后睾吸虫病OpisthorchosisSpeaker ： Debbie Zhong

谭永锋 200830330522张 冰 200830330527钟思昕 200830330528

Opisthorchosis• The pathogen of Opisthorchosis is

Opisthorchis felineus ( 猫后睾吸虫） and O.viverrini( 麝猫后睾吸虫 )of Opisthorchiidae （后睾科） .

• parasitizing in bile duct of the liver of human and pigs, dogs and cats

• Wild animal • This disease cause greater harm to Cats

and Dogs• zoonotic trematodes,le

1.病原形态 Morphology (1)Parasites Opisthorchosis sp. is morphologically simillar to the Clonorchis sinensis （ 形 态 上 与 华 枝 睾 吸 虫 相

似 ） . Length 8-12 mm, width 2-3 mm. Flat leaf-shaped, narrow, slightly pointed front end. Oral sucker is slightly larger than ventral sucker which is located in front 1 / 5 of the body. Two large dendritic （ 分 支状 ） testes locate in tandem （串联 ） in the back of the worm. Lobulated （ 分 叶 状 ） ovary lies before the testis, between the one large spermathecae （ 受 精

囊）and front testis.

Oral sucker

Ventral sucker

testis

ovary

Uterus

spermathecae

Clonorchis sinensis egg （ 2 ） Eggs• Tiny•27-35×12-20μm•Tawny黄褐色•Bulb-like•Miracidium(in egg)•内含毛蚴•Operculum (above)•上端有卵盖•Protuberance(behind) •下端有一小突起

Life Cycle

Opisthorchis sp. parasitizes in the bile duct of cats or dogs, then lay eggsinto bile, and let out through digestive tract.

后睾吸虫寄生于犬猫胆管，并在其内排卵，经胆汁流入小肠再随消化道排出

The eggs will be eaten by the first intermediate host, Bithynia leachii,then turn into miracidium （毛蚴） .

A month later they grow into sporocyst ( 胞蚴 ) with redia （雷蚴） ,then turn into cercaria （尾蚴）in another month and flee away,swim in the water.

miracidium

Cercaria

When they meet the second inter-mediate host, fish, they squeeze inthe body of their host and grow intometacercaria( 囊蚴 ) in subcutaneousfat or muscle. The metacercaria become mature in 6 weeks.

When eaten by cats or dogs, the larva( 幼虫 ) enter liver through bile duct. Then turn into adult( 成虫 ).

Epidemiology

The definitive hosts of Opisthorchis is Dog/Cat/ Fox, Marten 貂 , Lutra 水獭

/Lion/ Pig and even Human.

Their eggs can survive in water for a long time. When in a 19°C condition, they can survive for at least 70 days. The infection rate can be 100% in cats and 90% in dogs in specific areas.

Symtom

• Mild infection : No obvious clinical symptoms

• Severe infection: Systemic jaundice 全身性黄疸

• depression 抑郁 , loss of appetite 食欲不振 ; sometimes vomiting 呕吐 , constipation 便秘 or diarrhea 腹泻 , graduate emaciation 消瘦 and obvious ascites 腹水 .

Diagnosis

• In vivo examination 活体检查 : Sedimentation method 水洗沉淀法 and Zinc Sulfate flotation method 硫酸锌漂浮法 .

• Postmortem examination : Parasites 虫体can be found in bile dust at liver by dissection 解剖

LesionsIt can be seen dendritic （分支状） from ERCP( 内镜逆行胰胆管造影 )

Treatment & Prevention

Treatment:1.Praziquantel 吡喹酮 ： Preferred, 10-35 mg/kg, 5-7 days interval after the first oral taking. 第一次服用后间隔 5-7 日再服第二次2.Albendazole 丙硫咪唑 :25-50 mg/kg, Oral, Once per day, Keep taking for 2-3 daysPrevention: Dogs and cats should be fed with thoroughly cooked fish or frozen fish.