A New Study Accelerates the Progress Towards the End of Yaws Disease

The study published in the New England Journal of Medicine identifies a more efficient strategy for yaws eradication


A new study published in the New England Journal of Medicine corroborates the greater efficacy of a new strategy for the elimination of yaws compared to that established by the World Health Organization (WHO). The study was led by Oriol Mitjà, from the Germans Trias i Pujol Hospital and the Fight AIDS and FLS and Lucy John, from the Public Health Division of the National Department of Health of Papua New Guinea (PNG).

In 2012 Mitjà and his team, researchers at ISGlobal, laid the scientific foundations for the WHO to establish the Morges Strategy, aimed at achieving yaws eradication through the implementation of one round of massive administration of azithromycin to all the people residing in areas where cases have been recorded. However, in 2018 it was found that the WHO strategy was insufficient to stop the transmission of the infection.

The recently published article shows the results of a community-level clinical trial carried out between April 2018 and October 2019 in the province of New Ireland (PNG). It compares the current WHO strategy (Morges), based on a single round of massive distribution of azithromycin followed by the targeted treatment of persistent yaws cases, and an experimental strategy, consistent on three rounds of mass distribution six months apart. The trial included 57,000 inhabitants of an area with a high prevalence of yaws, randomly assigned to one of the two intervention arms.

The study clearly establishes the benefits of the experimental arm compared to the control: eighteen months after the start of the study, the prevalence of yaws was four times lower in the group that received three rounds of azithromycin (0.04%), compared to the group that received a single round (0.16%). These results outline the steps to be followed to achieve effective eradication of the disease.

The funding for the study was provided by the “la Caixa” Foundation, the Barcelona Provincial Council and the Fundació Barberà Solidària. The azithromycin required to conduct it weas donated by Kern Pharma.


John L, Beiras C G, Houinei W, Medappa M, Sabok M, Kolmau, et al. Trial of Three Rounds of Mass Azithromycin Administration for Yaws Eradication. New England Journal of Medicine. 2022; 386:47-56. DOI: 10.1056/NEJMoa2109449