Everyone knows that as a food product, fish is much healthier than meat. In addition, it is very easily and quickly absorbed by the body. Besides, fish is really very tasty. And there are many ways to prepare it, enough so that this product does not get boring. Recently, exotic dishes made from fish that are not subjected to salting or heat treatment have become very widespread. But not everyone knows that fish is also a source of many parasites, which, under certain conditions, can settle in the human body and, to one degree or another, affect his health.
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Many lovers of fish - dried, dried, smoked - have seen the presence of one or another type of parasite in it. Are red worms in fish, which are quite common and look very scary, dangerous for humans? And are there species of fish where worms are completely absent? Let's try to figure it out.
Worms in fish: how harmful they are to humans and their bodies
Let's start with the fact that not every worm that has found refuge in fish is harmful and dangerous to human health, although there are a lot of fish worms in nature. If you notice red worms in fish meat, be very careful and try to remove them as much as possible before you start cooking.
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According to recent research in this direction, it has been established that almost all commercial fish are invasive. Even sea fish are susceptible to this scourge, although many mistakenly consider it safe due to the high salt content in sea water. Marine fish contain anikasids, cestodes and a number of other types of fish helminths, as well as nematode roundworms or flat flukes. What to do if worms are found in red fish. What to do? It is better to return such fish to the seller, but you can also subject it to thorough heat treatment or freezing. In this case, up to 99% of helminths die. But first try to remove worms from the fish meat and its intercostal space, since even completely safe worms are very unpleasant to eat.
In almost all known cases, red worms are present in fish. These parasites are considered the most common and widespread. They feel great in any fish, localizing in the intestines, intercostal spaces, gills, muscles, tail part and even in the eyes. They live for a very long time and are quite resistant to weak heat or salt treatment. Poorly fried and lightly salted dishes can bring a lot of trouble and serious health problems. Moreover, these parasites can remain in the human body for quite a long time - some species can spoil your health for about forty years.
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True, with proper heat treatment, red worms in fish become harmless. But it is better to do without this kind of experiment, because poisoning can have very serious consequences. The most dangerous are very small red worms that are located in the muscles of the fish. Quite often, such unpleasant surprises began to be discovered among the inhabitants of natural bodies of water. While in previous years cases of fish infestation with parasites were very rare, one might say isolated, nowadays red worms in fish are found alarmingly often. Whether the ecology or the influence of space is to blame for this is not important for the average person. It is important to know in which fish you can find helminths that are dangerous to your health.
Classification of worms and their description
Infection of fish with various parasites, not only red ones, is an almost universal phenomenon. The most common classes of parasites present are:
- Eustrongylides, representing the genus of Dioctoform nematodes. These whitish-red or completely red thin worms in fish consistently parasitize the stomachs of birds, getting there with the fish they eat. The latter acts as an intermediate carrier of this type of parasite. Such worms are very thin and long, reaching a length of 50 mm and are localized in the abdominal zone of the fish, muscles, stomach, intestines, testes and liver. If there are too many larvae, they cause hyperemia and hardening of the stomach tissues of catfish, perches, and also lead to the destruction of the kidneys of sturgeon fish. Red thin worms in fish lose their harmful properties with sufficiently intense heat treatment. The fish meat becomes edible and can be safely used as food. However, it is still better to remove pieces from the fish in which eustrongylides is located.
- There are also other long red worms in fish that are dangerous to humans. They are similar to filomentra, but longer and brighter in color. These individuals reach a record length from fifteen centimeters to a whole meter. They are found in freshwater bodies of water and pose a great danger to humans. This type of helminth has been studied very little, and there are no clear recommendations on how to effectively treat the diseases caused by it in humans. To avoid a disappointing outcome from such a meal, it is better to refrain from eating fish with such inclusions.
Philometra in fish: what kind of parasite is it?
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Philometra are long, thin, red worms in the body of a fish. Most often they can be found in the fins and head area. These parasites cause the disease phylometroidosis, which is not dangerous to humans. It infects such river inhabitants as pike, carp, bream, carp, crucian carp and perch.
If there are red worms in perch fish lurking in the muscle tissue, know that they can cause weakening of the muscles and the human body. And although phylometra is not dangerous for humans, fish suffering from phylometroidosis becomes loose and lethargic, and its meat becomes tasteless.
