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Also Known As — '''''Nagana'''''—'''''Typanosomiasis'''''—'''''Chagas' Disease'''''—'''''Sleeping sickness'''''—'''''Parrot Sickness
Also Known As: '''''Nagana — Trypanosomiasis — Chagas' Disease — Sleeping Sickness — Parrot Sickness'''''
==Introduction==
==Introduction==
[[File:Trypanosoma.jpg|thumb|200px|right|''T.cruzi''. Wikimedia Commons]]
Trypanosomosis is a disease caused by '''[[Protozoa | protozoan]]''' pathogens of the genus [[Trypanosoma]]. They are '''obligate parasites''' and can infect mammals, birds, reptiles, amphibians and fish.
Trypanosomosis is a disease caused by '''[[Protozoa | protozoan]]''' pathogens of the genus [[Trypanosoma]]. They are '''obligate parasites''' and can infect mammals, birds, reptiles, amphibians and fish.
'''Stercorarian trypanosomes''' develop within an '''insect''' vector and are transmitted to mammals in the faeces of the vector.
'''Stercorarian trypanosomes''' develop within an '''insect''' vector and are transmitted to mammals in the faeces of the vector.
'''Salivarian''' trypanosomes develop within '''[[Glossinidae | tsetse flies]]''' and mammals are infected through their bites.
'''Salivarian''' trypanosomes develop within '''[[Glossinidae |tsetse flies]]''' and mammals are infected through their bites.
For more information about the various species see [[Trypanosoma]] page.
Trypanosomosis causes a '''wasting disease''' in cattle and '''sleeping sickness''' in humans.
Trypanosomosis causes a '''wasting disease''' in cattle and '''sleeping sickness''' in humans.
'''''T. cruzi''''' is the most important species in veterinary medicine.
'''''T. cruzi''''' is the most important species in veterinary medicine.
Trypanosomosis is '''notifiable''' to the World Organisation for Animal Health [http://www.oie.int/ (OIE)]
Trypanosomosis is '''notifiable''' to the World Organisation for Animal Health [http://www.oie.int/ (OIE)].
==Signalment==
==Signalment==
'''Calves''' less than a year old are more resistant than adults, but lambs and kids appear more susceptible to ''T. congolense'' infections.
'''Calves''' less than a year old are more resistant than adults, but lambs and kids appear more susceptible to ''T. congolense'' infections.
Cattle 6-9yrs old appear most susceptible to trypanosomosis.
Cattle 6-9yrs old appear most susceptible to trypanosomosis.
==Transmission==
==Transmission==
Trypanosomosis is spread by '''[[Glossinidae|Tsetse flies]]''' and other insect vectors.
Trypanosomosis is spread by '''[[Glossinidae|Tsetse flies]]''' and other insect vectors.
[[File:Triatoma infestans.jpg|thumb|200px|right|Triatomid - "kissing bug". (WHO - Wikimedia Commons)]]
[[File:Triatoma infestans.jpg|thumb|200px|right|Triatomid - "kissing bug". (WHO - Wikimedia Commons)]]
[[Tabanidae | Horse flies]] and [[Stomoxys calcitrans | stable flies]] can also act as mechanical vectors for some [[Trypanosoma | ''trypanosoma'']] species, but the parasites can not undergo lifecycle development within these hosts.
[[Tabanidae | Horse flies]] and [[Stomoxys calcitrans |stable flies]] can also act as mechanical vectors for some [[Trypanosoma | ''trypanosoma'']] species, but the parasites cannot undergo lifecycle development within these hosts.
''T. vivax'' and ''T. evansi'' are reported to achieve Transplacental transmission. <ref>Ikede, B. O., Loso, G. J.(1972). '''Hereditary transmission of Trypanpsoma vivax'''. Brit Vet J, 128:i-ii</ref>
''T. vivax'' and ''T. evansi'' are reported to achieve transplacental transmission. <ref>Ikede, B. O., Loso, G. J.(1972). '''Hereditary transmission of Trypanosoma vivax'''. Brit Vet J, 128:i-ii</ref>
==Distribution==
==Distribution==
Significant losses may also be caused by increased susceptibility and prevalence of other concurrent diseases where trypanosomosis is present.
Significant losses may also be caused by increased susceptibility and prevalence of other concurrent diseases where trypanosomosis is present.
Multisystemic signs can be seen in any species so diagnosis from clinical examination is often impossible as no pathognomic signs are evident.
Multisystemic signs can be seen in any species so diagnosis from clinical examination is often impossible as no pathognomonic signs are evident.
===Ruminants===
===Ruminants===
Enlarged '''[[Lymph Nodes - Anatomy & Physiology|lymph nodes]]''' and '''[[Spleen - Anatomy & Physiology|spleen]]'''.
Enlarged '''[[Lymph Nodes - Anatomy & Physiology|lymph nodes]]''' and '''[[Spleen - Anatomy & Physiology|spleen]]''' are the most common sign. Later in the disease course the lymph nodes and spleen shrink due to '''lymphoid exhaustion'''.
'''Haemolytic anaemia''' is a cardinal feature. Chronic infection causes '''[[:Category:Heart Failure|heart failure]]''' and associated signs and death.
'''Haemolytic anaemia''' is a cardinal feature.
Chronic infection causes '''heart failure''' and associated signs and death.
