Changes

Also Known As – '''''Pasture Fever''''' – '''''Tickborne Fever''''' – '''''Ruminant Anaplasmosis''''' – '''''TBF'''''

Also Known As: '''''Pasture Fever''''' — '''''Tickborne Fever''''' — '''''Ruminant Anaplasmosis''''' — '''''TBF'''''

 

Caused By – ''[[Anaplasma phagocytophilum]]'', previously known as ''Ehrlichia phagocytophila''

Caused By: ''[[Anaplasma phagocytophilum]]'', previously known as ''Ehrlichia phagocytophila''

 

==Introduction==

==Introduction==

[[File:Ixodes.jpg|thumb|200px|right|Ixodes tick. Wikimedia commons]]

[[File:Anaplasmosis.jpg|thumb|200px|right|''Rickettsia'' spp. inside tick haemolymph cells. Sourced from Wikimedia Commons]]

Tick Borne Fever is a '''[[Rickettsiales | rickettsial]]'' disease affecting the '''[[Leucocytes | white blood cells]]''' of sheep and cattle, causing '''anaemia''' and seasonal “pasture fever”.

[[File:Swollen tick-SteveFE.jpg|thumb|200px|right|''Ixodes'' tick. Sourced from Wikimedia commons]]

Tick Borne Fever is a '''[[Rickettsiales |rickettsial]]'' disease affecting the '''[[Leucocytes |white blood cells]]''' of sheep and cattle, causing '''anaemia''' and seasonal “pasture fever”.

Seasonal pasture fever occurs in cattle that are returned to tick infected pasture in the Spring.

Seasonal pasture fever occurs in cattle that are returned to tick infected pasture in the Spring.

Human granulocytic ehrlichiosis, the '''zoonotic''' form of TBF is a potentially '''fatal''' disease reported in the UK, Europe and USA.

Human granulocytic ehrlichiosis, the '''zoonotic''' form of TBF is a potentially '''fatal''' disease reported in the UK, Europe and USA.

==Signalment==

==Signalment==

TBF naturally affects primarily sheep and cattle, and less commonly, deer, horses and dogs.

TBF naturally affects primarily sheep and cattle, and less commonly, deer, horses and dogs.

==Distribution==

==Distribution==

TBF has worldwide distribution including the UK.

TBF has worldwide distribution including the UK. It is transmitted by '''[[Ixodes spp. |Ixodes]]''' ticks. Both adults and nymphs can transmit the disease. Transmission is '''[[Tick Disease Transmission |trans-stadial]].'''

==Clinical Signs==

==Clinical Signs==

TBF causes '''multisystemic''' disease, causing cardiovascular, gastrointestinal, respiratory, reproductive and neurological signs, and also lymphadenopathy and wasting disease.

TBF causes '''multisystemic''' disease, causing cardiovascular, gastrointestinal, respiratory, reproductive and neurological signs, and also lymphadenopathy and wasting disease.

'''Severe haematological changes''' including profound '''anaemia''' and '''leucopaenia''' cause significant clinical signs.

'''Severe haematological changes''' including profound [[:Category:Anaemia|'''anaemia''']] and '''leucopaenia''' cause significant clinical signs.

Initial lymphocytopaenia and '''prolonged neutropaenia''' are also features of TBF.

Initial [[lymphocytopaenia]] and '''prolonged [[neutropaenia]]''' are also features of TBF.

A profound '''eosinophilia''' will occur for 17-20 days post-infection. <ref>Miert, A. S. J. P. A. Mvan., Duin, C. T. Mvan., Schotman, A. J. H., Franssen, F. F.(1984). Clinical, haematological and blood biochemical changes in goats after experimental infection with tick-borne fever. Vet Parasitology, 16(3/4):225-233; 29 </ref>

A profound '''[[eosinophilia]]''' will occur for 17-20 days post-infection. <ref>Miert, A. S. J. P. A. Mvan., Duin, C. T. Mvan., Schotman, A. J. H., Franssen, F. F. (1984) '''Clinical, haematological and blood biochemical changes in goats after experimental infection with tick-borne fever. '''''Vet Parasitology, ''16(3/4):225-233; 29 </ref>

Low serum Alkaline Phosphatase (ALP) and decreased zinc, iron and albumin are also common biochemical findings, along with high urea, creatinine and bilirubin.

Low serum Alkaline Phosphatase (ALP) and decreased zinc, iron and albumin are also common biochemical findings, along with high [[urea]], creatinine and [[bilirubin]].

Recovered animals develop immunity but it is unknown how long this is effective for.