Red worms can often be found in dried fish. Dried perch is also susceptible to dominance by these parasites, and even if the salting and drying technology is carried out correctly, these helminths, even after their death, do not leave captured areas of the fish. In principle, as already mentioned, phylometers are safe for people, and salt makes its contribution to the fight against this parasite, but it is better not to take risks by eating affected parts of the fish.
What parasites are still found in perch?
There is an opinion that helminths can only be found in freshwater fish. But this is not true, because marine species can also be infected with worms. For example, there are parasites in sea bass, photos of which can be seen below.
Certain types of parasites that live on fish may not be dangerous to humans. Most often it is a large and long helminth called ligula.
Also found in perch:
- schistocephamos;
- Cystidicola pharyonis;
- Trienophorus nodulosus;
- phylometra.
Dangerous pathogenic microorganisms include Iffilobothrium dendriticum and Diphyllobotrimum latum.
Opisthorchiasis is often found in cyprinids. Red and sea fish cannot be infected with opisthorchiasis. But flukes often infect roach, crucian carp, bream, carp, and so on.
Parasites of sea bass - Sfirion lumpi. These are crustaceans with a long and narrow neck, a wide head and a flat body. Their length is from 4 to 7 cm. Young individuals are white, and old ones are brown.
Reference: Sphyrion is found in beaked, golden and small sea bass.
Only the head and neck of the crustacean penetrate the muscle tissue of the fish. Ulcers form in the implantation zone. If they are large, then they contain sticky exudate.
Parasites on sea bass, the photo of which is shown below, are isolated from the host by forming a connective tissue capsule that may protrude slightly above the ulcer.
There may be more than one parasite in sea bass. Thus, the number of crustaceans that infect fish can reach 12 pieces. Moreover, even after the death of the parasitic microorganism, the capsule remains in the body of the perch.
Advice from an experienced ichthyologist
The most common “guests” are tubular small red worms in fish, up to 5 cm in length. They can be found in perch, goby and walleye. It is quite possible to eat fish infected with them, after first clearing its meat of parasites.
According to information from candidate of biological sciences Roman Novitsky, an experienced ichthyologist, such fish must be thoroughly cleaned and properly prepared. If you fry it, then you should do this for at least 10 minutes so that the helminths come out, and if you decide to salt it, then keep the fish carcass in a salt solution for at least two days. According to him, when frozen, these parasites do not die and after thawing they become completely viable.
Novitsky also advises paying attention to herring, which at the moment, according to statistics, is 60% infected with helminths. The cleanest fish, according to the ichthyologist, are catfish, mackerel and tuna, which live in the open sea. But even here the presence of parasites could not be avoided. It’s just that there aren’t so many of them compared to other types of fish, and they don’t catch the eye. For this reason, carefully process all fish that are intended for your food, just in case.
Are there parasites in red fish?
Red fish is the most delicious and popular. There is an opinion that it is impossible to get infected with helminths from sturgeon breeds due to their noble origin. Today this opinion is largely refuted. And when eating the meat of this class of fish, there is a real chance of picking up one or another parasite. Try not to eat this fish raw or cooked in violation of the recipe and processing time - you can cause your body quite serious problems with poisoning.
The main suppliers of helminths include pink salmon, salmon and trout. What worms are present in red fish (photos of some are presented below for clarity), and how dangerous are they for humans?
Red fish dishes are not uncommon in modern cuisine. They are usually timed to coincide with major holidays or serious social events. Imagine the amazement of the eater if he notices that there are transparent worms in the red fish. And yet, this kind of thing happens. Therefore, red fish is by no means a guarantee of the absence of worms.
Many gourmets love dishes made from raw or half-raw pink salmon, chum salmon, and salmon, and don’t even think that along with the amazing-tasting delicacy, one of the parasites can enter the body. Thus, in Japanese cuisine, it is customary to prepare fish dishes with a minimum processing time and amount of salt, so as not to spoil the true aroma and taste of the product, as well as to preserve minerals and vitamins.
If worms or their eggs enter the human digestive tract, he will experience a rash on the skin, severe digestive upset, nausea, vomiting and many other signs of fish poisoning.
Transparent worms in red fish: worms, worms, parasites dangerous to humans
Sushi, rolls, salads and delicacy minced meat prepared with red fish are gaining more and more popularity in the world.