Plasma cell hypertrophy and '''hypergammaglobulinaemia''' are evident on haematology and biochemistry.
Plasma cell hypertrophy and '''hypergammaglobulinaemia''' are evident on haematology and biochemistry.
Emaciation
Emaciation, '''abortion''', premature births and infertility are features, and '''orchitis''' in males reduces fertility.
'''Abortion''', premature births and infertility are features, and '''orchitis''' in males reduces fertility.
===Horses===
===Horses===
'''Oedema''' of the '''limbs''' and '''genitalia'''.
'''Oedema''' of the '''limbs''' and '''genitalia''' is very common.
'''Dourine''' – genital and abdominal '''oedema''', paraphimosis, '''urticarial plaques''' known as “silver dollar spots” and neurological signs. Disease is usually mild and recurrent but can be fatal.
'''Dourine''' – genital and abdominal '''oedema''', paraphimosis, '''urticarial plaques''' known as “silver dollar spots” and neurological signs may all be present. The disease is usually mild and recurrent but can be fatal.
===Donkeys===
===Donkeys===
[[Protozoal Skin Infections - Donkey|Skin infections]]
See [[Protozoal Skin Infections - Donkey|donkey skin infections]] page for details.
===Dogs and Cats===
===Dogs and Cats===
'''Pyrexia''', myocarditis, '''myositis''', corneal opacity and '''neurological signs'''.
'''Pyrexia''', myocarditis, '''myositis''', corneal opacity and '''neurological signs''' may all be present.
==Diagnosis==
==Diagnosis==
[[File:Trypanosomes blood.gif|thumb|200px|right|Trypanosomes in blood]]
[[File:Trypanosomes blood.gif|thumb|200px|right|Trypanosomes in blood]]
Microscopic identification on trypanosome parasites in the host blood on a '''smear''' with Giemsa staining.
Microscopic identification on trypanosome parasites in the host blood on a '''smear''' with Giemsa staining is commonly performed. Where low levels of parasitaemia are present, filtration or haemolysis of a whole blood sample may be required and motile trypanosomes may be demonstrable in a haematocrit tube at the '''plasma: buffy coat''' interface.
Where low levels of parasitaemia are present, filtration or haemolysis of a whole blood sample may be required and motile trypanosomes may be demonstrable in a haematocrit tube at the '''plasma: buffy coat''' interface.
On '''post-mortem''' examination, carcasses are often pale and oedematous due to anaemia and emaciation. Degenerative lesions can be found on the heart, liver, lymph nodes, testes, brain, conjunctiva, cornea, spleen, kidney and endocrine organs.
On '''post-mortem''' examination, carcasses are often pale and oedematous due to anaemia and emaciation. Degenerative lesions can be found on the heart, liver, lymph nodes, testes, brain, conjunctiva, cornea, spleen, kidney and endocrine organs.
Many other seroimmunological techniques are also available variably in laboratories.
Many other seroimmunological techniques are also available variably in laboratories.
==Treatment==
==Treatment==
A variety of drugs can be used to treat trypanosomosis including '''diminazene, homidium, isometadium, suramin''' and '''melarsomine'''.
A variety of drugs can be used to treat trypanosomosis including '''diminazene, homidium, isometadium, suramin''' and '''melarsomine'''.
'''Diminazene aceturate''' is most commonly used and is frequently '''curative'''. It however causes frequent local reactions in horses so should be given in multiple deep muscular sites and massaged well. The drug is also contraindicated in dogs and camels due to vascular damage. Diminazene also has a prophylactic effect for up to 3 months.
'''Diminazene aceturate''' is most commonly used and is frequently '''curative'''. It however causes frequent local reactions in horses so should be given in multiple deep muscular sites and massaged well. The drug is also ''contraindicated in dogs and camels'' due to vascular damage. Diminazene also has a prophylactic effect for up to 3 months.
==Control==
==Control==
'''Separation''' of livestock and wild animals is effective but difficult.
'''Separation''' of livestock and wild animals is effective but difficult.
Use of '''trypanotolerant''' livestock breeds is the only option is some areas where economic restraints prevent constant treatment and control.
Use of '''trypanotolerant''' livestock breeds is the only option is some areas where economic restraints prevent constant treatment and control.
'''[[Glossinidae | Tsetse fly]] control''' by sprays, traps, dips and release of sterile male flies is effective but expensive and time consuming.
'''[[Glossinidae |Tsetse fly]] control''' by sprays, traps, dips and release of sterile male flies is effective but expensive and time-consuming.
Prophylactic drug therapy is also effective but costly.
Prophylactic drug therapy is also effective but costly.
Merck Veterinary Manual, '''Tsetse-transmitted Trypanosomiasis''' accessed online 03/06/2011 @ http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/10413.htm
Merck Veterinary Manual, '''Tsetse-transmitted Trypanosomiasis''' accessed online 03/06/2011 @ http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/10413.htm
[[Category:[[Category:To Do - CABI review]]]]
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[[Category:Cardiovascular Diseases - Cattle]][[Category:Cardiovascular Diseases - Horse]][[Category:Lymphoreticular and Haematopoietic Diseases - Cattle]][[Category:Lymphoreticular and Haematopoietic Diseases - Horse]][[Category:Reproductive Diseases - Horse]][[Category:Reproductive Diseases - Cattle]]
[[Category:CABI Expert Review]]