Yaws - A Review of Clinical Features, Diagnosis and Treatment

Abstract

Yaws, a neglected tropical disease caused by Treponema pallidum subsp. pertenue, primarily affects children in impoverished rural areas. It is spread through direct skin contact. The disease progresses through clinical stages. In the primary stage, patients develop a, usually painless, papilloma or ulcer, often on the lower extremities, which is highly contagious. If untreated, this lesion heals spontaneously but may progress to secondary yaws, characterised by disseminated skin lesions, scaly papules and painful hyperkeratotic plaques on the palms and soles. Tertiary cases occur in 10% of untreated individuals and can cause severe disfigurement, but with the wider availability of treatment this is rare today. Though yaws can be treated with benzathine penicillin, oral azithromycin has become the preferred treatment due to its ease of administration. Currently, it is known to be endemic in 16 countries, with the majority of cases found in the Western Pacific, followed by West Africa and parts of South East Asia. The World Health Organization has renewed eradication efforts, targeting global eradication by 2030 through mass drug administration (MDA) campaigns and enhanced diagnostics. However, challenges such as emerging azithromycin resistance, difficulties in achieving high MDA coverage, and potential zoonotic transmission from nonhuman primates threaten progress. Accurate diagnosis is critical, especially in distinguishing yaws from similar skin conditions and ensuring all endemic communities are identified and offered treatment. Strengthening surveillance and enhancing laboratory capacity for molecular diagnostics is essential for the success of the eradication campaign. With sustained effort and innovation, the global eradication of yaws by 2030 remains achievable.