Diphyllobothrioses (synonym for botriocephalosis) are helminth infections caused by large tapeworms belonging to the genus Diphyllobothrium. The most widely distributed is Diphyllobothrium latum - a wide ribbon (fig.). Its body can reach a length of 7–9 m and consists of a set of segments, each of which has an independent system of male and female genital organs. At the head end there are two deep slits (bothria), through which the parasite is attached to the host tissues. Adults parasitize in the small intestine of humans, cats, dogs and some wild animals. After fertilization, they begin to produce eggs that are released to the outside with the host feces. Eggs develop only in freshwater. A larva (coracidia), covered with cilia, emerges from the egg, which, being swallowed by a copepod, Cyclops, develops in his body into a larva of the second stage, the procercoid. Further development of the percercoid occurs in the fish, swallowing the larva along with the cyclops. Predatory fish can also become infected by eating smaller fish containing larvae. In the body of the fish, the larvae reach the invasive stage (plerocercoids). They are localized in the muscles and on the surface of the internal organs. When the human and other definitive hosts are swallowed by plerocercoids, adult parasites develop in their body in 18-20 days.Go
Epidemiology. The foci of diphyllobothriasis are located near freshwater bodies of water. In foci near small lakes, the prevalence of population is usually higher than in foci located near major rivers. In the USSR, the foci of diphyllobothriasis are concentrated mainly in the basin of the rivers Ob, Irtysh, Lena, Yenisei, the lower reach of the Amur, Svir, Pechora, Neva, on the Lower Volga, on the lakes Baikal, Ladoga, Onega .
A person becomes infected with diphyllobothriasis by eating poorly cooked (roasted) or raw fish (pike, burbot, ruff, perch), in the tissues of which there are wide tapeworm larvae. Especially often the larvae come from fresh, slightly salted caviar pike and burbot. Infection is often seasonal in nature and is associated with the spring Putin.
The spread of invasion is largely dependent on poor sanitary conditions of the area and contamination of water bodies with faeces as a result of the discharge of untreated or poorly treated sewage into the water , discharge of sewage from steamers and other types of river transport, when leaking liquid from cesspools, during bathing wash clothes, etc.
Pathogenesis. The tape-worm has a sensitizing and mechanical effect on the host. In some cases, it causes the development of anemia of the pernicious type, which is based on a parasite-induced metabolic disorder of vitamin B12 and folic acid . In the development of anemia, the state of the patient's body, the nature of its nutrition, and the living conditions are of great importance.
The clinical picture (symptoms and signs). Diphyllobotriasis often occurs with mild symptoms: weakness, dizziness, drooling, nausea , vomiting , abdominal pain, diarrhea, or alternating diarrhea and constipation . Often, bright red painful spots and cracks appear on the tongue. Achilia develops, the stool is unstable, the liver and spleen are enlarged. Megaloblasts in the blood, occasionally normoblasts, aniso- and poikilocytosis and polychromatophilia. Color indicator is high. The diagnosis is made on the basis of the detection of the eggs of the tapeworm in the faeces (see Helminthological research methods).
The treatment of diphyllobothriasis is specific and pathogenetic. In severe cases of anemia, pathogenetic therapy should begin before deworming. Vitamin B12 is administered intramuscularly at 100–200 mcg per day for 3-4 weeks, in the first week every day, then every other day. Specific therapy is carried out by phenasalum, administered once in a dose of 2 g (children 0.5-1.5 g) in 1/4 glass of water at night, or dichlosalom (2 g phenasal +1 g dichlorophene) according to the same method. Effective ether extract from the rhizome of male fern adults at a dose of 4-5 g. One hour after taking the fern - saline laxative, 1-2 hours after the laxative - a light breakfast. If there are contraindications (decompensation of cardiac activity, ulcerative processes in the gastrointestinal tract, liver and kidney diseases, pregnancy ), pumpkin seeds or acriquine are prescribed.