Parasites are divided in appearance into different species. There are also separate groups that combine in their composition different types of parasites. Among the main groups of helminthiases the following are distinguished:
- Parval, caused by bandworms.
- Intestinal, caused by ribbon and round worms, nematodes, which live mainly in the gastrointestinal tract.
- Extraintestinal, which includes worms that can multiply in different organs of a person.
The most common of the extraintestinal helminthiases are clonorchiasis, fascioliasis, opisthorchiasis, paragonimosis. The causative agent of the clonorchosis is the Chinese trematode, a tapeworm reaching 20 mm in length. In the human body, eggs of worms penetrate through eating contaminated carp fish, mollusks, freshwater crayfish. Transmitters of extraintestinal worms can be infected people and carnivores. The causative agent of fascioliasis is the hepatic and giant trematode.
The source of extraintestinal helminthiosis is contained in human feces, animals infected with parasites. Using water from open reservoirs and aquatic plants containing fasciolae larvae, a person becomes infected with parasites. The causative agents of paragonimosis are trematodes of ovoid form with spines all over the surface. Infection of a person occurs when eating crayfish and crabs, invaded by metacercariae P. Westermani.
Extraintestinal helminths
Infection with paragonimosis leads to the colonization of the larvae of the pleural cavity and lungs, and sometimes the brain. Three months later the worms mature and excrete the eggs into the external environment. Around the parasites cavities are formed, which after a while are calcified and fibrous. At an early stage of infection with extraintestinal worms, signs that are characteristic of enteritis, hepatitis and peritonitis develop. In the future, the lungs are affected with an increase in temperature up to 39 ° C, a cough with sputum and an admixture of blood, shortness of breath, chest pains and pulmonary hemorrhages.
The absence of treatment for extraintestinal helminthiasis can lead to pneumosclerosis and the symptomatic complex of the pulmonary heart. When penetration of eggs of nematodes into the brain, the development of the syndrome of the volumetric process is possible. The pathogenic picture of fascioliasis is characterized by the development of cholangitis, subhepatic jaundice, and liver abscesses. The failure to take measures threatens serious violations in the normal functioning of the liver, digestive disorders, and exhaustion of the body. The fasciolae through the intestinal mucosa penetrate the liver and bile ducts, where ripening occurs and after a few months eggs are released. It is also possible to move worms into the lungs, abdominal cavity and other tissues. At achievement of a chronic stage and development of complications at an extraintestinal helminthiasis, very serious consequences for human health are possible.
Tissue worms
Tissue helminthiasis or otherwise pulmonary helminth is the causative agent of eosinophilic meningitis. Migrating through the brain, the living causative agent of extraintestinal helminthiasis affects the tissues in large amounts on its way. Upon reaching the central nervous system, they die, causing inflammation of the meninges.
Gnathostomosis, representing another type of tissue helminthiasis, is caused by intestinal parasites of carnivores. With the feces of these animals, eggs are excreted, from which larvae appear in the water, which serve as food for cyclopeans. In turn, they are eaten by ducks and inhabitants of freshwater reservoirs. Getting through these carriers into the human stomach, the larvae migrate to the chest, subcutaneous tissues and into the eyes. In this case, extraintestinal helminthiasis can initiate fever, hives, leukocytosis. Even a fatal outcome is possible with a cerebral hemorrhage.