Cysticercosis bovis牛囊尾蚴病

08 动医 2 班梁正鹏 吴德鑫 钟露 管光梓 马邦帅

Introduction• Cysticercus bovis is a larval parasite of Taenia

saginata in human body .• Cattle and buffalo are the most important

intermediate host ， and human is only final host of Taenia saginata Goeze.

• It parasites on organs like lungs, liver,brain and all over the muscle tissue, creating mechanical damage even nervous signs.

Morphology( 病原形态 )

Adult parasitizes on human’s small intestine, is ivory and 4-8 meter- long.

• The mature Cysticercus bovis is ovoid, size like soybean and have a ivory cyst, about(7~10)mm×(4~6)mm,filled with liquid,

The front end of worm is smaller and gradually become wider and more flat.

Scolex is about square,1.5-2.0mm in diameter, have no rostellum and hooks, the top is recessed inside. There are 4 suckers like the cup in a scolex, 0.7~0.8mm in diameter,

The neck is long and thin.

• The worm have 1000-2000 segments, each segment has both a set of male and female genital organ. Gravid segments account for one-tenth of total segments, there are a large number of eggs, which are round,tan,36 ～ 42μm in diameter.

Life Cycle （生活史）• The eggs and gravid segment are discharged

with stool. The eggs show a greater resistance to external environment, they can survive 168 days at -4 ,and can survive about 10 days in ℃stool.

• When the intermediate host like cattle eats the polluted feed, developing from egg to Cysticercus bovis after 60-70 days of infection.

• When humans eat these Cysticercus bovis, they grow to adult after 3 months. Adult have long life as 30-60 years in human body.

Epidemiology( 流行病学 )

• Bovine cysticercosis have obvious regional characteristics, some local people like to eat raw beef.

• In severe endemic area, the prevalence of bovine cysticercosis are quite serious.

• Taenia saginata eggs are of strong resistance on the outside environment, survival for 22d in the hay meadow.

• People are only final host of Taenia saginata.

Symptoms( 症状 )

• In general, cattle infected with cysticercus do not show clinical symptoms.

• Human infection with Taenia saginata, can cause digestive dysfunction, can lead to anemia and vitamin deficiency if long existence.

Diagnosis （诊断）• 1 、 Combining with clinical symptoms,

suspected cases are examined positive by IHA 、ELISA.

• 2 、 CT or MRI will help to clinical diagnosis for cerebral cysticercosis.

• 3 、 When pathogen in the subcutaneous nodules biopsy or brain operated pathological tissue was proved, it will be the basis of definitive diagnosis.

Treatment and Prevention （防治）

1. Treatment Praziquantel(吡喹酮 ) Mebendazole(甲苯咪唑 )

2. Comprehensive Prevention

(1) Health education

(2) Feces management(粪便处理 )

(3) Periodic deworming(定期驱虫 )