The question for many fish lovers, patients, one of the most important!Fans of fish can be distinguished from other patients with the same symptom: starts to bargain about what kind of fish you can still salt. The front desk always said that the fish eat only heat-treated. Hear in response: opisthorchiasis and difillobotrioz marine fish is not, salt will kill worms, as well as alcohol, seafood (squid, clams and octopus) do not have worms.
Pathogens anisacidosis people larval development of helminths of the genera: Anisakis, Contracaecum, pseudo-terranova, Hysterothylacium related to Ascaridida Scriabin you don't Schikhobalova, 1940, the family Anisakidae Scriabin you don't Korok, 1945. The definitive hosts of these helminthes are many marine mammals, predatory fish and piscivorous birds, the gastrointestinal tract, which are parasitic in men and women. Therefore, 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 head). At the tip end of the anisacidosis has three lips. The fertilized eggs fall into the water, where it comes out of the larvae, which ingest the first intermediate hosts are crustaceans, krill, often belonging to the family Euphausiidae.
Other hosts include marine fish, molluscs, larger crustaceans feed on small crustaceans. Larvae in body of intermediate hosts are found in the body cavity, on the surface or inside various internal organs and muscles of the fish. They do not contain 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, when they eat the infected intermediate host: fish, crustaceans and molluscs. If greater, the intermediate host of eat smaller, that have infected the larvae, the larvae accumulate in the body larger, predatory fish.
How is infection
People get infected by eating the sea fish and seafood, which contains live larvae. Disinfection of shellfish larvae probably freezing and heating. Normal saline and other solutions used for cooking fish, larvae can remain viable for many days and even months. Freezing fish -18C lead to the death of all larvae within 14 days; -20 ° C they die within 4-5 days; 30 ° C are killed within 10 min. In squid larvae die -40C in 40 min.; at-32C for 1.5 hours; -20C day.
In the united states and the Netherlands, sanitary rules regulated by freezing the fish, which will be later heat treatment, 20C for 5 days.
Larvae can tolerate water temperature is +45C. At a temperature of +60C and before they die within 10 min, Thus, Smoking fresh fish temperature range +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 comes one of the most important problems of medical Parasitology. To date, the infestation is registered in many countries in Europe, North and South America and Southeast Asia.
The prevalence of people have a strong tendency to increase in connection with increase in the consumption of marine fish, shrimp, octopus, squid and other sea foods, as well as common with the improvement of the diagnosis of this disease. In 1987 in Germany was a serious precedent, which is associated with the detection of live larvae of the finished products from Atlantic herring.
Many marine fish infected with the larvae. For example, 25 to 100% of the population, halibut, flounder, salmon, cod, herring and other fish of the Okhotsk sea influence them. Do not lower the level of contamination and the fish in the Pacific and Atlantic oceans. The prevalence of squid in the pacific ocean reaches 28%. When you catch a fish larva, which was the digestive system, quickly and actively move from there to other organs (muscle, eggs, milk). So the gutting and cleaning of fish and seafood in the shortest possible time after their catch dramatically reduce the likelihood of contamination of edible parts.
When released in the gastro-intestinal tract of humans, the larvae actively head the mucosa and submucosa of the entire process of the pharynx the colon. Most often they are found in the walls of the stomach and the small intestine. Spot the penetration of larvae is inflammation, accompanied by eosinophilic infiltration, edema. Further, the formation of eosinophilic granulomas, necrosis and perforation of the intestinal wall. Anti-inflammatory and neuro-reflex reactions can lead to bowel obstruction. Sometimes the larvae migrate to the gall bladder, the ducts of the liver and pancreas, making these organs 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 disease symptoms caused by toxic and allergic effects on the larvae of helminths on the human body, including as a result of the formation of granulomas, can be detected for several months or even years.
Symptoms and treatment
The incubation period varies from several hours for 7-14 days. In many respects the clinical picture, symptoms Anisacidosis due to the localization of the parasite. When you find the larvae in the intestine, and symptoms can be quite scarce. Gastric localization (the most common form of the disease) patients worried about severe pain in the epigastrium, nausea, vomiting, sometimes with blood. It should be noted subfebrile or febrile fever, the development of allergic reactions immediate type (urticaria, angioedema). In the case of backward migration of the larvae from the stomach to the esophagus you have symptoms, such as pain and irritation in the throat, cough. Intestinal infection, patients complain of pain in the umbilical region and right iliac region, and rumbling in the stomach, flatulence. You may experience symptoms of acute abdomen, characterized by acute appendicitis or intestinal obstruction. The disease can be acute, subacute or chronic.
Serious complications of intestinal parasites include perforation of the intestinal wall and penetration of the intestinal contents in the abdominal cavity with the development of peritonitis.
Diagnosis and differential diagnosis
Larvae may be detected by contrast radiography and endoscopy or the study of infection of the surgical operations section of the stomach and intestines. When fibrogastroduodenoscopy in the field the introduction of worms, revealed mucosal edema with multiple blood blisters erosions. The study of blood revealed a moderate leukocytosis and eosinophilia. Serological diagnostic methods have not been developed. If coproscopic larvae, eggs or larvae were not observed. The identification of parasite genus and species possible to study maggots, to remove endoscopy or surgery.
Anisacidosis should be differentiated from peptic ulcer and 12 duodenal ulcer, gastritis, pancreatitis, cholecystitis and tumors. The intestinal form, it is necessary to rule out appendicitis, diverticulitis, tumors, colitis and enterocolitis.
Treatment of parasites, rather weakly developed. Is a small development effectiveness of special preparation. But it is not clear systems. Again, there is no clear treatment should be warned fish lovers and limited to use only after heat treatment.