Medical helminthology is concerned with the study of helminthes or parasitic worms. Helminthes are trophoblastic metazoa (multi-cellular organisms). Helminthes are among the common parasitic causes of human suffering. They are the cause of high morbidity and mortality of people worldwide. They cause different diseases in humans, but few helminthic infections cause life- threatening diseases.
They cause anemia and malnutrition. In children they cause a reduction in academic performance. Helminthes also cause economic loss as a result of infections of domestic animals. There is age dependent distribution of infections from geo-helminthes and schistosomes. As a result of predisposing behavioral and immunological status, children disproportionately carry the burden of schistosomes and geo-helminthes.
The sources of the parasites are different.
Exposure of humans to the parasites may occur in one of the following ways:
1. Contaminated soil (Geo-helminthes), water (cercariae of blood flukes) and food (Taenia in raw meat).
2. Blood sucking insects or arthropods (as in filarial worms).
3. Domestic or wild animals harboring the parasite (as in echinococcus in dogs).
4. Person to person (as in Enterobiusvermicularis, Hymenolopis nana).
5. Oneself (auto-infection) as in Enterobiusvermicularis. They enter the body through different routes including: mouth, skin and the respiratory tract by means of inhalation of airborne eggs.
The helminthes are classified into three major groups.
These are: 1. Trematodes (Flukes)
2. Nematodes (Round worms)
3. Cestodes (Tape worms). The Trematodes and Cestodes are groups of flat worms.