Worms in fish: what is the real risk?
Jun 20, 2018
Rich in minerals and rare trace elements, fish are a frequent product in the diet of almost everyone.And few people think about the fact that fish can be dangerous to human health, but it is associated with a high risk of infection with worms when consuming the inhabitants of rivers and seas / oceans.Diseases that can be transmitted together with worms while eating fish are so many that scientists have identified them in a separate group and named it "fish helminthiases" .The danger is that fish infected with worms are absolutely indistinguishable from healthy ones, and yet studies confirm that all inhabitants of freshwater reservoirs, as well as of seas and oceans, can be carriers of eggs and worm larvae.
It is worth knowing that even the purchase of fish and seafood in a specialized store does not guarantee the purity of the product.In accordance with the regulations, each fish body must be checked for invasive infection.According to sanitary norms it is considered that if the number of individuals of non-viable worms has exceeded 5, then the product should be disposed of.A smaller indicator allows the product to be sold, but with the condition that it must be subjected to deep heat treatment before consumption.
Sexually mature specimens of worms and their larvae can be found in any part of the fish, but most often helminths are found in the liver, gills, muscle tissue, belly or head of fish.There are also kinds of parasites that are located in milk and caviar bags!Contents: Worms in herring Anizokidoz Opisthorchiasis Diphyllobothriasis ligulosis Dioktofimoz Chernilnopyatnistaya disease Filometroidozy Diplostomoz How to fish infested with worms infection prevention Rules fish helminth
Worms in herring
traditional Slavic cuisine does not imply the use of raw fish, but do notTo exclude herring from sight.Its high taste and relatively low cost made the most popular dish of both festive and everyday menus.Yes, at salting fish helminths perish and do not pose a danger to humans.But this happens only if the technology of fish salting has been strictly observed.
For example, not everyone knows that right after the catch and before pickling, the herring must be frozen - this will exclude all worms from it.But unscrupulous producers who want to earn more and earn more often neglect this rule.Proceeding from this, it can be stated with certainty that it is quite possible to get infected with worms when eating herring.
The most common type of helminthiasis that affects a person is anisokidosis, which develops due to parasitization in the human intestine of anisochid larvae.Infection with these larvae occurs in the case of the use of salted fish dishes, this applies to salted herring.
Symptoms of anisocidosis:
- abrupt, unexpected abdominal pain;
- nausea and vomiting;
- causeless disorder of the stool.
Often considered the disease with its symptoms simulates an attack of acute appendicitis - it is natural that the patient in most cases is on the operating table.
Note: data of the worm larvae, entering the intestine of a person, literally bite into its walls( anisocides have incisors).This provokes intestinal bleeding, which develops rapidly and can lead to the death of the patient.
The larvae of anisocides excellently tolerate temperatures of up to 65 degrees Celsius, so eating smoked and dried fish is also a danger.There is also some peculiarity in the worm in question: once the fish is caught, the larvae migrate from the intestine to the muscles.Therefore, according to the sanitary standards, one can prevent infection with anisoids only in one way - gutted fish immediately after the catch.
It is caused by a cat's fluke - this causative agent parasitizes foxes, ferrets, arctic foxes and other carnivores in the body.Most often, the carriers of the cat's fluke are dogs and felids, and intermediate "masters" are representatives of the carp family.
A person can become infected with opisthorchiasis by eating raw fish, or after incomplete heat treatment.The disease is characterized by pathological lesions of the liver, pancreas, gallbladder and its ducts.First, the opisthorchis larva enters the duodenum, then moves to the liver ducts, and after 12 days of "settling in" the egg laying begins in the human body.Eggs develop within 4 months, at the end of this period, sexually mature worms appear. It is from the moment of their appearance that the infected person can notice the appearance of the following symptoms:
- bitter taste in the mouth;
- a constant feeling of nausea;
- pain syndrome in the right hypochondrium;
- a constant sense of heaviness in the anatomical location of the liver;
- non-perception of fatty foods - it just does not digest;
- in the evening hours there is a regular fever;
- there is a disorder of the stool( there may be diarrhea and constipation).
In the absence of treatment, the disease under consideration passes into a chronic form of flow characterized by irreversible destructive processes in the liver.The result is a rapid development of liver cirrhosis and death.
This disease occurs when a wide-spreading worm has settled in the human body.In some cases, this type of parasites grows to a length of up to 25 meters!