Gourmets are confident that minimal heat and salt processing of fillets preserves the unusually fresh, incomparable taste of marine life. And the beneficial substances are not destroyed. However, such a delicacy can “give” people who eat amazing dishes other surprises in the form of quite serious diseases. So are there parasites in red fish, how to detect them and what ways to prevent infection?
What parasites are found in red fish?
Diseases caused by parasitic organisms are called helminthiases. The main culprits of illnesses are flatworms and roundworms that enter the human body along with food.
Red fish, considered one of the best delicacies, is, alas, no exception. Eating this seafood raw or improperly processed can cause quite serious poisoning and conditions.
The main “suppliers” of helminths are trout, salmon, pink salmon and chum salmon . What parasites are found in red fish that are dangerous to humans?
Wide tapeworm
This parasite belongs to the genus of tapeworms and causes a disease called diphyllobothriasis. In red fish, these creatures are located in small capsules that resemble a grain of rice in appearance, with thin translucent walls.
When the shell is destroyed, “young” parasites of white or milky color enter the liver, muscles, milk and caviar of red fish , beginning their development cycle. They reach up to 5.5 cm in length and do not exceed 0.3 cm in width.
Attention! Developing in the human body, this parasite can grow up to several meters! The longest wide tape recorded by scientists was 12 meters.
Wide tapeworm in red fish
Symptoms of diphyllobothriasis:
- intense nausea;
- frequent vomiting;
- discomfort and even pain attacks in the abdominal area;
- stool disorder;
- marked deterioration or improvement of appetite.
With prolonged invasion, anemic conditions develop, which are characterized by weakness, rapid physical fatigue, decreased mental performance and other symptoms inherent in anemia. In some cases, an itchy rash may appear on the skin.
Attention! The lifespan of the broad tapeworm in the human body can reach up to 15 years.
Trematode (salmon fluke)
This parasite lives in the salmon and grayling fish families and provokes a disease called nanophyetosis.
But the source of infection can be not only salmon, but also a person in whose body helminths have settled.
This helminth in red fish looks like a microscopic pear-shaped worm with a transparent yellow or brown color. The dimensions of the parasite are microscopic: from 0.5 to 1 mm in length and from 0.2 to 1 mm in width.
Signs of trematode damage:
- stool disorders;
- nausea and vomiting attacks;
- worsening or unusual improvement in appetite;
- enlarged liver, noticeable on palpation;
- pain in the pancreas area.
With massive invasion or a long course of the disease, the addition of psychoneurological disorders is quite likely, the most severe of which is epilepsy.
Important! The sooner a person with suspected nanophyetosis turns to doctors, the more successful and quickly the treatment will work, and the less damage the parasite will cause to the body.
Anisakids
These worms from the genus of nematodes (roundworms) live not only in red fish, but also cod, herring and some other representatives of the deep sea. They cause the disease of the same name, which in scientific language is called anisakidosis. Unlike other harmful “brothers,” these creatures enter the human body in the form of light brown or yellowish larvae.
Reference. Worms in red fish can be up to 1000 pieces in one individual!
Spindle-shaped worms with rounded tails and three lips at the head end of the body quickly penetrate the internal organs and muscle muscles of the fish, where they continue to develop and reproduce.
Fish infected with anisakids
This parasite enters humans through consumption of seafood that has not undergone sufficiently intensive heat treatment, salting or smoking. People who love dishes made from raw and lightly salted fish, and connoisseurs of sushi and rolls are at risk.
Symptoms of anisakidosis:
- pain in the epigastrium and iliac region;
- nausea and vomiting;
- skin rashes like urticaria;
- flatulence;
- stool disorders.
Important! The disease is often accompanied by an increase in body temperature of up to 38 degrees, and if the stomach is affected by anisacids, which provokes the reflux of bile into the esophagus, a sore throat, cough and other symptoms similar to respiratory infections may be observed.
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If left untreated, this parasitic disease, caused by worms in red fish, can lead the patient to severe intestinal obstruction with subsequent perforation, intestinal perforation and peritonitis , which, in turn, will lead to death without surgical help.
The causative agent of the disease, called metagonimiasis, is helminths from the genus trematodes with a length of up to 2.5 mm and a width of up to 0.7 mm, the body of which is covered with small outgrowths resembling thorns.
Once inside the body, these parasites settle in the small intestine, where they begin to actively grow and multiply.
Manifestations of metagonimiasis:
- prolonged diarrhea; severe nausea;
- fever;
- skin rashes;
- eosinophilia.
