Yaws Health Dictionary

An infectious disease that tends to be found throughout poorer subtropical and tropical areas of the world. Yaws is caused by a spirochaete (a spiral-shaped bacterium), and it spreads principally in conditions of poor hygiene. The infection is almost always acquired in childhood, and it mainly affects the skin and bones.

The bacteria enter the body through abrasions in the skin. Three or 4 weeks after infection, an itchy, raspberry-like growth appears at the site of infection, sometimes preceded by fever and pains. Scratching spreads the infection and causes more growths to develop elsewhere on the skin. Without treatment, the growths heal slowly over the course of about 6 months, but recurrence is common. In about 10 per cent of untreated cases, widespread tissue loss eventually occurs. This may eventually lead to gross destruction of the skin, bones, and joints of the legs, nose, palate and upper jaw.

Yaws can be cured by a single large dose of a penicillin drug given as an injection into muscle.

A non-venereal spirochaetal infection caused by Treponema pertenue ; it was formerly widespread in most tropical and subtropical regions amongst the indigenous population, ?orid disease being more common in children than adults. The term is of Carib-Indian (native to north-eastern South America, the east coast of Central America, and the lesser Antilles) origin. It is directly contagious from person to person; infection is also transmitted by ?ies, clothing, and living in unclean huts. Clinically, the primary stage is characterised by a granulomatous lesion, or papule (framboesioma or ‘mother yaw’) at the site of infection – usually the lower leg or foot; this enlarges, crusts, and heals spontaneously. It appears some 2–8 weeks after infection, during which time fever, malaise, pains, and pruritus may be present. In the secondary stage, a granulomatous, papular, macular or squamous eruption occurs; periostitis may also be present. The late, or tertiary stage (which appears 5–10 years later), is characterised by skin plaques, nodules, ulcers, hyperkeratosis (thickening of the skin of the hands and feet) and gummatous lesions affecting bones. Recurrence of infection in individuals suffering from a concurrent infection (e.g. SYPHILIS or TUBERCULOSIS) renders the infection more serious. Diagnosis is by demonstration of T. pertenue in exudate from a suspected lesion. Treatment is with PENICILLIN, to which T. pertenue is highly sensitive. Extensive eradication campaigns (initiated by the WHO in 1949) have been carried out in endemic areas; therefore, the early stages of the infection are rarely counted; only tertiary stages come to the attention of a physician. Failure of surveillance can lead to dramatic local recurrences.

A non-venereal disease caused by Treponema pertenue and characterised by skin and bone lesions similar to those seen in secondary syphilis. The disease is caused by a spirochaete morphologically, immunologically and serologically identical to Treponema pallidum, the cause of syphilis. Yaws is clinically very similar to another nonvenereal treponematose, pinta, caused by T. carateum and found in South America and the Caribbean.

(pian, framboesia) n. a tropical infectious disease caused by the spirochaete Treponema pertenue in the skin and its underlying tissues. Yaws occurs chiefly in conditions of poor hygiene. It is transmitted by direct contact with infected persons and their clothing and possibly also by flies of the genus Hippelates. The spirochaetes enter through abrasions on the skin. Initial symptoms include fever, pains, and itching, followed by the appearance of small tumours, each covered by a yellow crust of dried serum, on the hands, face, legs, and feet. These tumours may deteriorate into deep ulcers. The final stage of yaws, which may appear after an interval of several years, involves destructive and deforming lesions of the skin, bones, and periosteum (see also gangosa; goundou). Yaws, which commonly affects children, is prevalent in hot humid lowlands of equatorial Africa, tropical America, the Far East, and the West Indies. It responds well to antibiotics.