New Lancet Global Health paper reveals global prevalence of yaws

Findings show highest burden exists in Papua New Guinea, Solomon Islands and Ghana.

1 June 2015

A new paper in The Lancet Global Health synthesises the number of people with yaws at national and sub-national levels and estimates populations at risk of contracting this neglected tropical disease.

Yaws is a neglected tropical disease caused by skin-to-skin contact with an infective lesion. It causes painful swelling, hardening and breaking up of the skin, and after years of infection the bones and joints can also become misshapen and painful, leading to fatigue. Highly contagious and especially common among children, the infection can become latent at any time and relapses can occur for up to 5–10 years.

To estimate yaws prevalence, authors searched data repositories like PubMed and WHO to identify published, unpublished and ongoing datasets of prevalence of active and latent yaws from 1990 to 2014. To calculate at-risk populations, authors used total population data and yaws incidence data from national programmes from 2010 to 2013.

Findings showed a prevalence of active yaws infection that ranged from .31% to 14.5% in yaws-endemic areas, and prevalence of latent infection ranged from 2.5% to 31%. Between 2010 and 2013, WHO received 256,343 reports of yaws cases from 13 endemic countries. As much as 84% of these reports were from Papua New Guinea, Solomon Islands and Ghana. Lastly, authors estimated that over 89million people were living in yaws-endemic areas in 2012.

Authors recommend the three countries reporting the highest numbers of yaws cases should be the focus of control efforts including implementation of WHO’s eradication strategy. They also recommend mapping and surveillance as part of control activities.


Oriol Mitjà, Michael Marks, Diby J P Konan, Gilbert Ayelo, Camila Gonzalez-Beiras, Bernard Boua, Wendy Houinei, Yiragnima Kobara, Earnest N Tabah, Agana Nsiire, Damas Obvala, Fasiah Taleo, Rita Djupuri, Zhang Zaixing, Jürg Utzinger, Lase S Vestergaard, Quique Bassat, Kingsley Asiedu

Read the paper in the Lancet Global Health

Read commentary by Prof. David Mabey, London School of Hygiene & Tropical Medicine