人体寄生虫学课件：intestinal fluke

1、患者张x，女，5岁，住黄岩市高桥头乡胜利村，6月29日凌晨3时许因发热、腹痛、腹泻，大便很稀似水样伴恶心、呕吐急诊入市第一医院。体检:除急性病容外，无其它阳性体征。T39.6，P120次/分，一般情况好。女孩近几天一直跟家人一起吃饭，无吃不洁食物史，家里其他人没出现类似症状。实验检查：WBC23.5109/L，N82%，L28%，Hb120g/L, 入院诊断为“上感”。住院后进行抗炎治疗和对症处理。 第二天病人呕出一肉红色虫体，能蠕动，背腹扁平，约4015mm。随后粪便直接涂片找到姜片虫卵，确诊为姜片虫病，给予吡喹酮治疗，每公斤体重5mg顿服，7月5日症状消失出院。吡喹酮治疗二个月后大便复查，

2、未找到姜片虫虫卵。成虫鉴定:虫体用布氏固定液处理制成标本后成灰白色，质硬，状如生姜片。标本经浙江省地防所鉴定为布氏姜片吸虫。高桥头乡盛产荸荠、菱角、茭白等水生植物，患儿有生食荸荠、菱角等不卫生习惯，且从未到过外地。据此可确定本例姜片虫病系当地感染，应引起注意。Fasciolopsis buski ( Intestnal fluke) 布氏姜片吸虫 (肠吸虫) Fasciolopsis buski is prevalent in Southeast Asia and lives in intestines of humans and pigs, so it is also called Asia

3、 Giant Intestinal Fluke. The prevalence of fasciolopsiasis is related to growing water plants and feeding pigs on water plants.I. morphology 1. Adult: the body is long elliptic, flesh-colored, looks like a slice of raw meat. The size is about 20-75 8-20 1-3mm, the largest one of human trematodes. Th

4、e ventral sucker (funnel-shaped) is near by the much smaller oral sucker. Two coral-liked testes are located in the posterior half of the body.Adults of F. buski 2. egg is oval in shape, slight yellow in color, 130-14080-85 (the largest helminth egg). The thinner shell with an operculum encloses an

5、ovum and 20-40 yolk cells. Egg of F. buskiEgg of F. buskiEgg of F. buskiEgg of F. buskiand fertilized Ascaris lumbricoidesII. Life cycle 1. Site of inhabitation: small intestine 2. Infective stage: metacercaria 3. Infective mode: eating raw water plants with metacercariae 4. Medium of water plants:

6、water chestnut (荸荠), water bamboo (茭白), water caltrop (菱角), water cabbage(水浮莲) and water hyacinth(水葫芦) 5. Intermediate hosts: Planorbis snail (扁卷螺) 6. Reservoir host: pig 7. Life span: 1-4 yearsMedium of water plantswater bamboo water caltropwater chestnutPlanorbis snail Life Cycle of Fasciolopsis b

7、uski attach to the intestinal wall adolescent adults eggs excystation takes place in the duodenum In Human Body Discharged man eats raw water plants with matacercariae in fecesmetacercariae Eggs get into water adhere to the surface 26-32 of water plants 3-7weeks In the Fresh Water Miracidia hatche i

8、nvadeCercariae Planorbis snail Escape from the snail asexual reproduction Cercariae Daughter rediae Mother rediae SporocystsIII. Pathology and Symptomatology 1. Enteritis due to the attachment of the adults manifests abdominal discomfort, nausea, vomiting and diarrhea ( watery diarrhea). 2. Malnutri

9、tion results from the worms sharing food with the host and diarrhea . Manifests anemia, edema of leg and face even ascites. IV. Diagnosis Stool examination: 1. Direct fecal smear is the first choice method. 2. Water sedimentation method V. Treatment and Prevention 1. The treatment of the patients, c

10、arriers and pigs Drug of choice is praziquantel. Other effective drugs include hexachloroparaxylol, bithionol (bitin). 2. Prevention (1) Health education, (2) Deal with night soil. (3) Avoid feeding pigs on raw water plantsVI. Epidemiology This disease is prevalent in Southeast Asia. In China it is found in 18 provinces, city and autonomi