Hepatic fluke is a parasitic worm belonging to the class of diagenetic flukes (trematodes). Infection is possible by eating infected freshwater fish in raw or poorly prepared form. The parasite can live on aquatic plants, for example, on some types of watercress, also eaten. After entering the gastrointestinal tract, flukes move from the intestine to the bile ducts of the liver, where they begin to grow. The infection can be completely asymptomatic, but often the liver fluke causes disorders of the biliary system, including the bile ducts of the liver and the gall bladder. Although infection in this worm (fascioliasis) is quite rare in developed countries, the fact remains: the disease is periodically diagnosed, and mainly among people traveling to regions where similar parasites are most common.
What is fascioliasis?
Initially, the disease was known only to veterinarians, and a dangerous worm called Fasciola hepatica primarily affected cattle in South Africa. Cows, goats and sheep were carriers of adult fluke that lay eggs in water. Worms from the juvenile stage of development hatched from eggs. Young hepatic hepatic infects certain types of slugs living in water bodies, and grew, gradually moving to plants (for example, watercress), where it was eaten along with greenery by domestic animals grazing in the area. The worms gnawed through the intestinal walls and remained in the liver, where they reached adult forms of development and began to lay eggs. Human fascioliasis is the same cycle, only in the human body.
Infection
Liver fluke (see photo in the article) is a danger to those who eat raw or poorly fried (undercooked) freshwater fish, as well as raw plants on whose leaves parasites live. Among these plants are watercress, wild mint, dandelions, pistachia and some other representatives of the flora, growing in water or along the banks of ponds and used to make fresh salads. In rare cases, a person can catch an infection due to the use of contaminated water.
Simply rinsing the edible leaves with water does not protect against parasite larvae, however, they die during the preparation and washing of plants with 6% acetic acid or potassium permanganate.
Infection by eating meat from infected animals is not possible.
Symptoms
If a person has caught a parasite such as hepatic fluke, infection symptoms may be completely absent. However, in most cases, patients report unusual signs of pathology within a month after eating exotic dishes containing water plants or raw fish. At this stage of the disease, the symptoms are primarily associated with the process of penetration of the worm into the liver. Moving the fluke may be accompanied by fever, itching, abdominal pain, skin rash, and even coughing. As soon as the worm reaches the adult stage of development in the liver, the signs of pathology become similar to the symptoms of blockage of the biliary tract. Abdominal pain is more associated with pain caused by gallstones. Jaundice appears, and the bile ducts become more vulnerable to infection - cholangitis. Almost always there is weakness, lethargy, loss of appetite, weight loss.
An adult hepatic hepatic can live in the human liver for twelve years, but even after the death of the parasite, the symptoms will most likely persist due to damage to the bile ducts. Fatal outcome of the disease is extremely rare.
Diagnostics
At an early stage of fascioliasis, the human immune system responds to infection by a change in the number of white blood cells - eosinophilia, which makes it possible to establish a presumptive diagnosis. An ultrasound scan, like a scan of internal organs using computed tomography (CT), allows you to track the path of movement of the worm inside the liver. Even if the parasite has already settled on a specific site of the bile duct, damage to the intestines and liver will still be visible on an ultrasound scan. In addition, if a hepatic fluke is suspected, they look for worm eggs in the feces. There are also specific studies aimed at checking the response of the immune system to the presence of a parasite, but not all clinics can afford such an expensive diagnosis.
Treatment
To get rid of the parasite is quite simple - you need to take a single dose of a drug called "Triclabendazole". Unfortunately, it is not available for purchase in the countries of South Africa, where local residents and tourists most often turn to doctors complaining about the characteristic symptoms of fascioliasis, but upon confirmation of the diagnosis it is possible to arrange an individual delivery of the medicine. Experts also recommend that you observe bed rest and adhere to a diet rich in animals and vegetable proteins. You may need to take extra vitamins and iron supplements.
In advanced cases, when severe fascioliasis is diagnosed and an active adult hepatic fluke is diagnosed, the treatment may consist of a surgical operation to remove the harmful parasite using endoscopic retrograde cholangiopancreatography.
Prevention
- Soak water plants in a 6% solution of acetic acid or in potassium permanganate for 5-10 minutes.
- Vegetables growing in water should be carefully boiled before use.
- Watch the cleanliness of the areas where edible plants grow; their pollution by wastewater must not be allowed.
- Treat sheep and cattle if the veterinarian has diagnosed fascioliasis. For the treatment of animals, a single dose of Triclabendazole is also used.
Scientists are currently working on a vaccine against fascioliasis.