Recovered animals develop immunity but it is unknown how long this is effective for.

==Diagnosis==

==Diagnosis==

Haematological and Biochemical changes as listed above along with '''marked pyrexia''' are highly suggestive, especially if historical findings are conducive.  

Haematological and Biochemical changes as listed above along with '''marked pyrexia''' are highly suggestive, especially if historical findings are conducive.  

Demonstration of the '''organism''' in the '''[[Leucocytes | leucocytes]]''' in peripheral blood is confirmative.

Demonstration of the '''organism''' in the '''[[Leucocytes |leucocytes]]''' in peripheral blood is confirmative.

On '''post-mortem''' examination, the '''[[Spleen | spleen]]''' is enlarged and mild liver damage is common.  

On '''post-mortem''' examination, the '''[[Spleen - Anatomy & Physiology|spleen]]''' is enlarged and mild liver damage is common. Lesions within the [[Lungs - Anatomy & Physiology|'''lung''']] are present and contain mononuclear infiltrate on histopathology. Thickening, ulceration and haemorrhage of the gastrointestinal tract become worse distally.

Lesions within the '''lung''' are present and contain mononuclear infiltrate on histopathology.

Thickening, ulceration and haemorrhage of the gastrointestinal tract become worse distally.

The parasites may be visible within the neutrophils in sections of liver and lung.

The parasites may be visible within the neutrophils in sections of liver and lung.

Antibodies can be detected using '''Indirect Immunofluorescence''' (IFAT), '''Complement Fixation''' and Immunoelectrophoresis (CIEP).

Antibodies can be detected using [[FAT|'''Indirect Immunofluorescence''' (IFAT)]], '''[[Complement Fixation]]''' and Immunoelectrophoresis (CIEP).

 

==Treatment==

==Treatment==

''E. phagocytophila'' is susceptible to '''oxytetracycline, sulphamethazine, sulphadimidine, doxycycline''' and '''trimethoprim-sulphonamides'''.

''A. phagocytophilum'' is susceptible to '''oxytetracycline, sulphamethazine, sulphadimidine, doxycycline''' and '''trimethoprim-sulphonamides'''.

 

==Control==

==Control==

Control of the [[Ticks | tick]] vector is expensive but effective.  

[[Tick Control|Control of the tick vector ]]is expensive but effective.  

Use of [[Ectoparasiticides | ectoparasiticides]] and tick resistant breeds is also valuable.

Use of [[Ectoparasiticides |ectoparasiticides]] and tick resistant breeds is also valuable.

 

==Human Granulocytic Ehrlichiosis==

==Human Granulocytic Ehrlichiosis==

Causes fever, malaise, headaches, sweats, nausea, confusion, anorexia, vomiting, weakness, diarrhoea, pneumonia, vertigo, seizures, GI bleeding and a skin rash.<ref>Bakken, J. S., Krueth, J., Tilden, R. L., Dumler, J. S., Kristiansen, B. E.(1996). Serological evidence of human granulocytic ehrlichiosis in Norway. Eur J Clin Microbiol Inf Dis, 15(10):829-832; 12</ref>

Causes fever, malaise, headaches, sweats, nausea, confusion, anorexia, vomiting, weakness, diarrhoea, pneumonia, vertigo, seizures, GI bleeding and a skin rash.<ref>Bakken, J. S., Krueth, J., Tilden, R. L., Dumler, J. S., Kristiansen, B. E. (1996). '''Serological evidence of human granulocytic ehrlichiosis in Norway. '''''Eur J Clin Microbiol Inf Dis,'' 15(10):829-832; 12</ref>

 

{{Learning

{{Learning

|flashcards = [[Tick-Borne Fever Flashcards]]

|flashcards = [[Tick-Borne Fever Flashcards]]

}}

}}

==References==

==References==

 

 

 

 

[[Category:Rickettsiales]][[Category:Cattle Bacteria]][[Category:Sheep Bacteria]][[Category:Goat Bacteria]]

[[Category:Rickettsiales]][[Category:Cattle Bacteria]][[Category:Sheep Bacteria]][[Category:Goat Bacteria]]

[[Category:To Do - CABI review]]

[[Category:Zoonoses]]

[[Category:Cardiovascular Diseases - Cattle]][[Category:Respiratory Diseases - Cattle]][[Category:Alimentary Diseases - Cattle]][[Category:Reproductive Diseases - Cattle]][[Category:Neurological Diseases - Cattle]][[Category:Lymphoreticular and Haematopoietic Diseases - Cattle]]

[[Category:CABI Expert Review]]