Parasitic Disease

Parasitic Disease in Man. The parasites which are met with in the human subject may be divided into those belonging to the animal and those belonging to the vegetable kingdom. The former include certain members of the tapeworm family [Tapeworms, Hydatid], a number of nematode worms (the common round worm, the threadworm, trichina spiralis), and others. There are, moreover, a number of skin parasites, the itch insect and three varieties of pediculus being included among these. The organism of malaria has recently been declared to belong to the class of protozoa, and it is not unlikely that other members of this class are concerned in the production of disease in man. The vegetable parasites consist of the fungi which are associated with some forms of skin disease (ringworm, favus, pityriasis, etc.). There is also the ray fungus which is the cause of the disease known as actinomycosis, and the fungus of Madura foot. All these parasites are members of the various groups of fungi; but by far the most important vegetable parasites are those which belong to the lowest group, the fission fungi. [Bacteria.]