Fish dishes are very popular because they are diverse, nutritious, tasty and healthy. Japanese cuisine is in fashion, so more and more often on the tables you can see a variety of rolls and sushi, the key element of which is fish, as well as various sea delicacies with sweet and sour sauce. However, meat lovers of the inhabitants of the water depths should be aware that, for all its usefulness, fish can be very dangerous for human health. And now we are talking not about a tropical fugu, whose poison is paralyzed, but about the most common crucian carp, perches and herring. We suggest finding out which parasites in fish are dangerous for humans and how to protect yourself from them. Since fish dishes are often eaten, the information will be useful to everyone.
General information
The parasites that live in fish can also be called helminths, or worms (this name is not entirely true, because worms are only one of the varieties of helminths, but in everyday life the word is used quite often). Their species diversity is amazing and terrifying, but, fortunately, not all species are dangerous to humans.
- Many are interested in whether there are parasites in marine fish? Unfortunately, salt water does not protect its inhabitants from most types of worms. However, most often, residents of muddy stagnant water bodies are infected with helminths, and there is a particularly high risk of encountering sick fish in hot summers.
- The main method of infection is eating raw fish meat; the cyprinid family is particularly dangerous: ides, breams, rudd, carp.
- Most often, helminths dangerous to humans affect herring and cyprinids.
What fish are no parasites? Sterlet is one of the safest. This is the only kind of fish that can be eaten raw. Almost never worms happen in tuna.
Nematodes
Otherwise, they are also called roundworms. The following features are inherent in these fish parasites:
- Length up to 2 cm.
- The shape is spiral.
- They prefer to live in the tissues of marine fish.
- Helminth larvae are dangerous for humans, which are causative agents of diseases (so far no cases of infection of people by adults have been identified).
Nematodes are representatives of the Anisacid family and can cause a serious human disease - anisacidosis.
Trematodes
In science, one more name for trematodes can be found - diagenetic flukes, they enter the human body through fish or other aquatic inhabitants (mollusks, crayfish) and can cause dangerous diseases: opisthorchiasis and clonorchiasis.
Cestodes
Tapeworms, or cestodes, are very common parasitic organisms that can be transmitted through the eaten fish to the human body. They can be recognized by the following signs:
- The length of the larva is up to 2 cm. Adult individuals caught in a favorable environment for themselves - the human body - can grow up to tens of meters.
- Contained in the tissues of both freshwater and marine fish.
The lifespan of certain species in the intestines of the carrier may exceed 20 years.
Comparison of parasite groups
Let us present in the form of a table general information about parasites found in fish that cause harm to humans.
|
Type of parasite |
Nematodes |
Cestodes |
Trematodes |
|
What kind of fish develop in the body |
Cod, flounder, herring, mackerel, halibut, salmon |
Trout, perch, pike, gudgeon |
Representatives of the Karpov family |
|
The method of cooking fish |
Raw, slightly salted, poorly smoked or pickled |
Raw, pickled, undercooked |
Raw, poorly prepared, in violation of the rules |
|
Distribution geography |
China, Japan, Korea, America (North, South), Finland, Sweden, England, France |
Scandinavia, Alaska, Japan, Peru, Chile, Canada, Russia |
Korea, Japan, Vietnam, Laos, Thailand, Philippines, Indonesia |
The table shows that the greatest danger from the point of view of helminth infection is raw fish or poorly prepared, in particular, subjected to a short heat treatment. Worms of various types can be found in both river and sea inhabitants, so you should be especially careful with this product.
The variety of the most popular species
Parasites living in fish and posing a danger to humans are very diverse. A brief description of common ones is presented in the table.
|
Title |
The size |
Description |
Disease caused |
|
Wide ribbon |
Up to 12 m |
Gray body gradually thickening towards the head |
Diphyllobothriasis |
|
Siberian fluke |
Up to 1.2 cm |
White body |
Opisthorchiasis |
|
Chinese fluke |
Up to 1.6 cm |
Rounded white body |
Clonorchiasis |
|
Tapeworm |
1.2 m |
White flat worm |
Ligulosis |
Below we will talk about diseases that cause parasites that have settled in the fish in humans. The names and photos of these helminths would be useful for all lovers of fish, especially dried or slightly salted, not to mention exotic raw fish. But since the spectacle is, to put it mildly, not too pleasant, we can do without such details. We limit ourselves to listing the safest marine life. In the meantime, a little about prevention.
Security measures
In order not to become infected with dangerous parasites (there are a lot of them in fish, as you might already have seen), a person must first abandon the habit of eating raw aquatic meat. Most often it is found in oriental dishes, so despite the desire to enjoy the taste of the delicacy, it is best to abandon it in favor of traditional boiled or fried fish. We highlight some of the recommendations of professionals:
- A complete ban on the addition of raw seafood to the diet.
- Cook fish dishes at a temperature of over 60 ° C for a long time. In this case, all helminths will die.
- Cold smoking, salting do not allow to completely get rid of the parasites existing in the fish, therefore it is undesirable to resort to them.
- Sea fish must be frozen after capture, and then, after thawing, immediately cook. Its storage is highly undesirable.
- River fish should be cooked, boiled (at least 1/3 hours) or steamed, fry.
- Fish pies and pies are baked for at least 30 minutes.
- Meat is best cut into small pieces.
- Advice to housewives: you can not try unprepared fish meat in the cooking process.
