Trematode Infection Treatment & Management

Updated: Feb 19, 2019
  • Author: Subhash Chandra Parija, MD, MBBS, PhD, DSc, FRCPath; Chief Editor: John L Brusch, MD, FACP  more...
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Medical Care

Causes of mortality include recurrent pyogenic cholangitis in persons with schistosomiasis; hemiplegia, cephalgia, and paresis in those with cerebral paragonimiasis; cholangiocarcinoma in those with clonorchiasis; and intercurrent bacterial infections in those with fascioliasis and/or intestinal fluke infections.

Praziquantel remains the drug of choice for all trematode infections except fascioliasis, for which triclabendazole is the drug of choice. [45]

Triclabendazole was approved in the United States in 2019 for fascioliasis in patients aged 6 years or older after being available from the CDC for many years. [46] The drug works by preventing the polymerization of the molecule tubulin into the cytoskeletal structures and microtubules. However, resistance of F hepatica to triclabendazole has already been recorded in Australia and Ireland. Artemether has been shown to be effective in a rat model of fascioliasis.

Based on limited data from the CDC, nitazoxanide might be effective therapy in some patients with fascioliasis. Bithionol, a halogenated phenol previously used as a first-line agent for the treatment of fascioliasis in the United States, is no longer available. Praziquantel, which is active against most trematodes (flukes), is typically not active against Fasciola parasites. Therefore, the CDC does not recommend praziquantel therapy for fascioliasis. [47]

Emetine, dehydroemetine, chloroquine, albendazole, and mebendazole were once used in many trematode infections; however, this practice is now discontinued because these drugs are associated with toxicity and their efficacy is in doubt.

When trematode infections are complicated by intercurrent bacterial infections, institute antibiotic therapy.


Surgical Care

Surgical management may be needed for complications of trematode infection, which include bladder carcinoma in patients with urinary schistosomiasis, fibrosis and thickening of the intestinal wall in those with intestinal schistosomiasis, ascending cholangitis in those with fascioliasis, and cholangiocarcinoma in those with clonorchiasis.

Schistosomicidal drugs, steroids, and surgery are the currently available treatments for neuroschistosomiasis. [18] A multidisciplinary approach is warranted for effective treatment of schistosomiasis. [48]



The following consultations may be necessary:

  • Intestinal and liver trematode infections - Infectious diseases specialist

  • Urinary schistosomiasis - Infectious diseases specialist, gastroenterologist, and urologist

  • Pulmonary paragonimiasis - Chest disease specialist

  • Ectopic fluke infections (eg, abdominal and cerebral paragonimiasis; ectopic schistosomiasis in intestine, lung, brain, or spinal cord; ectopic clonorchiasis) - Consultations with appropriate specialists as required per particular manifestations



To prevent paragonimiasis and clonorchiasis, avoid eating raw or undercooked fish.

To prevent infection with intestinal flukes and fascioliasis, properly clean and thoroughly wash raw vegetables, watercress, and other water-grown vegetables before eating.

Cook water-grown vegetables thoroughly before eating.



The patient should be given adequate bed rest supplemented with an adequate protein-rich diet.



Note the following practices for deterrence and prevention of trematode infection:

  • Elimination of molluscan hosts using molluscicides, such as metal salts, and organophosphates or carbamates to control infection with schistosomes and intestinal, liver, and lung flukes

  • Proper sanitary disposal of human and pig excreta to avoid water contamination

  • Chemotherapy of infected persons

  • Avoidance of consumption of contaminated water, water plants, fruits, fish, crab, and raw liver

  • Thorough cleaning and washing of raw vegetables and aquatic fruits to prevent infection with intestinal flukes

  • Thorough cooking of water-grown vegetables before eating

  • Cooking of crab and crayfish before eating to prevent infection with lung flukes


Further Outpatient Care

Further outpatient care includes health education. Thorough cooking of fish and aquatic vegetables, fruits, and plants is necessary to prevent ingestion of infective forms of the parasite.


Further Inpatient Care

Anemia may be treated with iron supplements and vitamins, which may be administered orally to facilitate iron absorption.



Transfer if access to specialized health care services is lacking.