If the disease is not treated, it will provoke enteritis, which will subsequently lead to more serious complications.
How to detect parasites in red fish
Unfortunately, most helminths are very difficult to notice by the naked human eye. But there are still some signs that make it undesirable to eat red fish :
- Small, swelling-like whitish formations on the flesh that can be noticed when cutting.
- Thin threads, worms found in offal.
- Flabby, not very fresh-looking meat.
- Perishable seafood.
- The transparent worms in the red fish are most likely already dead, but it’s not worth the risk.
Quite harmless parasites can also live in fish, which pose a danger to animals, but not to humans. For example, phylometers are reddish creatures up to 5 cm long. However, red worms are not found in marine fish, preferring freshwater inhabitants.
Prevention measures
The main condition that can prevent the entry of helminths from fish into the human body is proper cooking . For meat to be safe, it must:
- fry;
- boil;
- smoke;
- salt well;
- freeze for more than 24 hours at -20 degrees.
And lovers of dishes that contain fresh red fish can be advised to choose only trusted establishments that comply with all culinary standards, and regularly undergo medical examinations by specialists.
Source: https://101parazit.com/gelminty/ploskie-chervi/opistorhoz/parazity-v-krasnoj-rybe.html
Flat ribbon-shaped parasites: how dangerous are they for humans?
Infection occurs through eating food with viable helminths. They are classified into two subclasses - round tubular worms and flat tape worms. Any red fish caught industrially in a free sea or river body of water contains parasitic worms.
One of them, the wide tapeworm, is located in the larva, which is a thin translucent shell. They look like a grain of rice, and after the destruction of the capsule, transparent worms appear in the red fish. These parasites are found in fish eggs and inhabit their body and gastrointestinal tract. At the same time, they affect the liver and muscles of the fish, as well as its milt.
The white worms found in red fish - young tapeworms - are about 55 mm long and 2 mm wide. In appearance they resemble a white or milky transparent tape, which, when entering the human body, can grow to gigantic sizes - up to twelve meters. Tapeworms live 15 years or longer and throughout their lives they infect the host (human) body, destroying its internal organs.
A person infected with this parasite experiences severe weakness, headaches, loose stools, poor appetite, nausea, heartburn, belching and vomiting. Skin itching and rash may occur. The larvae of these helminths can survive even with very long processing of the carcass. Even freezing will not help, because the larvae are viable at a temperature of 4 degrees. They can only be destroyed with salt if the salting continues for several (3-5) days.
Diphyllobothriasis
The disease develops when infected with tapeworm (tapeworm), a parasite dangerous to humans and other mammals. This is a large tapeworm up to 15 m long and up to 1.5 cm wide. Its life cycle takes place with a change of two intermediate hosts:
- first-stage larvae emerge from parasite eggs in water;
- they are swallowed by small aquatic mollusks - crustaceans, cyclops;
- larvae of the second stage are formed in their body;
- infected shellfish are consumed by fish;
- larvae of the third stage are formed in them;
- they are encapsulated - covered with shells.
On a note!
Capsules with tapeworm larvae pose an invasive threat. They look like grains of rice, are white or milky in color, round in shape, up to 0.6 cm long. They are easy to notice in the muscle mass when cutting raw red fish. One carcass can contain up to 250 parasite larvae. Most often such parasites are found in pink salmon and chum salmon.
Symptoms of infection
Infection of humans and animals with diphyllobothriasis occurs only when eating fish infected with the larvae of the parasite. There may be worms in red caviar, milk, liver, and muscles. The main symptoms of fish worm infection:
- nausea, vomiting, diarrhea, constipation;
- allergic skin rash, itching, burning;
- decreased appetite, weight loss;
- headaches, weakness, fatigue;
- severe anemia, dizziness.
On a note!
In the human intestine, the capsules rupture, the larva comes out and turns into an adult tapeworm within 2-3 months. The life expectancy of the helminth is up to 12-15 years. Most often, one adult tapeworm is formed; new parasites are not formed. A person becomes a constant source of worm eggs, which pollute the environment with feces.
Parasites in red fish
Prevention of diphyllobothriasis
The main preventive measure against tapeworm infection is to beware of eating red fish that has not undergone the disinfection process. Under industrial conditions, deworming of parasites in pink salmon and other varieties is carried out using the following methods:
- long-term freezing at a temperature of -12⁰С for 14-15 days;
- keeping fish in salt water for 21-22 days;
- boiling at a temperature of 100⁰С for 20-30 minutes.