It must be remembered that in most cases helminth larvae are not visible to the naked eye, so if a person does not notice them, this does not mean that they really are not.
Dangerous diseases
Parasites in fish that are dangerous to humans can cause a number of serious diseases:
- Clonorchiasis. You can get infected by eating poorly prepared fish: gudgeon, carp, ide. The causative agent is the Chinese fluke. The first signs of the disease are fever, weakness, the appearance of a rash, a medical examination may show an increase in the liver.
- Another serious disease is nanophytosis. It can be obtained if raw meat of taimen, chum salmon, whitefish, gets into the human stomach. The disease can lead to anemia, so parasites should be disposed of as soon as possible.
- Diphyllobothriasis can be caused by parasites that have fallen from the tissues of perch, ruff, pike, salmon. The main manifestations are loss of appetite, impaired stool, nausea, vomiting, irritability, and salivation.
- You can become infected with ligulosis after eating raw fish: hustlers, roaches, bream, roach. With this disease, the parasites in the person gradually grow, poisoning the body of its carrier.
- Anisakidosis is a disease that is very common in Japan, where there is a strong tradition of eating marine predators without prior heat treatment. The presence of larvae in the body can be detected by such signs: a rash on the body, stool disturbance, pain, and vomiting.
- Metagononymosis causes infected meat of trout, whitefish, and crucian carp. Symptoms of the disease appear a week after eating infected fish. This is a fever, a rash accompanied by itching, abdominal pain, diarrhea.
- An opisthorchiasis is caused by a Siberian fluke parasitizing in fish of the cyprinidae family (bream, dace, ide, asp, common carp, silver bream). Interestingly, four-legged predators, especially cats, can be affected by this disease. Its main symptoms include fever, weakness throughout the body, headaches, vomiting, and nausea. Discomfort is worse after eating fatty foods. In the advanced case, it leads to pathologies of the spleen and liver.
As you can see, there are a lot of diseases.
The most dangerous
We offer you to get acquainted with the rating of 10 fish, the most dangerous for humans in terms of the presence of parasites in them.
- Ide. It is in his meat that the parasite characteristic of river fish, such as the Siberian fluke, the main carrier of opisthorchiasis, is most often found. The ingestion of such helminths in the human body leads to damage to the liver, pancreas and nervous system.
- Omul. Often in this delicious gourmet fish there are whole capsules with parasite embryos, so it must be prepared very carefully.
- Roach. Very often it turns out to be affected by the larvae of the tape worm, which causes ligulosis in humans.
- Carp. Like many river inhabitants, it is often infected with Siberian flukes.
- Dace. It is often infected with various types of helminths, both safe for humans and harmful to them.
- Perch. The swollen abdomen of a fish is a sign that it is affected by helminths - carriers of ligulosis or diphyllobothriasis. Often a dangerous pest, diphyllobotrium latum, which, getting into the human body, grows up to 30 (!) Meters, can live in the gills of fish.
- Flounder. This fish should never be eaten raw, otherwise infection with the larvae of the worms is inevitable. It is recommended either to freeze the carcass for at least a week, or cook.
- Tench. Very often this tasty fish is infected with cat fluke, especially if it lives in the rivers of Russia and Ukraine. The ingestion of a parasite in the human body leads to opisthorchiasis.
- Crucian. In these fish, clonorchs, species of trematodes, often inhabit. The most common cases are in the Amur River and its basin. These are popular parasites of river fish, when they enter the human body they cause clonorchosis.
- Hake. When using this fish in raw or slightly salted form, there is a high risk of catching worms. Having become infected with these parasites from river fish, a person becomes ill with anisacidosis. These helminths are also found in marine life. They are dangerous because they are resistant to heat treatment - they can live about 15 minutes at a temperature of +60 ° C.
In no case should this fish be eaten raw, and when cooking it should be boiled or fried for at least 30-40 minutes. Note that the most dangerous are the inhabitants of the ponds - the risk of detecting helminth in these individuals is almost one hundred percent. However, this does not mean that this product must be discarded, it is enough to thoroughly rinse, freeze, and then properly cook such fish. By the way! You can even get infected through kitchen utensils, so the knives, cutting boards and dishes in which such a fish was located should be washed thoroughly, and even better, boiled.
Almost harmless
Parasites in fish (photos of some of them were presented above) are diverse, but those who want to protect themselves and their family are interested in which types of aquatic inhabitants are safer. There is no definite answer to this question - there can be helminths in almost any fish, it depends on its lifestyle. But there are some varieties in which worms are much less common. First of all, they are inhabitants of cold seas, because at low temperatures helminths feel uncomfortable, therefore, northern fish rarely suffer from their presence. Therefore, the following are considered safe:
- mackerel;
- sturgeon;
- catfish;
- tuna.
Parasites in red fish are also found, although not as often as in ide and cyprinids. Therefore, such inhabitants of the waters are classified as moderately safe, as an example we will come:
- trout;
- salmon.
But in these beautiful and tasty inhabitants of the seas, parasites called schistocephamos can reach 2 cm in length. For humans, these worms are practically safe. It is possible to cook from infected fish, however, it is recommended to carefully gut the entrails and subject the meat to lengthy heat treatment.
The name of the fish does not give a full guarantee of the absence of worms, which is why in any case it is necessary to heat the meat. Many parasites living in marine fish are dangerous to humans, so this rule should not be ignored.
And finally, some more useful information.
