Trematodes are commonly referred to as flukes. This term can be traced back to the Old English name for flounder, and refers to the flattened, rhomboidal shape of the worms.
The flukes can be classified into two groups, on the basis of the system which they infect in the vertebrate host.
The flukes can be classified into two groups, on the basis of the system which they infect in the vertebrate host.
- Tissue flukes infect the bile ducts, lungs, or other biological tissues. This group includes the lung fluke, Paragonimus westermani, and the liver flukes , Clonorchis sinensis and Fasciola hepatica.
- Blood flukes inhabit the blood in some stages of their life cycle. Blood flukes include species of the genus Schistosoma. 1
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Clonorchis sinensis
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Fasciola hepatica
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Eurytrema pancreaticum
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Table
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Life Cycle
Treatment
Treatment Information 6
Praziquantel, adults, 75mg/kg/day orally, three doses per day for 2 days; the pediatric dosage is the same. Praziquantel should be taken with liquids during meals.
Alternative:
Albendazole* is an alternative drug; the dosage for adults is 10mg/kg/day for 7 days. The pediatric dosage is the same. Albendazole should be taken with food; a fatty meal increases the bioavailablility.
The following dosages are suitable for adults and children over 4 years.9
A single dose of 25 mg/kg is recommended for intestinal fluke infections.
A dose of 25 mg/kg three times a day for 2 consecutive days produces virtually 100% cure rates in the majority of liver and lung fluke infections. A single dose of 40 mg/kg has also been shown to be effective.
Larger doses are required for eradication of Fasciola hepatica, but no firm recommendations can be offered on the basis of currently available information.
Treatment Information 6
Praziquantel, adults, 75mg/kg/day orally, three doses per day for 2 days; the pediatric dosage is the same. Praziquantel should be taken with liquids during meals.
Alternative:
Albendazole* is an alternative drug; the dosage for adults is 10mg/kg/day for 7 days. The pediatric dosage is the same. Albendazole should be taken with food; a fatty meal increases the bioavailablility.
The following dosages are suitable for adults and children over 4 years.9
A single dose of 25 mg/kg is recommended for intestinal fluke infections.
A dose of 25 mg/kg three times a day for 2 consecutive days produces virtually 100% cure rates in the majority of liver and lung fluke infections. A single dose of 40 mg/kg has also been shown to be effective.
Larger doses are required for eradication of Fasciola hepatica, but no firm recommendations can be offered on the basis of currently available information.
Fact
囊蚴在90摄氏度的热水里只需要1秒钟就会死亡,在60-70摄氏度的热水里也活不过十几秒钟;
把含有囊蚴的鱼肉放在负20度冷冻3天以上,便会完全失去感染力,但在4度冷藏条件下,囊蚴的感染力能够维持半年以上;
蒜汁在体外实验中有一定杀灭肝吸虫囊蚴的作用,不过作用较弱,需要4到6个小时才能完全杀灭囊蚴
很多宠物和家畜也能感染肝吸虫,比如猫,狗和猪等,这些动物被称为保虫宿主。它们感染后不但会生病,还会到处排放虫卵,严重威胁人民群众的健康
肝吸虫的成虫寿命很长,可以达到20~30年。由于肝吸虫无法直接在人类体内完成全部生命周期,所以人类感染成虫的数量取决于吃下去的鱼体内含有的囊蚴的数量。5
囊蚴在90摄氏度的热水里只需要1秒钟就会死亡,在60-70摄氏度的热水里也活不过十几秒钟;
把含有囊蚴的鱼肉放在负20度冷冻3天以上,便会完全失去感染力,但在4度冷藏条件下,囊蚴的感染力能够维持半年以上;
蒜汁在体外实验中有一定杀灭肝吸虫囊蚴的作用,不过作用较弱,需要4到6个小时才能完全杀灭囊蚴
很多宠物和家畜也能感染肝吸虫,比如猫,狗和猪等,这些动物被称为保虫宿主。它们感染后不但会生病,还会到处排放虫卵,严重威胁人民群众的健康
肝吸虫的成虫寿命很长,可以达到20~30年。由于肝吸虫无法直接在人类体内完成全部生命周期,所以人类感染成虫的数量取决于吃下去的鱼体内含有的囊蚴的数量。5
Fasciola hepatica
