculosis''

==Description==

==Introduction==

Johne's Disease is a contagious and chronic disease of ruminants caused by the bacterium ''Mycobacterium avium subsp. paratuberculosis''. Affected species include cattle, sheep, goats and camelids. The disease is present worldwide with the highest prevalence occurring in dairy cattle. In these animals the disease is responsible for severe economic losses due to reduced reproductive performance, increased susceptibility to disease, reduced milk production and culling losses. Subclinical carriers can occur, shedding organisms in their faeces.

Johne's Disease is a contagious and chronic disease of ruminants caused by the bacterium ''Mycobacterium avium subsp. paratuberculosis''. Affected species include cattle, sheep, goats and camelids. The disease is present worldwide with the highest prevalence occurring in dairy cattle. In these animals the disease is responsible for severe economic losses due to reduced reproductive performance, increased susceptibility to disease, reduced milk production and culling losses. Subclinical carriers can occur, shedding organisms in their faeces.

==Diagnosis==  

==Diagnosis==  

Diagnosis is difficult, particularly in the case of subclinical disease as there is no single test that will detect all stages of the disease. '''Bacterial culture''' is the most definitive test but is time-consuming, requiring up to twelve weeks for incubation.  

Diagnosis is difficult, particularly in the case of subclinical disease as there is no single test that will detect all stages of the disease. '''Bacterial culture''' is the most definitive test but is time-consuming, requiring up to sixteen weeks for incubation.  

The most commonly used diagnostic test is the [[ELISA testing|'''ELISA''']] which detects antibodies to ''M. paratuberculosis'' in clinically affected animals. This is typically used in combination with post mortem and identification of the classic pathological lesions of the disease. Other commercially available tests include bacterial culture, '''PCR''' and '''agar gel immunodiffusion'''. Test sensitivity may be increased by using different tests in combination.

The most commonly used diagnostic test is the [[ELISA testing|'''ELISA''']] which detects antibodies to ''M. paratuberculosis'' in clinically affected animals. This is typically used in combination with post mortem and identification of the classic pathological lesions of the disease. Other commercially available tests include bacterial culture, '''PCR''' and '''agar gel immunodiffusion'''. Test sensitivity may be increased by using different tests in combination.

Inactivated adjuvanted vaccines are available and reduce shedding of mycobacteria but do not eliminate infection.

Inactivated adjuvanted vaccines are available and reduce shedding of mycobacteria but do not eliminate infection.

[[File:CABI logo.jpg|left|90px]]

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[http://www.cabdirect.org/search.html?it=any&q1=%28title%3A%28%22Johne%27s+disease%22%29+OR+title%3A%28%22Johnes+disease%22%29+OR+title%3A%28Paratuberculosis%29%29+AND+od%3A%28cattle%29&calendarInput=yyyy-mm-dd&occuring1=freetext&show=all&rowId=1&rowId=2&rowId=3&options1=AND&options2=AND&options3=AND&occuring3=freetext&occuring2=freetext&publishedend=yyyy&la=any&publishedstart=2000&fq=sc%3A%22ve%22&y=5&x=67 Johne’s disease in cattle publications since 2000]

[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%28%28title%3A%28%22Johne%27s+disease%22%29+OR+title%3A%28%22Johnes+disease%22%29+OR+title%3A%28Paratuberculosis%29%29+AND+%28od%3A%28sheep%29+OR+od%3A%28goats%29%29%29+&occuring1=freetext&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=40&y=10 Johne’s disease in sheep and goats publications since 2000]

[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%28%28title%3A%28%22Johne%27s+disease%22%29+OR+title%3A%28%22Johnes+disease%22%29+OR+title%3A%28Paratuberculosis%29%29+AND+%28od%3A%28sheep%29+OR+od%3A%28goats%29%29%29+&occuring1=freetext&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=40&y=10 Johne’s disease in sheep and goats publications since 2000]

==References==

==References==

* Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''' ''Merial''

* Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''' ''Merial''

[[Category:Enteritis,_Bacterial]][[Category:Enteritis, Proliferative]][[Category:Cattle]][[Category:Sheep]][[Category:Goat]]

 

[[Category:Enteritis,_Bacterial]][[Category:Enteritis, Proliferative]][[Category:Intestinal Diseases - Cattle]][[Category:Alimentary Diseases - Sheep]][[Category:Alimentary Diseases - Goat]]

[[Category:Enteritis,_Granulomatous]][[Category:Deer]]

[[Category:Enteritis,_Granulomatous]][[Category:Deer]]

[[Category:Expert Review]]

[[Category:Brian Aldridge reviewing]]

[[Category:Mycobacterium_species]]

[[Category:Mycobacterium_species]]