Does pike have opisthorchiasis? This question is of interest to many lovers of fish dishes. After all, it is very easy to get parasitic invasion through food. Pike is a healthy and tasty fish. However, the inhabitants of fresh water bodies are very often infected with dangerous types of helminths. Is it possible to become infected by eating pike dishes? Let's try to figure it out.
What it is
Before answering the question: “Does the pike have opisthorchiasis?”, It is necessary to understand the development mechanism of this dangerous helminthic invasion.
Opisthorchiasis is a severe parasitic disease that occurs with damage to the liver, gall bladder and pancreas. Its causative agent is cat fluke (hepatic fluke). This is a helminth that belongs to the class of flatworms. On the body of the worm there are special suction cups with which it is attached to the internal organs of the host.
Opisthorchiasis affects not only fish and people, but also mammals. Stray cats and dogs that live near ponds can be infected with a hepatic trematode, and the insidiousness of this pathology lies in the fact that a person can have an invasion for a very long time without obvious manifestations. Symptoms of opisthorchiasis appear in the late stage of the disease, when there is a severe dysfunction of the internal organs.
Life cycle
To understand whether pike has opisthorchiasis, you need to know how the cat fluke propagates and develops. This worm goes through a rather complex life cycle, during which the helminth changes its owners:
- Infected mammals and humans secrete parasite eggs along with feces.
- Then the eggs fall into the water. They penetrate the body of mollusks and turn into larvae (cercariae). This stage of development of the helminth is not dangerous to humans.
- Many fish species feed on mollusks and become infected with opisthorchiasis. In their body, the larva turns into metacercaria. It is at this stage that the helminth becomes dangerous to humans.
- People become infected by eating fish with opisthorchiasis. In the human body, the larva becomes an adult sexually mature worm and begins to parasitize on the internal organs. Sick people produce eggs with feces. After this, the helminth life cycle is repeated again.
Opisthorchiasis may be asymptomatic for many years. Then a person has skin itching, weakness, intestinal upsets, pain in the right side under the ribs. These are signs of damage to the liver and pancreas.
Infection pathways
Contrary to popular misconception, a person cannot become infected with opisthorchiasis from sick cats and dogs. Also, people cannot get invasion by accidentally swallowing water from a pond or river. The only way to infect humans with cat fluke is to eat infected and poorly processed fish.
Do pike and perch get opisthorchiasis? This invasion is more susceptible to fish of the Karpov family. However, both pike and perch are predators. They eat shellfish and small fish and may well become infected with opisthorchiasis.
Often fishermen ask the question: "Is there an opisthorchiasis in the river pike?" Any freshwater fish that feeds on mollusks can become infected with cat fluke larvae. Invasion is not found only in the inhabitants of sea waters. Both pond and river pikes are equally affected by this disease.
Disease prevalence
In some regions of Russia there is a high incidence of opisthorchiasis. A large degree of infection of fish and shellfish is observed in the basins of the following rivers:
- Northern Dvina.
- Kama.
- Volga.
- Yenisei.
- Turquoise.
- Obi.
- Irtysh.
- Ural.
- The Dnieper.
- Don.
These rivers are considered epidemiologically unfavorable for opisthorchiasis. When consuming fish caught in the above bodies of water, special care must be taken.
Signs of fish invasion
To understand whether pike have opisthorchiasis, you need to carefully look at the appearance of the fish. The following symptoms may indicate infection with larvae:
- turbidity and excessive dryness of the eyes;
- too easy discharge of scales;
- mucus on the body;
- bloating of the abdominal region;
- unpleasant odor from the entrails when cutting fish;
- swamp color of gills.
The muscles of infected individuals become excessively soft. You can try clicking on the body of the fish. If a deep fossa remains on the scales, then, most likely, the pike is infected with larvae.
Can the pathogen opisthorchiasis be seen with the naked eye? Where is the largest accumulation of larvae? Metacercariae are localized in the muscles and subcutaneous tissue of fish. However, it is impossible to examine them without a microscope, since the larvae are extremely small. Therefore, fish infection can only be judged by indirect signs.
How to get rid of larvae in fish during its preparation? Let's consider this question in more detail.
Heat treatment
Do pike have opisthorchiasis and is it possible for them to become infected if the fish has been carefully boiled or fried? Such a product can be dangerous if the heat treatment was insufficient. Cat fluke larvae die only under prolonged exposure to high temperatures.
To avoid infection, you must follow the following rules for preparing fish:
- Before frying, you need to cut the pike into small pieces. This will ensure uniform heat treatment and help completely get rid of live larvae. Fry fish for at least 20-30 minutes. This time is enough to destroy metacercariae. When frying pike, the pan must be covered with a lid.