Infective Fasciola larvae (metacercariae) are found in contaminated water, either stuck to (encysted on) water plants or floating in the water, often in marshy areas, ponds, or flooded pastures. People (and animals) typically become infected by eating raw watercress or other contaminated water plants. The plants may be eaten as a snack or in salads or sandwiches. People also can get infected by ingesting contaminated water, such as by drinking it or by eating vegetables that were washed or irrigated with contaminated water. Infection also can result from eating undercooked sheep or goat livers that contain immature forms of the parasite. 2
肝片吸虫_百度百科
牲畜饮水或吃草时吞进囊蚴即可感染。囊蚴在肠内破壳而出,穿过肠壁经体腔而达肝脏。牛羊的肝脏胆管中如被肝片吸虫寄生,肝细织被破坏,引起肝炎及胆管变硬,同时虫体在胆管内生长发育并产卵,造成胆管的堵塞,影响消化和食欲;同时,由于虫体分泌的毒素渗入血液中,溶解红血细胞,使家畜发生贫血、消瘦及浮肿等中毒现象。人体感染可能是食生水、生蔬菜所致.因此在牧场中应改良排水渠道,消灭中间寄主锥实螺,禁止饮食生水、生菜,可使人免受感染。
Life Cycle
Treatment
- Human fascioliasis can be easily treated with a single dose of a drug called triclabendazole. 3 10mk/kg single dose , or two-10mg/kg doses separated by 12-24 hours 7
- 7.三氯苯唑(Triclabendazole、Fasinex、肝蛭净) 本品为瑞士汽巴加基公司生产,为新型苯并咪唑类驱虫药,对各种日龄的肝片吸虫均有明显杀灭效果。内服,牛12mg/kg·次,羊、鹿10mg/kg·次。8
- Praziquantel is NOT effective for fasciola hepatica. 4
Fact
How are humans infected?
Is it safe to eat commercial ready-to-use salad plants?
Is it safe to eat ‘organic’ salad plants?
How are humans infected?
- Humans are infected when they eat plants that have the parasite attached to the leaves. The plants most commonly include watercress, but wild or aquatic mint, dandelion leaves, waterblommetjie, water lettuce and potentially other aquatic and semi-aquatic plants used in salads have been implicated. Much less commonly, humans may be infected when they drink contaminated water.
- Simple rinsing of the plants does not always remove the parasite, however cooking will destroy the parasite and rinsing the plants in 6% acetic acid, or potassium permanganate, for 5-10mins will inactivate the parasite.
- You cannot get the infection from eating the meat of infected animals.
Is it safe to eat commercial ready-to-use salad plants?
- Most commercial watercress and other salad plant production is in irrigated tunnels and is considered to be free from liver fluke contamination.
Is it safe to eat ‘organic’ salad plants?
- ‘Organic’ watercress or other raw salad plants, if they are harvested informally or in the wild, are a risk, as animal contact with water and snails cannot be reliably prevented.
- Commercial pesticide- and chemical-free ‘organic’ salad plants are not a risk, if produced under safe conditions. 3
Eurytrema pancreaticum is usually found in the pancreatic ducts of hogs in south China and of herbivores such as cattle, sheep, goats, monkeys and camels in the Orient and Brazil. True infection in humans has been reported in China and Japan. 11
病原:胰阔盘吸虫(E. pancreaticum)、腔阔盘吸虫(E coelomaticum)和枝睾阔盘吸虫(E.llonorchis),寄生于牛羊等胰管内引起的一种人兽共患病。
流行特点:需陆地蜗牛作第一中宿主,需草螽和针蟋作第二中宿主。发育无雷蚴阶段。从虫卵到成虫整个发育周期需500~560d,越冬二次。成虫在终宿主绵羊体内可存活达7年以上。
Clinical signs and Necropsy:虫体的机械性刺激和毒素作用,引起胰管发炎、增粗,管壁增厚,管腔狭或阻塞;若发炎并带入细菌则化脓,无细菌可形成囊肿。严重者胰脏功能失常,患畜消化机能障碍,营养不良,消瘦、贫血,粘膜苍白;拉稀;颌下水肿等。重者可因恶病质而死亡。
Diagnosis: 粪检查到虫卵或剖检在胰管等处查到虫体可确诊。10
Treatment:
1.血防846:羊0.4~0.6g/kg,牛0.3g/kg,隔天一次,连用3次。绵羊耐受性﹥山羊。
2.吡喹酮:羊90—100mg/kg po.或羊30—50 mg/kg,牛35—45 mg/kg,腹腔注射。
3.可试用丙硫咪唑。10
Praziquantel is the drug of choice, and the same dosage is recommended as that used for infection with Opisthorchis infection. Triclabendazole, an imidazole derivative, may also be effective.