Important!
At home, fresh or store-bought red fish carcasses must be thoroughly boiled, fried, and re-frozen in the freezer. In this way, it is possible to kill the larvae and destroy their encapsulated cysts.
Round tubular parasites in red fish - are they dangerous to humans?
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Round tubeworms also bring a bad disease to people - anisakiasis. Parasites such as anisakids are present in each of the marine fish, but chum salmon is most preferred, followed by salmon and pink salmon. These pathogens affect almost all fish organs - the body, muscles, liver, milk, spleen, eggs and gastrointestinal tract. These parasites have a spiral shape and reach a length of 5 cm. The color of the worm is whitish, brown or cream. Their introduction into the mucous membranes of the human stomach and intestines is a direct path to intestinal ulcers. The implantation process is accompanied by swelling and ulcers. Often the presence of this helminth causes intestinal obstruction and also disrupts the functioning of the gallbladder, liver duct and pancreas.
Definition of opisthorchiasis
Opisthorchiasis is a disease caused by a specific parasite. An alternative name for the disease is cat fluke.
Today, this disease has become widespread among animals and people who eat fish.
There are parasite eggs in human feces, and through shellfish that ingest them, these elements have a certain cycle. Then the flukes enter the muscle tissue of the fish and, together with a poorly processed gastronomy product, end up in the human body. The parasitic element settles in the area of the gallbladder and ducts, liver, and near the pancreas . In soil conditions, the helminth lives for 10 days or more, in an aquatic environment the life expectancy is up to a year. This pest can stay in the host’s body for years.
The incubation time is from 21 days , the onset of human disease is accompanied by acute symptoms. With untimely treatment or its absence, the acute form, as usual, passes into the chronic stage.
What to do to protect a person from the consequences of fish helminths?
Is it possible to eat fish infected with parasites? Sanitary standards classify such food as conditionally suitable. To make it completely safe, it is necessary to subject the fish to a special regime of heat treatment or salting. Do not eat raw or semi-raw fish - even a very refined taste will not compensate you for possible serious problems associated with infection with parasites. Here are some tips on how to choose and buy uninfected fish:
- Pink salmon and other sturgeon should be purchased in specialized stores, where they monitor its purity and subject it to the necessary industrial processing.
- Give preference to fish grown artificially and fed with artificial food.
- Freshly caught sea fish should be frozen immediately and defrosted only just before preparing the dish.
- If it is not possible to freeze, immediately gut and start cooking.
To protect fish, it can not only be boiled or fried, but also smoked, salted, marinated, but this must be done strictly in accordance with certain cooking technologies. For example, when frying or boiling a carcass, the cooking time should be at least 15-20 minutes. If the fish is quite large, then its meat must be separated from the ridge. When preparing a fish pie, bake the product in the oven for at least half an hour, and preferably longer.
Special preventive instructions
Sanitary standards assign conditionally suitable status to fish infected with worms. It cannot be eaten raw, unprocessed, but only after appropriate culinary disinfection:
- freezing for 2 days at -20°C;
- deep freezing at -27°C for 12-15 hours;
- keeping at –4°C for at least 25-30 days;
- exposure in salt water for at least 15 days;
- cook in boiling water for 15-20 minutes;
- fry at 180-200°C in a closed pot or oven;
- smoking by hot salting for 7-9 days.
Parasites in commercially produced frozen fish are completely killed. When buying pink salmon, chum salmon or salmon from trusted retail outlets, you can be confident that the product is safe. Freshly caught sea fish (char, trout and other red fish) must be immediately frozen or heat-treated after thoroughly gutting the insides.
Smoking and freezing fish
For high-quality smoking, fish up to two kilograms in weight are neutralized as follows:
For this procedure, salt is taken in such quantity that its weight is at least 20 percent of the weight of the fish. That is, if you have a kilogram carcass, you will need 200 grams of it.
When red fish is frozen, all parasites die within two days if the fish is kept at a temperature of -20 °C. If you freeze it at a temperature of -27 °C, the period can be reduced to twelve hours. If you use the freezer compartment of a regular refrigerator with a temperature of -4 ° C, the fish must be kept in such conditions for at least a month.
