The principal and best-known relapsing fever of Africa is that excited by Spirochæta duttoni, and transmitted to man by ticks, chiefly Ornithodorus moubata. The incubation period is usually about seven days but may be longer. The patient is dull and lethargic, perspires freely and is often constipated. The temperature rises to 103° F. or 105° F., there is headache, pains in the back and limbs, general chilliness and great pain in the region of the spleen, which often enlarges. The symptoms become worse, there is a fall of temperature with improvement in the morning, and a rise, with increase of pain, in the evening. Spirochætes are now found in the blood in greater numbers. The symptoms last three to four days and end in a crisis with profuse sweating and fall of temperature below normal. The day before the crisis there is a pseudo-crisis, when the temperature falls but there is no improvement. The patient is left weak and tired. Recovery may follow, but more usually a relapse occurs. The intermission period varies; five to eight days is common. The symptoms of the relapses are like those of the first attack. The number of relapses varies, five to eleven may occur.
The treatment recommended is by salvarsan, as for the European relapsing fever.
With regard to prophylaxis, localities where ticks abound must be avoided and the parasites themselves destroyed. Native huts should be avoided. Mosquito nets, a bed well off the ground and the use of night lights are advised by Manson to avoid attacks by ticks, which are often nocturnal in their habits.
In North Africa (Algeria, Tunis, Tripoli, Egypt), and sometimes in the Anglo-Egyptian Sudan, a spirochætosis due to S. berbera occurs. According to Castellani and Chalmers, the incubation period varies somewhat. The fever reaches its height during the first twenty-four hours, and afterwards shows a morning remission. Jaundice is often absent, but there may be hepatic tenderness and splenic enlargement. One or two relapses usually occur. The treatment is on the same lines as for the other spirochætal fevers. Sergent and Gillot[452] (1911), working at the Institut Pasteur of Algeria, have had good results by using injections of salvarsan in doses of 0·75 to 1·0 cg. per kilogramme weight of the patient. The prophylactic measures are directed against lice and other biting insects. Personal cleanliness is most necessary.
In Asia, a relapsing fever, due to the spirochæte named S. carteri by Manson in 1907, producing a mortality of about 18 per cent., occurs. The symptoms have a general resemblance to those produced by S. recurrentis, but on the fall of temperature to subnormal on the sixth or seventh day, when profuse perspiration and polyuria occur, instead of improvement following, the patient often becomes collapsed, with a clammy skin and feeble pulse. Improvement is slow. The first relapse occurs about the fourteenth day of the attack, when the temperature may be higher than for the first attack. There are seldom more than four relapses. The treatment is by salvarsan, of which doses of not more than 5 gr. intravenously should be given. Sudden heart failure being common, Castellani and Chalmers state that cardiac stimulants should be given. Prophylaxis is the same as for European relapsing fever.
B. Yaws or Frambœsia tropica.
Yaws is essentially a tropical disease, though it is found in the tropical and subtropical zones in all parts of the world, except in the mountains and cold districts. In 1905, Castellani found the causal organism, Treponema pertenue (sometimes called Spirochæta pertennis) (see p. [127]). The disease shows three periods: (1) The primary stage, consisting of the development of the primary lesion or papule, which is usually extragenital. The papule dries into a crust beneath which an ulcer lies. (2) The secondary or granulomatous stage, which commences from one to three months after the primary lesion is first seen. It consists of a general eruption of small papules, some of which enlarge and become granulomatous nodules covered with a yellowish crust. They are common on the limbs and face. (3) The tertiary stage, in which deep ulcerations and gummatous nodules appear. Any of the tissues may be involved. Osseous lesions may occur. The disease does not appear to be hereditary; it is usually spread by contact.
The best treatment appears to be by salvarsan or neo-salvarsan. Castellani and Chalmers recommend intramuscular and intravenous injections. For intramuscular injection an alkaline or neutral solution of the drug is preferable, or a suspension of the drug in oil may be used. The dose varies from 0·3 to 0·5 gr according to the age and sex of the patient. For use intravenously, a slightly smaller dose is required. Galyl is also being used.
In countries where frambœsia is endemic, slight skin abrasions should be carefully treated with antiseptics. Yaws patients should be isolated till cured, and their dwellings and personal possessions disinfected.