PARASITIC PROTOZOA The discovery of these unicellular organisms as human parasites was made several decades ago. In recent times, many case-reports have been made affirming the presence of these parasites, and the reaction of the organism which harbors them in men and animals. Experimental inoculation in suitable laboratory animals has becn at tempted, and positive results have been obtained. Even if up to the present time no positive evidence that these parasites give rise to intes tinal disease has been furnished, still it remains positive that they find favorable eonditions for existence when intestinal disease is present. It is always conceivable that they may have a part in catarrhal and inflammatory intestinal processes running a chronic course, especially when we consider their rapid and enormous powers of multiplication, their agility, and the products of their metabolism. The fact that We can not obtain pure cultures of the aniceffie, or only with great diffi culty, has prevented, up to the present time, an exact demonstration of their etiological importance. The most CO111111011 protozoa found in children are the following: 1. The A nurba coli (Fig. 34, a, b, c, d). Their appearance resembles that of the large white corpuscles, though the size of the individuals may vary considerably. In the interior of the hyalin-like body are found a nucleus; one to several strongly refractive, periodically appearing and disappearing, contractile vacuoles; and foreign bodies absorbed as food—bacteria, plant cells, red blood-corpuscles, etc. The body is either round or oval, and is altered in shape by the extension anti drawing in of the protoplasm (pseudopod formation). In the e-ncysted condition (Fig. 34, d), the arnceba is round. Its diameter varies between .01 and .03 min. Quincke differentiates several forms of the ameeba, some markedly pathogenic for animals and man, and some not.
2. The Cercoinonas intestinalis (Fig. 35) possesses a pearl-shaped body, which is between .008 and .012 mm. long. It has a short tail thread, and a long flagella at the anterior end of the body.
3. The Triehomonas intestincdis ? Fig. 36), also pear-shaped and from .01 to .015 nam. long, usually has three or four long, tender flagella. at its anterior end and an undulating fringe of cilial. The taidend is short.
1. The Megastomum enterieum (Fig.
37) has a hyaline body surrounded by a delicate membrane; is from .018 to .021 min. long; and has a breadth of .008 to .011 min. It contains two clear vesicles, united with each other in a cavity at the anterior part of the body. Four pairs of flagelle facilitate the movement of this parasite, which usually clings to tbe cells of the intestinal mucous membrane. It is a frequent parasite of mice, by which it is conveyed to food and other objects from which it gains. entrance into the human body.
5. The Balantiditint coil, (Fig. 38), an egg-shaped body thickly covered with cilia, is from .05 to .10 inm. long; and contains, in addition to the food-stuffs., a nucleus and one to three contractile vacuoles. This parasite also becomes encapsulated, which, at times when permanent, admits of its conveyance by dust, water, etc. It is often found in pigs.
The diagnosis of these protozoa is usually easy to make with a microscope. The author recommends the immediate investigation of a small portion of feces, removed with a rectal sound, with the aid, if necessary-, of a heated stage. The differential diagnosis of the individual forms offers no diffieulties.
The therapeutic measures against these parasites are often very simple to carry out: the prevention of intestinal catarrh; the institu tion of a slightly constipating diet—cocoa, chocolate, and dry huckle berries or huckleberry wine, or diluted red wine. Medicines that destroy the parasites are tannalbin, 5 to S grains, three or four times a day; tannate of quinine, one-third to four grains (according to the age of the ehild), three or four thnes a day; calomel in small doses (one sixth to one-third grain), three times a day; thymol (one-half to one per cent. solution) and sulphate of quinine (one to two per eent. solu tions), a teaspoonful to a dessertspoonful every two hours. Intestinal irrigations after previous cleansing enemata should be made with two tenths per cent. quinine or thymol solution or one-half to one per cent. tannin solution, and are useful to destroy the anuelue in the large colon. Otte should be eareful not to use eorrosive sublimate or carbolic acid enemata.
From the prophylactic standpoint, we must not forget that these parasites arc usually taken into the body in an encysted condition, with water, fruit, salad, and other raw vegetables.