Trypanosoma evansi 伊氏锥虫 CLASS 3 speaker:刘思玲 materials by吴云燕 张敏静 孙娜 ppt by刘务玲

Introduction Morphology Life cycle Epidemology Symptoms Lesions Diagnosis Control Reference

Introduction What is Trypanosomosis/surra disease? (伊氏锥虫病/苏拉病) A disease is caused by Trypanosoma evansi（伊氏锥虫） transmitted by blood-sucking insect(吸血昆虫)

Introduction Hosts: Site of infection: Distribution: cattle, goat , sheep, camel（骆驼），equines（马属动物），dog, deer, elephant, tiger, rabbit, guinea pig(豚鼠), rat, mice Site of infection: blood, lymph(淋巴液)，ncurolymph（脑脊液） distributed to tissues and organs through the blood Distribution: Trypanosomosis is more common in tropical(热带) and subtropical zone（亚热带）.

Morphology monomorphic in form（单行型锥虫） willow-like(柳叶状) The nucleolus(细胞核) is oval and lies in the center of parasite. An free flagellum(一根游离鞭毛) length：18~34μm width:1~2μm

Morphology

Life cycle blood-sucking insect as mechanical transmission vectors no cyclic development in vectors reproduction: longitudinal binary fission in blood, lymph and blood-forming organs .

Epidemiology Susceptible animals（易感动物）: (1)mostly domestic animals and wild animals ; (2)Trypanosoma evansi in different geographic area has different hosts.

Epidemiology Source of infection（传染来源）: （1）animals infected （2）animals with ever drug treatment failed to kill the pathogeny(病原)

4 Epidemiology Route of infection(感染途径)： Tabanus(虻属) ： the most important vectors vampire bat(吸血蝠) carnivore(肉食兽) :infected by food contained with Trypanosoma evansi. Incomplete disinfection surgical instruments(消毒不完全的手术器械), including injection equipment that used in infected animals can disseminate infection to the healthy ones.

Epidemiology Epidemiology season: related to the activity season of vector insects.

Symptoms The symptoms are different based on different animals. Equines（马属动物）have stronger susceptibility. Camels The disease is called camel flies epidemic disease or the green dry disease(骆驼伊氏锥虫病俗称，驼蝇疫，青干病) Cattles and buffloes The disease is a typical course of chronic infection(慢性感染). But in dogs and cats, The disease is an acute and deadly course.

Lesions Characteristic: subcutaneous dropsy(皮下水肿) sometimes hydrothorax and ascites(胸腔积液和腹水) Spleen(脾脏) and lymph node（淋巴结） become enlarged. ecchymosis(出血斑) in gastric mucosal of ruminated animals(反刍动物)

Diagnosis Collection of samples: Examination (1)blood from infected domestic animal (2)skin exudation (3)lymph node Examination (1)Giemsa(吉姆萨染色) (2)Microscopy（镜检） (3)other: latex agglutination test(乳胶凝集试验)

Treatment （1）Suramin(苏拉明)：intravenous injection（静注） （2）Quinapyramine(喹嘧胺):subcutaneous injection（皮下注射） （3）Diminazene aceturae(三氮脒)：Subcutaneous injection or deep muscles injection （4）Isometamidium chloride(氯化氮胺菲啶盐酸盐):deep muscles injection （5）锥净 （Chinese medicine）

Prevention (1)control vectors in case of their contact with the hosts (2)limit the activities of recessive infection animals(隐性感染动物) (3)use drugs

Reference 《动物原虫病学》 蒋金书 编著 《兽医寄生虫学》 汪明 编著

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