Prophylaxis.—As for boils.
Treatment.—The spread of ulcers can be checked by removing the hairs from their bases and round their margins. Very often the ulcer can be started on its healing process by employing dressings soaked in a solution of 1.5 per cent. sodium citrate and 20 per cent. common salt. Vaccines are often successfully used in this condition, and the stannoxyl mentioned under boils may be employed, as may a salicylic acid ointment, 20 grains to the ounce.
Sleeping Sickness.
This is the old “Negro lethargy,” and must not be confounded with what is now called sleeping sickness in the British Isles and on the Continent, which is quite a different disease. True sleeping sickness is limited to Africa, and there are two chief types: that occurring in parts of the West Coast and the French and Belgian Congos, in Angola, in portions of the Anglo-Egyptian Sudan, in Uganda, and in parts of the Tanganyika territory; and that which occurs in Northern Rhodesia, Nyasaland, Portuguese West Africa, and the region of the Rovuma River.
Cause.—The cause is a tiny animal blood parasite conveyed from the sick to the healthy by certain species of tsetse flies. In the tsetse fly the parasite, which is called a trypanosome, undergoes a definite development.
The two species of tsetse fly meriting special consideration here are Glossina morsitans and Glossina palpalis. The former, as a rule, occurs in thin, deciduous bush, or low, comparatively open forest, while the latter haunts the neighbourhood of streams and lakes, and is rarely found any great distance from the water edge. These flies are about the size of a small blue-bottle, but are not so stoutly built and, when closed, their wings overlap and project beyond the end of the abdomen. Glossina morsitans is brownish coloured, with bands on its abdomen. Glossina palpalis is much darker, indeed almost black-looking. They have a quick and darting flight, and are attracted by rapidly-moving objects, like motor-bicycles and motor-cars. Once they alight they do not move about. As a rule they bite only during the day, but they may attack man on bright moonlight nights.
Symptoms.—The incubation period is probably about three weeks. The fly bite may be painful; and causes a slight local irritation. The disease begins insidiously, with an irregular fever, and there may be a skin eruption. The fever comes and goes, and the patient gets weaker and suffers from headache. The glands in his neck and possibly in other parts of his body become enlarged and may be tender. The first stage of the disease is called trypanosome fever, and may end in recovery. More usually the central nervous system becomes affected, and then the symptoms of true sleeping sickness develop, slowly or with considerable rapidity. The patient becomes dull and drowsy. Both his speech and movements are affected. His face gets puffy, and he shuffles when he walks. He still has fever, continues to lose flesh, and gradually passes into a sleepy condition, which may be associated with convulsions. Saliva dribbles from the lips, and half-masticated food may remain in the mouth. The patient becomes helpless and indifferent to his surroundings, and either dies from coma or from some intercurrent disease, such as pneumonia or dysentery.
Prophylaxis.—Personal prophylaxis consists in avoiding being bitten by tsetse flies. When passing through fly belts in affected areas veils and gloves may be worn.
Treatment.—If taken in time sleeping sickness can be readily cured by the use of the arsenical preparation atoxyl, combined with antimony. The course of treatment, however, extends over a considerable period, and it must be carried out under the supervision of a medical man.