Eating poorly processed fish raw materials as well as raw water can lead to infection.2-3 months after the larvae enter the human body in its small intestine, an adult specimen of a wide ribbon already lives.The main manifestations of diphyllobothriasis are regular abdominal pains, nausea, frequent dizziness, periodic headaches, decreased appetite, a sharp weight loss.Against the background of the disease under consideration, the spleen and liver are enlarged in size, and iron deficiency anemia is often diagnosed in patients.
The causative agent of this disease is a tapeworm, whose adult individuals live in the organism of fish-eating birds.Man in this case is an intermediate "master" and it becomes so when eating fish from the family of carps.
Glist can reach a length of 120 centimeters, is placed in the intestine and exerts constant pressure on the internal organs.Such an effect provokes a disruption of their functionality, and the decay products from the vital activity of the parasite cause an intoxication of the body - a person develops diarrhea, nausea, dizziness and fever.
Note: if the fish of the carp family is affected by this helminth, then it is easy to determine - the swollen abdomen does not collapse with pressure, as this is where the worm is located.The fish itself will look drained, as it has impaired metabolism.
This is one of the most dangerous helminthiases that a person can get by eating infected fish.The parasite most often lives in the bladder, kidneys and ureters of a person.Adult specimens of worms( and first enter the renal pelvis larvae) disrupt the entire urinary system, which leads to renal colic and renal failure.
Remove parasites from the body only surgically.The operation is appointed by the doctor after the examination of the patient, who will be diagnosed with pyelonephritis, renal colic and inflammation of the urinary tract of unknown origin. The manifestation of dioktofimoz will be:
- blood in the urine;
- intense back pain;
- with repeated vomiting;
- general weakness.
All anglers who already have experience in this matter, necessarily pay attention to the appearance of the fish.They do not use fish on which there are black dots and it is not accidental.Such black "marks" located on the trunk, fins and mucous eyes of fish, indicate that it is infected with a parasite, which is the cause of post-dystoplasmosis.
The worms themselves have nothing to do with these black points on the fish, these "traces" are left by the larvae that enter the deep layers of the skin of the fish and form a protective capsule around them.
Note: undeveloped helminth does no harm to humans.Even such a damaged fish can be eaten, but only after sufficient heat treatment.By the way, deep roasting and prolonged quenching will relieve the fish not only from a parasite that provokes the development of post-dystoplasmosis but other representatives of worms.
Sometimes, in the process of cleaning fish from scales, you can see under it small pinkish worms, which are always folded into a ring - these are phyllometroids, roundworms.The females of this parasite "live" in the scales, and the males are in the air bladder( in its walls).Some representatives of these helminths can reach a length of 12 centimeters.
For a person, these parasites do not pose any danger, but the fish will have damaged internal organs.
This kind of fish helminthiasis is also absolutely safe for humans, as the conditions inside the body are absolutely unsuitable for growth / development / reproduction of these worms.
How to identify fish infected with worms
Of course, I would like to believe that on the counters of outlets comes an exceptionally healthy, non-infected worm fish.But it's more like a fantasy, so you need to know how you can recognize the infected fish. Remember how the product absolutely unfit for consumption can look like:
- is absent rigor, so its muscles are soft, it does not disappear when pressing;
- pupils of fish are turbid and have parched mucous membranes;
- scales easily separated, under it appears sticky skin;
- the abdomen of the fish is saggy and swollen;
- gills have a marshy hue;
- internal organs of fish produce an unpleasant odor;
- The anal opening of the fish strongly protrudes, a turbid mucus follows from it.
Rules for the prevention of infection with fish helminthiases
Naturally, do not give up eating fish, even if there is a high risk of infection with worms. You only need to know some safety rules and strictly adhere to them:
- fish and minced fish are prohibited to be tasted during cooking;
- if you need to cook fish, then it should boil for at least half an hour;
- large fish before frying must necessarily cut into pieces, or on the seams;
- for salting the fish should be soaked for 5 days - 2 weeks, it all depends on the type of salting.
Fish helminths can present a real danger to health and in some cases even to human life.Know about this danger is necessary, but not to use this useful product is not worth it.When observing the standards for cooking fish, it is possible to avoid infection by the worms / eggs of the worms.
Tsygankova Yana Aleksandrovna, medical reviewer, therapeutist of the highest qualification category