Nematodes - helminthic infections caused round parasitic worms (nematodes). Adult nematodes parasitic more frequently in the gastrointestinal tract of man, but may occur in other organs. The larvae of many nematodes circulate in the blood. Females after fertilization lay eggs released from intestinal nematodes in the external environment with faeces, out-intestinal - with sputum and other ways. In the environment under favorable conditions of temperature and humidity, when the access of oxygen in the eggs are formed larvae and eggs have become contagious. Person contracts nematodosis ingestion of food and water contaminated eggs nematodes, as well as through dirty hands. Some nematodes (Ancylostoma, some, Strongyloides) larvae emerge from the eggs and live in the soil. They can actively introduced into the human body through intact skin. Once in the human body, the larvae develop into adult parasites. There are nematodes (filaree, Guinea worm and other), emerging with the change of owners - final, which live adult parasites, and intermediate, whose larvae live. People most of the nematode is the final host, intermediate serve different kinds of animals and insects. Human infection may by eating fish, water, etc. contaminated with the eggs or larvae of nematodosis, as well as by the bite of blood-sucking insects, which is the intermediate host these worms (filaria). For Trichinella one and the same body is final and intermediate host. A person infected with trichinosis, eating the flesh of pigs, and other animals that are the owners of Trichinella.
Nematodes isolated in humans in their metabolic products that cause sensitisation of the body with the subsequent development of allergic reactions. Sensitization of the body increases with the death and decay of nematodes in the body of the owner. Perhaps as a direct toxic effects of nematode that causes disorders of the nervous system and other organs. Some nematodes (Ancylostoma, some), feeding on the blood of the patient, leading to the development of secondary anemia.
In the USSR a person registered the following nematodes: ascariasis, trichocephalosis, trichinosis, hookworm, necatoroz, strongiloidoz, trichostrongylosis, enterobiasis and other as the development of eggs and larvae of nematodes in the environment occurs under certain climatic conditions, most nematodosis (ascariasis, trichocephalosis) are natural and endemic diseases associated with specific, sometimes large areas. Some nematodes (hookworm, necatoroz) are found only in areas with hot climate, in the USSR - in the Caucasus and some regions of Central Asia. Enterobiasis has widespread.
Prevention of nematodosis is carried out by carrying out of sanitary-hygienic measures, health education of the population, mass treatment of infested nematodes, and the observance of rules of personal hygiene.
Cm. also Ascariasis, Helminthiasis, Trichinosis, Trichocephalosis, Enterobiasis and other