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Seatworm (Oxyuris vermicularis).

This is a small worm of a whitish color, being from one-sixth to one-half inch long. It is found mostly in the lower portion of the bowel where it causes intense itching when it crawls out through the opening.

Symptoms. The itching is worse at night. The skin may become inflamed and reddened through scratching to relieve the itching and considerable pain of a burning or bearing down character may be present. The condition may seriously interfere with sleep. Inspection of the stools will show the presence of the white threadlike parasites.

Prevention.-Persons become infected by swallowing eggs that may be present in drinking water or upon uncooked food and fruit that has come in contact with the hands of infected persons. The eggs may be embedded under the nails of ignorant and unclean persons who may infect themselves and other persons.

Treatment.-A purgative should be taken to drive the parasite into the lower bowel, and after this acts an injection consisting of a decoction of quassia bark should be given into the rectum. This decoction is made by boiling 1 or 2 ounces of the bark in a pint of water. The underclothes should be changed and boiled and the person's skin should be washed with a solution of carbolic acid prepared by dissolving half a teaspoonful of carbolic acid in a pint of boiling

water.

Hookworm (Nercator americanus).

Hookworm disease is due to small, round worms which attach themselves to the lining membrane of the intestine, suck the blood, and cause the condition of anemia and emaciation which are such marked features of the complaint. The disease is due to a poison produced by the worm.

The life history of the worm is described by Stiles as follows:

LIFE HISTORY.-The adult hookworms live in the small intestine, occasionally in the stomach. They mate in the bowels, and the females deposit numerous eggs. The eggs do not, however, undergo full development until they are discharged with the fecal material from the host. Thus every individual hookworm found in the intestine represents infection with a separate germ.

FREE LIFE. After a short time (eight hours to several days), the period varying according to conditions of heat and moisture, a tiny embryo develops in each egg. This embryo breaks through the eggshell and feeds on the ground or in the night soil. In the course of two days or so the embryo sheds its skin, but continues to feed. After about a week the worm sheds its skin again, but continues to live inside of its discarded skin, and it no longer takes any food. During this development, the rapidity of which may vary according to circumstances, the worm undergoes a growth in addition to certain changes in structure. The worm which lives in its second cast-off skin represents the

LH WILDER

infecting stage which enters man and is sometimes called the "encysted stage." It may live in this condition for five months, perhaps longer.

MODE OF INFECTION.-Infection may occur in two different ways, namely, per mouth or per skin.

Mouth infection.-Formerly infection by mouth was supposed to be the only method by which the worms entered the human body. Then when the method extreme, and there was

of skin infection became known opinion went to another a tendency to ignore or minimize the mouth infection. Opinion is now moving back again in the other direction, and indications are accumulating to support the view that infection by mouth is by no means rare or exceptional.

Skin infection.—If in the infecting stage it gets upon the skin, either of persons who go barefooted or who handle infected dirt, the worm bores its way into the pores, as into hair follicles, and escapes from its surrounding sheathlike skin. It then starts on its passage through the body. It may enter the blood, pass through the heart, filter out in the lungs, crawl up the trachea, down the esophagus, through the stomach, and find its way to the small intestine. In laboratory experiments on animals the worms may be found in the intestine 8 to 14 days (possibly earlier) after the skin infection has been practiced. Arriving in the intestine, the worm sheds its skin two more times, becomes adult and mates, and Looss has proved in the case of the Old World hookworm that eggs may be found in the stools 71 days after infection.

Claude Smith found eggs in the feces six and one-half weeks and seven weeks after experimental skin infection on two persons with the American parasite.

Symptoms. While the worms are working their way through the skin, an intense itching is produced, which is called "ground itch." Small vesicles occur at the point of entrance, the skin becomes reddened and is usually covered with scratch marks, due to the patient's effort to relieve the itching. This is the first stage of the disease. Later, when the worms reach the intestinal tract, the patient becomes pale and thin. Children are undersized, with large bellies; they are stupid and backward in their lessons at school. Their appetite is perverted, patients often eating clay, plaster, cotton, and other indigestible substances; there is pain and tenderness in the abdomen; constipation is common; stools are clay colored and may be streaked with blood. The afflicted person tires easily and gets out of breath from slight exertion. Dizziness and headache are not unusual symptoms.

Prevention.-Hookworm disease is a disease of rural communities. It is prevented by providing a safe means for the disposal of human excreta. (See p. 39.) The habit of going barefoot in warm climates greatly increases the liability of contracting infection. The treatment consists mainly of the administration of thymol, but this should only be taken under the direction of a physician.

SYPHILIS.

Syphilis is a constitutional disease, caused by a microorganism called Spirochete pallida. It is communicable and is usually acquired during sexual contact. It may, however, be contracted in many different ways, direct and indirect. It begins by a primary

lesion or sore, called a chancre, at the seat of inoculation (where the virus enters), and is followed by eruptions of the skin of different forms and different degrees of severity and variable duration. Sores also appear at the angle of the mouth and mucous patches develop on the lips, tongue, inner sides of the cheeks, and sore throat is often present. Mucous patches or syphilitic warts are also frequently seen about the anus or in any region where the skin is moist. The hair frequently falls out, the eyes are sometimes seriously involved, and sooner or later every organ in the body may become affected.

The primary or initial lesion of syphilis (the hard chancre) usually appears about 3 weeks after exposure, but may be as early as 10 or 12 days or as late as 5 or 6 weeks. It begins as a red spot or papule, which usually breaks and forms a small ulcer with hard edges. Sometimes the sore appears as a simple excoriation or superficial ulcer without hard edges. The neighboring glands become in the course of a week or two enlarged and hard. They seldom suppurate. About two months later the skin eruption and other secondary symptoms begin. The lymph glands above the elbow, along the side and back of neck, and all over the body are usually enlarged. Patient frequently complains of headache and pain in the limbs, always worse at night, and may have slight, occasionally considerable, fever.

Prevention.-A man suffering from syphilis in an active form should be compelled to use separate drinking cups, knives, spoons, forks, towels, etc. These articles should be disinfected by boiling or by one of the solutions described on page 104. He should under no circumstances smoke the pipe belonging to another man or allow another man to smoke his. He should sleep in a separate bed and all his belongings should be kept strictly to himself, for unless the greatest care is taken other persons may contract the disease from him. Chancre of the lip may be acquired by smoking the pipe of a syphilitic. No one suffering from syphilis should kiss or fondle another person, as he is liable to convey the disease to that person. Treatment. For the primary sore bathe the part with soap and water and dust boric acid over it twice a day.

If secondary symptoms, eruptions of skin, etc., appear, give a pill of protiodide of mercury, one-sixth grain, three times a day. Salvarsan, diarsonal, or some other similar arsenical preparation is the best remedy for the disease, but this medicine can only be given by a physician. The mouth and teeth should be kept clean by means of a soft toothbrush and Castile soap and water, or water to which a small quantity of bicarbonate of soda (baking soda) or tincture of myrrh has been added. If mucous patches appear in the mouth, smoking must not be allowed. After dressing a syphilitic sore, a person should wash his hands carefully with soap and water and then in a disinfecting solution. (See p. 185.)