YAWS, the name in use in the British West Indies for a con tagious inoculable tropical disease, running a chronic course and characterized by a peculiar eruption, together with more or less constitutional disturbance. It is known by various local names in different parts. The name framboesia was first given to the disease by Sauvages in 1759 from the likeness of the typical excrescences to a raspberry. Yaws was long thought to be peculiar to the African negro, but a disease the same in every respect has long been known in the East Indies, affecting the Malays rather than the negroes, its chief seats being Amboyna, Ternate, Timor, Celebes, Java and Sumatra. It has been identified by De Rochas and other observers in New Caledonia and Fiji.
The general course of the disease is as follows. In children (who form a large part of the subjects of yaws) there will probably be early rheumatic pains in the limbs and joints, in adults the eruption is often the first sign. The eruption begins as small pimples that have a whitish speck on their tops, grow rapidly and reach some half-inch in diameter. The pustules then break and a thick viscid ichor exudes and dries upon them as a whitish slough and around their base as a yellowish-brown crust. Beneath the slough is the raspberry excrescence or yaw proper, a reddish fungous growth with a nodular surface. The favourite seats of the eruption are the forehead, face, neck, arm-pits, groin, genitals, perinaeum and buttocks. Hairs at the seat of a yaw turn white. In young children or infants the corners of the mouth ulcerate, as in syphilis, and the perineal excrescences resemble condylomata. Aetiology.—Yaws is a highly contagious disease. It is neither hereditary nor congenital. The disease spreads by contact with previously infected cases, and it has been proved by experiment that infection may be conveyed by flies, carrying infective material from a yaws sore to an ordinary ulcer. The virus must
be introduced directly through a breach of the skin or mucous membrane; an attack in childhood gives a large degree of im munity for the rest of life. In 1905 Aldo Castellani demonstrated in yaws the presence of a slender spirillum, which he named the Spirochaem pertenuis or Spirochaeta pallidula. It was also ex perimentally proved by him (I) that the material taken from persons suffering from yaws and containing the Spirochaeta per tenuis is infective to monkeys; (2) that when the Spirochaeta pertenuis is removed by filtration the material becomes inert; (3) that the injection of blood from the general circulation of a yaws patient gave positive results in monkeys; (4) by means of the Bordet-Gengou reaction it is possible to detect specific yaws anti bodies and antigen.
The prophylaxis consists in the segregation of the patients suffering from the disease, the antiseptic dressing of the erup tion, the application of a covering to protect it from flies, and the thorough cleansing and disinfection of infected houses and clothing, even the demolition of houses in endemic centres, and finally compulsory notification to the local sanitary authority.
As regards treatment, the malady in a person of good con stitution runs its course and disappears in a few weeks. When the eruption is declared, iodide of potassium and arsenic are very beneficial. As external applications, weak lotions of zinc or car bolic acid may be used, and, if the excrescences are irritable, a watery solution of opium. In 7,157 West Indian cases treated in various hospitals there were only 185 deaths, a mortality of 25.8 per thousand (Nicholls).