- When cooking, fish should be boiled for at least 30 minutes. During this time, all parasites in the muscles die. Large pike need to be cut into slices before boiling.
- It is not recommended to bake a whole carcass of pike. Better to cut it into pieces beforehand. Fish should be kept in a preheated oven for at least 1 hour.
- The safest way to cook pike is stew. Keep the fish on low heat until its bones are soft. Only in this case can one be sure of the complete destruction of the larvae.
Caviar
Can the pathogen of opisthorchiasis be in the pike caviar? Such a product may also be infected with larvae. Metacercariae are able to penetrate from the muscles of fish into eggs, and then transmitted to humans.
To destroy parasites in pike caviar, it is necessary to carefully salting the product. Do not use quick cooking recipes. In the "five-minute" caviar, a huge amount of live fluke larvae can remain. A sufficient amount of salt should be put in a jar with the product - about 2 tablespoons per 800 ml capacity. Salted caviar must be kept in the refrigerator for at least 5 to 7 days before use.
Before cooking, it is recommended to boil caviar for 2 minutes in salt boiling water or keep it in the cold for 5-10 days at a temperature of -4 to -12 degrees. This will also help get rid of the larvae.
Salting
If the correct salting technology is violated, the fluke larvae may remain in the pike. With this method of preparation, it is very important to observe the correct proportions of the products. 10 kg of pike will require 2 kg of salt.
Fish should be laid out in layers and sprinkled with plenty of salt. Small pike must be kept in brine for about 5-7 days, and large - at least 14 days. Only in this case the product will be safe.
Frozen fish
Does pike have opisthorchiasis if the fish was well frozen? The parasite larvae are quite resistant to low temperatures. To get rid of metacercariae, you need to keep the fish in the cold for at least 18-20 days. In this case, the temperature should not be higher than -12 degrees. In frosts of -30 degrees, it is enough to withstand a pike for about 3 days. However, even after such preparation, the fish must be thoroughly processed.
In no case should you eat stroganin - frozen raw fish cut into thin slices. This is a very dangerous product. Staying fish in the cold does not always lead to the death of parasites.
Smoking and drying
The causative agent of opisthorchiasis in pike can persist with cold smoking. Therefore, this type of fish is best dried. Before processing, the pike should be thoroughly frozen, salted and aged for 3 days. Only after this, you can start drying, which should last at least 20 days.
When cooking pike delicacies, preference should be given to the hot smoking method. This treatment of fish reliably destroys the larvae.
Other parasite species in pike
Cat fluke is far from the only pike parasite. The following helminths can also be found in predatory species of freshwater fish:
- Chinese fluke. This worm also belongs to the group of flukes. It causes a disease - clonorchiasis. Signs of invasion are very reminiscent of manifestations of opisthorchiasis. The parasite is localized in the liver. This leads to a strong enlargement of the organ, pain on the right side under the ribs, and skin itching.
- Wide ribbon. This tapeworm can reach sizes up to 10-12 m. It parasitizes in the intestines and causes a disease - diphyllobothriasis. Invasion is accompanied by sharp weight loss, dyspeptic symptoms and weakness.
- Anisakide. This is a very dangerous type of parasite. It enters the human body when eating poorly processed fish. Anisakidosis is accompanied by severe gastrointestinal disorders and allergic reactions. To date, no effective treatment for this invasion has been developed.
- Nanofietus. This flatworm can enter the body not only through food. Its larvae can remain in the hands of humans after cutting fish. Nanofietus causes inflammation and irritation of the intestines. However, after 1-2 months, self-healing usually occurs, since the helminth's life cycle is very short, and it is not able to reproduce in the human body.
Opisthorchiasis in other fish species
As already mentioned, any species of freshwater fish can be infected with opisthorchiasis. Invasion is most often found in representatives of the carp family:
- crucian carp;
- bream;
- carps;
- common carp.
Also, perch, ide, ruff and peled are often infected with cat fluke. If the above fish species live in epidemiologically disadvantaged reservoirs, then in 90% of cases they have opisthorchiasis.
How to avoid invasion
The only way to prevent opisthorchiasis in humans is through careful processing and proper preparation of pike. If the fish looks sick, then it is better to refuse to eat it.
It is also necessary to thoroughly rinse the cutting board and utensils in which the raw fish was. Cat fluke larvae can be stored on kitchen utensils.
In no case should you feed raw freshwater fish to pets. As already mentioned, a person cannot be infected with fluke larvae from other mammals. However, in cats and dogs, opisthorchiasis is very difficult and often ends in the death of the animal. Feeding your pet raw fish, you expose its health and life to serious danger.