Marine parasites

The question for many fish lovers, my patients, one of the main!Fans of fish can be distinguished from other patients in the same symptom: starts to bargain about what kind of fish you can still have salt. At the reception always say that any fish to eat only heat-treated. Hear in response: opisthorchiasis and difillobotrioz in marine fish no, salt kills worms, as well as alcohol, seafood (squid, mussels and octopus) there are no worms.

Anisacidosis person

marine parasites

Etiology

Pathogens anisacidosis human – larval stage of development of helminths of the genera: Anisakis, Contracaecum, Pseudoterranova, Hysterothylacium, which belong to the order Ascaridida Skrjabin et Schikhobalova, 1940, of the family Anisakidae Skrjabin et Korokhin, 1945. The definitive hosts of these helminthes are many marine mammals, predatory fish and piscivorous birds, in the gastrointestinal tract which are parasitic males and females. Hence the name of the disease – anisacidosis.

The average length of females anisacidosis 60-65 mm in males 50-55 mm. Body fusiform, narrowed to both ends (more narrowed to the head end). At the head end anisacidosis has three lips. Fertilized eggs fall into the water, where they comes out the larva, which swallow the first intermediate hosts are crustaceans from krill, often belonging to the family Euphausiidae.

Additional hosts are a marine fish, molluscs, larger crustaceans that feed on small crustaceans. Larvae in body of intermediate hosts are found in the body cavity, on the surface or inside of various internal organs and in the muscles of fish. They are inside the translucent capsules – cysts, or without them. The size of the cyst, on average, 3-7 x 1-2 mm.

Infection of final hosts occurs when Anisacidosis them eating infected intermediate hosts: fish, crustaceans and molluscs. If larger, the intermediate hosts eat the smaller ones, which are infected with larvae, the larvae accumulate in the body larger, predatory fish.

How is the infection

Man becomes infected by eating the sea fish and seafood, which contain viable larvae. Disinfection of seafood from larvae probably freezing and heating. In normal saline and other solutions, which are used to prepare fish larvae can remain viable for many days and even months. Freezing fish to -18C leads to the death of all larvae within 14 days; at -20 ° C they die within 4-5 days; at 30 ° C are killed within 10 min. In squid larvae die at -40C in 40 min.; at -32C for 1.5 hours; -20C for the day.

In the United States and the Netherlands sanitary rules regulated by freezing fish that will not be subject to subsequent thermal treatment, at 20C for 5 days.

Larvae can tolerate a temperature of up to +45C. At a temperature of +60C and above they die within 10 min, Thus, Smoking fresh fish in a temperature range of +45-60C does not guarantee disinfection from larvae. The immune system is not stable.

Anisacidosis person was first diagnosed in Holland in 1955, In the last two decades, this invasion becomes one of the important problems in medical Parasitology. To date, the cases registered in many countries of Europe, North and South America and Southeast Asia.

The incidence of people has a strong tendency to increase in connection with the increase in the consumption of marine fish, shrimp, squid, octopus and other sea foods, as well as in connection with the improvement of the diagnosis of this disease. In 1987, in Germany there was a serious precedent that is associated with the detection of live larvae in finished products from Atlantic herring.

the causes of diseases

Many marine fish infected with larvae. For example, from 25 to 100% of the populations of halibut, flounder, salmon, cod, herring and other fishes of the Okhotsk sea affected by them. Do not lower the level of contamination and fish from the Pacific and Atlantic oceans. Prevalence of squid in the Pacific ocean reaches 28%. After the catch of fish of the larvae, which was in the digestive system, quickly and actively migrates from there to other organs (muscle, eggs, milk). So the gutting and cleaning of fish and shellfish in the shortest possible time after their catch dramatically reduces the likelihood of contamination of edible parts.

Pathogenesis

When released into the gastrointestinal tract of humans, the larvae actively head end in the mucosa and submucosa throughout the process from the pharynx to the colon. Most often they are found in the walls of the stomach and small intestine. At the site of penetration of larvae is inflammation, which is accompanied by eosinophilic infiltration, edema. Further, the formation of eosinophilic granulomas, necrosis and perforation of the intestinal wall. Inflammatory processes and neuro-reflex reactions can lead to bowel obstruction. Sometimes the larvae migrate to the gallbladder, ducts of liver and pancreas, causing these organs in the inflammatory response and formation of granulomas. In humans, the parasites before puberty do not develop, and the lifetime ranges from several weeks to 2-3 months. However, the symptoms of the disease caused by toxic and allergic effects of larvae of helminths on the human body, including as a result of formation of granulomas can be observed for several months or even years.

Symptoms and treatment

The incubation period ranges from several hours to 7-14 days. In many respects the clinical picture, symptoms Anisacidosis due to the localization of the parasites. When finding larvae in the intestinal lumen, and symptoms can be very scarce. Gastric localization (the most common form of the disease) patients worried about severe pain in the epigastrium, nausea, vomiting, sometimes with blood. It is noted subfebrile or febrile fever, development of allergic reactions immediate type (urticaria, angioedema). In the case of retrograde migration of the larvae from the stomach into the esophagus you are experiencing symptoms such as pain and irritation in the throat, cough. With intestinal infection, patients complain of pain in the umbilical region and right iliac region, with rumbling in the abdomen, flatulence. You may experience symptom of acute abdomen, characteristic of appendicitis or intestinal obstruction. The disease can be acute, subacute or chronic.

Complications

To serious complications of intestinal parasite include perforation of the intestinal wall and penetration of intestinal contents into the abdominal cavity with the development of peritonitis.

Diagnosis and differential diagnosis

Larvae can be detected by contrast radiography and endoscopy or the study infected in the surgical operations section of the stomach and intestines. When fibrogastroduodenoscopy in the field of introduction of worms, revealed mucosal edema with multiple petechial erosions. In the study of blood revealed a moderate leukocytosis and eosinophilia. Serological diagnostic methods have not been developed. If coproscopic larvae or eggs of larvae does not occur. Identification of the parasite to genus and species possible in the study of larvae, removed by endoscopy or surgery.

treatment

Anisacidosis should be differentiated from gastric ulcer and 12 duodenal ulcer, gastritis, pancreatitis, cholecystitis and tumors. Intestinal form is necessary to exclude appendicitis, diverticulitis, tumors, colitis and enterocolitis.

Treatment

Treatment of parasites rather poorly developed. There are small developments on the effectiveness of special preparation. But there is no clear schemes. Again, the lack of a precise treatment should alert fans of fish and to limit its application only after heat treatment.

16.01.2019