Parasites in herring
Helminthiasis is an infection caused by the ingestion of eggs, larvae and sexually mature representatives of various parasites into a living organism. Very often helminths parasitize in fish, since this environment is extremely suitable for their life and reproduction. High humidity combined with an optimal temperature are factors that are very favorable for the development of parasites. Both sea and river fish become victims of helminths.
You can protect your body from infection with parasites using heat treatment of fish. However, not all fish dishes require long cooking at high temperatures. A traditional product on almost every table is light-salted herring. However, it is this fish snack that often carries the threat of infection with helminthiasis.
Presale sanitary control allows the presence of parasites in the herring, but no more than 5 dead individuals per carcass. According to sanitary standards, fish that are not subject to heat treatment during use must be frozen.
This is interesting: some of the parasites that live in the herring are harmless to humans. These types of helminths lose their viability, getting into the gastric juice.
Content:
- What parasites can harm human health?
- How do you know if the herring contains parasites?
- What do parasites look like in a herring?
- How to protect yourself from infection?
- Is it okay to eat herring infected with parasites?
- What to do in case of infection?
What parasites can harm human health?
Some parasites in herring are able to survive in the aggressive environment of the human stomach and intestines. They perfectly adapt to the conditions of the gastrointestinal tract, multiply there and cause irreparable harm to the health of their new "owner".
The most dangerous types of helminthiasis transmitted through the use of lightly salted herring:
- Opisthorchiasis;
- Diphyllobothriasis;
- Anisakidosis.
Opisthorchiasis. This type of helminthiasis is caused by the cat fluke. It is carried by mammals eating live fish. If poorly processed fish enters human food, then he becomes a target of opisthorchiasis. Fish is an intermediate host of the feline fluke, a carrier of the disease. The consequences of opisthorchiasis are damage to the digestive system, liver, gallbladder and bile ducts.
Diphyllobothriasis. This type of parasitic invasion is caused by a wide tapeworm, reaching a length of 25 m. Diphyllobothriasis provokes the following symptoms: anemia, abdominal pain, nausea and weakness, sudden weight loss, loss of appetite.
Anisakidosis. The disease is caused by anisakids - roundworms that look like roundworms. Parasites actively feed in the human stomach and intestines, disrupting the integrity of the mucous membrane. This is accompanied by symptoms similar to those of appendicitis: nausea and vomiting, diarrhea, fever. Massive Anisakida infestation can be fatal.
How do you know if the herring contains parasites?
In order not to purchase herring with parasites, you should take precautions. Carefulness when choosing fresh or lightly salted fish will help avoid helminth infestation. But sometimes parasites are found already during cutting and cooking.
Signs of the presence of parasites in herring:
- Dent after pressing with a finger, remaining on the carcass for a long time;
- Cloudy eyes with a gray tint;
- Unnaturally distended abdomen;
- Foul odor and dark gills;
- When cleaning fish, it is noticeable that the insides have a repulsive sulfuric, putrid smell;
- A broth made from poor quality fish does not have a characteristic oily film; instead, white flakes of foam from coagulated protein appear on the surface.
In large retail outlets or in specialized fish stores, all products undergo sanitary control. These precautions are your best insurance against buying parasitic fish.
What do parasites look like in a herring?
You can see parasites in herring with the naked eye. Their main habitat is near milk or caviar.
The appearance of anisakida, one of the parasites in the herring, resembles roundworm. These are round, fusiform worms 5-6 cm long. There are 3 lips at one of the rounded ends of the anisakida. The larvae of this parasite are extremely dangerous for humans.
In the feline fluke, which provokes the development of opisthorchiasis, the size of the flattened body does not exceed 3 cm, and its thickness is 1.5 cm. They enter the human body in the form of larvae, indistinguishable from the ordinary eye.
Heat treatment of the fish would certainly destroy these parasites in the herring, since cooking at a high temperature (100 ° C) completely deprives the helminths of their viability. However, salted or smoked herring is not exposed to high temperatures, leaving the risk of infection.
Saline does not always kill larvae and sexually mature individuals. In some cases, this measure even makes the parasites more viable. The smoking temperature is so low that it cannot guarantee safety. On the contrary, the increased temperature during smoking is an additional factor for the favorable development of parasites in the herring.
How to protect yourself from infection?
In order not to get parasites in the herring, during the purchase, you should follow simple rules:
- Avoid buying gutted herring, since it is much easier to detect parasites when cutting fish than in preserves and semi-finished products;
- You need to buy fish only in specialized outlets, departments of large supermarkets;
- Fresh fish is stored in the freezer of the refrigerator at a temperature not exceeding -20 ° C;
- 10 minutes of holding the fish at a temperature of -30 ° C will completely protect it from parasites;
- Fish should be fried for at least 20 minutes, cutting the carcass along the ridge;
- Cooking fish is carried out at least 20 minutes from the moment the water boils;
- Cooking fish pies in the oven cannot take less than half an hour.
Is it okay to eat herring infected with parasites?
Of the 300 species of parasites found in fish, only a few species are dangerous to humans. This danger persists only if fish dishes are not properly stored and prepared. Freezing freshly caught herring at very low temperatures will destroy the parasites in the intestines of the fish, preventing them from entering the muscle tissue. Having removed the eggs, milk and intestines of the herring, it can be eaten without hindrance.
Having found parasites in the herring intestines, you need to make sure that they are not viable. The dead individuals are not dangerous, they only harm the aesthetic feelings of consumers.
What to do in case of infection?
Patients infected with parasites are treated by a parasitologist and infectious disease specialist. The incubation period for anisacidosis is 10-14 days. To clarify the diagnosis, differential diagnosis of diseases with similar symptoms is carried out. In a laboratory study, the larvae of the parasite are found in the feces and vomit.
The patient undergoes FGDS - a study of the digestive system using a gastroscope. As a result of this study, erosion of the mucous membrane and helminth larvae can be found in the stomach and in the duodenum. When collecting an anamnesis, the doctor specifies whether the patient has eaten fish that has not been thermally processed.
Treatment of parasites can be both surgical and medication. Anthelmintic drugs - Mebendazole, Albendazole. With complex forms of helminthiasis, the patient is registered at the dispensary for a year, regularly undergoes fibrogastroduodenoscopy (FGDS).
Author of the article: Danilova Tatyana Vyacheslavovna | Infectionist
Education: in 2008 received a diploma in General Medicine (General Medicine) at the Pirogov Russian Research Medical University. Immediately passed an internship and received a diploma of a therapist
