A system of practical medicine. By American authors. Vol. 2

by Unknown

The female, which is ordinarily seen alone in the greatest abundance, is a white cylindrical worm tapering toward both extremities. The head end is thickened, and is provided with three prominent labial papillæ enclosing the mouth. The posterior end extends from the anal aperture in a long and straight, narrow, conical, sharp-pointed tail. The double uterine tube, distended with eggs, terminates in a vagina, the external aperture of which is situated ventrally near the anterior third of the body. The smaller male hardly tapers behind, but is incurved and ends in a short, blunt, conical tail. The penis is a single chitinous spicule, the end of which is usually seen projecting from the cloacal aperture.

The young seat-worms, in various degrees of growth and development, and the mature males are chiefly to be met in the lower portion of the small intestine, while the pregnant and mature females chiefly occupy the cæcum.

The seat-worm is exceedingly prolific, it being estimated that a single ripe female contains from 10,000 to 12,000 eggs, and these, it is suspected, may be renewed several times before her functions become exhausted. From time to time the ripe females proceed along the large intestine to the rectum, in which position they lay most of their eggs. These are discharged, together with many of the worms, in the feces.

The eggs are ovoid in shape and about 0.05 mm. long. After they are laid under favorable conditions the embryos are rapidly developed. Left in water, they soon die.

The investigations of the helminthologists of the day make it appear that it is necessary that the eggs of the seat-worm should be swallowed and pass through the stomach, in which the embryos are freed, before they can undergo development to sexual maturity. Moreover, observations go to show that infection may, and probably ordinarily does, occur from eggs scratched from the anus and conveyed to the mouth directly or by being applied to food from uncleanly hands. It is evident that itching of the anus, induced by the presence of the parasites in the rectum, often accompanied by itching of the nose and lips, may lead to alternate scratching of the parts and the transference of eggs from one to the other. Thus, too, uncleanly nurses who may be infested with seat-worms after scratching may handle food and infest children under their charge. Children are commonly more liable to the parasites than others, no doubt from the circumstance that they are less capable of avoiding the conditions favorable to infection. Seat-worms prevail in all conditions of society, but their prevalence is largely proportioned to the more or less uncleanly habits. Persons sleeping with others infested are liable to infection, especially if they are uncleanly and in the habit of eating in bed. Obvious hints to avoid the parasites are obtained by regarding the statements thus given.

SYMPTOMS.—The presence of a few seat-worms is usually attended with no obvious inconvenience, and they may remain unnoticed unless accidentally observed in the evacuations. The symptoms occasioned by them are in great measure proportioned to their quantity and the susceptibility of the patient. The most prominent symptom is excessive itching of the anus; often trifling or even absent during the day, it becomes very annoying and distressing in the evening or during the night. This periodic change appears to be due to the movement of the worms to the rectum, apparently induced by the position and repose of the patient and the increased warmth of the body in bed. Under these circumstances the patient attempts to relieve the incessant itching by scratching, and often by boring with the finger in the anus. In this way eggs become adherent to the finger-nails, under which they have been repeatedly detected, and may thus be inadvertently transferred to the mouth. Occasionally, some of the worms wander from the anus, and in women may thence penetrate into the vulva. The itching of the anus may induce more or less sexual irritation, which in the young may further lead to onanism and its attendant evils. Other symptoms of the presence of the parasites are itching of the nose and lips, restlessness in sleep, grinding of the teeth, startings, twitchings, and general nervous disturbance. When the worms are very numerous they may produce intestinal catarrh, with discharges of mucus, pain, and diarrhoea. In children especially they may give rise to more serious nervous symptoms, as epileptic fits and chorea.

TREATMENT.—Generally, persons are readily relieved of seat-worms. Epsom salt alone or with senna as a purgative, repeated once or twice, often answers to completely expel them. Castor oil, also alone or with a few drops of the oil of turpentine or of wormseed, is also an effectual remedy. The tincture of aloes, in the dose of from half a fluidounce to two fluidounces, once or twice repeated, the writer has found to fully answer the purpose. Besides the purgatives, medicated suppositories, in obstinate cases injections of olive oil, and enemata of a solution of castile soap introduced by means of an elastic tube, so as to wash out the entire length of the large intestine, may be employed.

ASCARIS LUMBRICOIDES.—SYNONYMS: Round-worm; Long round-worm; Maw-worm; Lumbricus.

The round-worm is the largest of the nematodes which ordinarily infest man, and is second only in frequency to the seat-worm. It is a well-known parasite, and prevails everywhere in all conditions of society. It is less lively in its movements than the seat-worm, and is remarkable for possessing a peculiar disagreeable odor, which is independent of the medium in which it lives. It inhabits the small intestine and feeds on the contents. It also infests the hog and the ox.

The round-worm is cylindrical, reddish or brownish, and tapering toward both extremities. The head end terminates in three prominent labial papillæ surrounding the mouth, and the tail end is short and conical. The female, as commonly seen, ranges from six inches to a foot in length, and is about a fourth of an inch in thickness. The ovarian tubes are long, thread-like, and tortuous, and, with the shorter, nearly straight, and wider uterine tubes, contain many millions of eggs. The genital aperture is situated ventrally near the anterior third of the body. The male is about half the size of the female, but is capable of considerable extension, and the tail end is incurved. The penis consists of a pair of slender, clavate, chitinous spicules, the ends of which protrude from the cloacal aperture at the root of the tail.