Garcia, L.S. 2007. Diagnostic Medical Parasitology, 5th ed., ASM Press, Washington, D.C. 11
Control:
Because infection in humans is usually accidental, few preventive measures are effective. Use of wild herbs and grasses as food can be avoided unless they are carefully washed. Crickets or grasshoppers could also be accidentally ingested if they were within plant material that had not been carefully washed. 11
12
表14-1 我国常见寄生人体吸虫的分类与其主要寄生部位
复殖目 Digenea | 后睾科 Opisthorchiidae | 支睾属 Clonorchis | 华支睾吸虫 C.sinensis | 肝胆管 |
异形科 Heterophyidae | 异形属 Heterophyes | 异形异形吸虫 H.heterophyes | 肠管 | |
片形科 Fasciolidae | 姜片属 Fasciolopsis | 布氏姜片吸虫 F.buski | 小肠 | |
片形属 Fasciola | 肝片吸虫 P.hepatica | 肝胆管 | ||
并殖科 Paragonimidae | 并殖属 Paragonimus | 卫氏并殖吸虫 P.westermani | 肺(或脑) | |
狸殖属 Pagumogonimus | 期氏狸殖吸虫 P.skrjabini | 皮下(或肝) | ||
裂体科 Schistosomatidae | 裂体属 Schistosoma | 日本裂体吸虫 S.japonioum | 门脉系统 | |
棘口科 Echinostomatidae | 棘隙属 Echinochasmus | 日本棘隙吸虫 E.japonicus | 小肠 |
Reference
1. Trematoda - Wikipedia, the free encyclopedia link
2. CDC - Fasciola link
3. National Institute for Communicable Diseases | Alerts | FAQs About Liver Fluke Disease (fasciola Infections, Or Fascioliasis) link
4. Principles and Practice of Infectious Diseases - John Eugene Bennett, Raphael Dolin, Martin J. Blaser - Google Books link
5. 下次把鱼做熟了再吃 | 日志 | 果壳网 科技有意思 link
6. CDC - DPDx - Clonorchiasis link
7. CDC - DPDx - Fascioliasis link
8 肝片吸虫病 link
9. WHO - Helminths: Intestinal, liver and lung flukes: Praziquantel link
10. 第十章 反刍动物寄生虫病-兽医吧 link
11. Dicrocoelium dendriticum, Dicrocoelium hospes, Eurytrema pancreaticum (Pathogen – Less Common Liver Trematodes) -para-site online link
12 Eurytrema Pancreaticum-Prezi link
1. Trematoda - Wikipedia, the free encyclopedia link
2. CDC - Fasciola link
3. National Institute for Communicable Diseases | Alerts | FAQs About Liver Fluke Disease (fasciola Infections, Or Fascioliasis) link
4. Principles and Practice of Infectious Diseases - John Eugene Bennett, Raphael Dolin, Martin J. Blaser - Google Books link
5. 下次把鱼做熟了再吃 | 日志 | 果壳网 科技有意思 link
6. CDC - DPDx - Clonorchiasis link
7. CDC - DPDx - Fascioliasis link
8 肝片吸虫病 link
9. WHO - Helminths: Intestinal, liver and lung flukes: Praziquantel link
10. 第十章 反刍动物寄生虫病-兽医吧 link
11. Dicrocoelium dendriticum, Dicrocoelium hospes, Eurytrema pancreaticum (Pathogen – Less Common Liver Trematodes) -para-site online link
12 Eurytrema Pancreaticum-Prezi link