Trypanosomiasis is caused by the protozoan parasite Trypanosoma evansi. Clinical signs include fever, anemia, wasting, and skin lesions. T. evansi is transmitted between hosts by tabanid flies and infects the blood and body fluids. Affected animals show enlarged lymph nodes, emaciation, and weakness. At necropsy, there is anemia, organ enlargement, and tissue depletion. Diagnosis involves identifying the parasite in blood smears or tissues. Treatment uses drugs like quinapyramine, but control focuses on limiting vector transmission and detecting infected animals.

1. Faculty of Veterinary Science
Infectious Diseases II
(ProtozoalDiseases)
TRPANOSOMIOSIS
18th,May ,2016
SHAFI’I. A. M. SHEIKH

2. TRYPANOSOMIOSIS
Synonyms ; surra, triversa, nagana
Its infectious disease characterized by high rise
of temperature, anemia, wasting and
cutaneous eruptions. Trypanosomes are
flagellated protozoan parasites that live in the
blood and body fluids of their hosts

4. Etiology
The disease is caused by protozoan parasite
trypanosoma evansi, T.evansi is long slender
organism having free flagellum. The organism
are actively motile. They divide by binary
longitudinal fission. T.evansi can be grown in
novy macneal niccolle medium (NMN) and in
developing chick embryo

5. Epidemiology
the disease is widely distributed in tropical
and sub-tropical countries. Prevalent in middle
east, far east central and south America and
Africa. The trypanosomes are insect-born
disease of cattle, buffalo, goat, sheep, pig,
horses, donkey, camel and dog.

6. T.vivax is present in central and south America.
In India it was 1streported by evansi in 1918 in
camels. Whereas T.congolence and T.vivax are
responsible for severe disease in cattle , sheep
and goats. T.brucei usually causes a sub-
clinical infection but a severe disease in pigs.
T. simiae causes a very acute and highly fatal
disease in pigs.

7. Morbidity rate in cattle and pigs is 70%. The
disease is transmitted mechanically through
the bites of flies, tabanus, haemotopota,
lyperosia and stomoxys sp. 30 species of
tabanus are able to transmit T.evansi. it
transmit trypanosome through its saliva when
feeds on new host. Carrier animals remain as
potential source of disease transmission. It is
an important disease in camel and horses.

8. Pathogenesis
T.evansi multiply in blood circulation and
produce parasitimia. Metacylic trypanosomes
are infected in to the host by the fly during
feeding. They multiply at the sub-cutaneous
site, provoking a local pronounced in a fully
susceptible host and may be slight or absent
with some strains or species of trypanosomes.

9. In some hosts metacylic parasites change to
trypomastigate form and enter the blood stream
directly or through the lymphatics. T.vivax usually
multiply in blood and is eventually dispersed
throughout the cardio-vascular system, whereas
T.congolence tends to be aggregated in small
blood vessels and capillaries of the heart, brain
and skeletal muscle from where a small
proportion of parasites enter the blood
circulation. On other hand emaciation T.brucei
and rarely T.vivax multiply in the intestinal tissues
and serous fluids of body cavities.

10. Clinical finding
The cattle and buffalo usually carry sub-
clinical infection but overt disease may occur
due to stress, intercurrent infection, starvation
and debility. Transient rise in body
temperature. Enlargement of superficial
lymph glands, emaciation, progressive
weakness and anemia are the common clinical
finding. In horses and donkeys fever,
emaciation and edema are more common.

11. In camel intermittent fever progressive anemia,
emaciation and edema of dependent parts are
seen. Dog may suffer from acute form of
trypanosomiasis.

13. Necropsy finding
The carcass is marked by anemia, emaciation,
anasarca and enlargement of liver, spleen and
lymph nodes. Both fat stores are depleted
around the heart. There may be corneal
opacity and testicular degeneration.

14. Diagnosis
The diagnosis is based on the history and
symptoms. Demonstration of parasites in
blood films is confirmatory. Movements of the
parasite under hanging drop method can be
also seen. Biological test such as mice
inoculation test can be performed in doubtful
cases. Serum protein level and beta and
gamma globulin level have been found to
increase in affected animals.

15. There will also be low blood glucose level.
Beside mercuric chloride test, stibamidine test
and several serological test like, complement
fixation test, passive haemoagglutination test ,
indirect fluorescent antibody test and enzyme
liked immune-sorbent assay (ELISA) may be
performed.

18. Treatment
Drug used against T.evansi are Quinapyramin
sulphate that may be given as curative in camel,
buffalo, pig @ 4mg/kg body weight and
Quinapyramin prosalt is also used in cattle and
horses as curative as well as prophylactic @ 3.5
mg/kg body weight. Diminazine aceturuate
(Berenil) is also useful in cattle, buffalo, pig and
dog @ 8-10 mg/body weight. Some other
medicine have also been tired with good results.
Supportive therapy and 5% dextrose should also
be given.

19. As for all trypanosome diseases, drug
resistance due to misuse and especially by
using too small doses or diluting the drug with
water or some other liquid is an increasing
problem.

21. Control
Detection of infected animals should be done
promptly and isolation of the positive animals
should be done from rest of the herd.
Treatment of the animals should be
performed as early as possible. Vector should
be controlled as far as practicable.
Quinapyramin can be used as prophylaxis

22. Conclusion
This disease is an infectious disease and it is
characterized by high rise of temperature,
anemia, and wasting and cutaneous
eruptions. The species of trypanosomes the
infect livestock generally not transmissible to
humans with the possible exception of
T.brucei. they can be treated but prevention is
quite difficult.