The Lancet magazine has just published the results of a clinical trial conducted by researchers from ISGlobal that has demonstrated the efficacy of an oral antibiotic for the treatment of yaws. This is the first study to show that yaws—treated to date with penicillin injections—can be efficaciously treated with a single dose of azithromycin. The use of an oral treatment could pave for the way for the eradication of the disease, making yaws the second infectious disease to be wiped off the planet.
The clinical trial was conducted at the Lihir Medical Centre under the direction of Oriol Mitjà, a specialist in infectious diseases and first author of the study, and Quique Bassat, a paediatrician specialised in tropical medicine and international health, and senior author. The research was funded by International SOS and by Newcrest Mining within the Lihir Sustainable Development Plan.
"This publication is perhaps the most important on yaws in the past 50 years, and could facilitate the elimination of this ancient scourge", stated David Mabey of the London School of Hygiene & Tropical Medicine" in the comments section accompanying the article. "We have discovered an oral treatment that will broaden the therapeutic arsenal against yaws and holds much promise because of its easy administration," says Oriol Mitjà.
Yaws is a neglected tropical disease that has seen resurgence in poor communities in Africa, Asia and South America despite eradication efforts by the World Health Organization (WHO) in the 1950s. It is a chronic infection, similar to syphilis, that primarily affects the skin and bones of children and can cause severe bone deformities in the long term. It is particularly prevalent in poor rural areas in tropical countries, where conditions of overcrowding, poor hygiene and sanitation, and inadequate water supply are frequent.
Azithromycin is an antibiotic that is currently used in campaigns to eliminate other disease such as blindness due to trachoma. Its proven efficacy in the treatment of yaws could help to overcome obstacles associated with the current recommended treatment, benzathine penicillin, which requires injection equipment and trained personnel and carries the risk of allergic reactions and other side effects. "The results of this clinical trial represent a major step forward in the control of yaws as this new treatment could be easily incorporated into mass drug administration campaigns," says Quique Bassat. We have been given a second chance to eliminate yaws and to someday eradicate it completely."
The trial involved 250 children aged between 6 months and 15 years. The efficacy and safety of a single dose of azithromycin are similar to those of the conventional treatment with injectable benzathine penicillin. Both treatments achieve serological cure within 6 months and also cure the skin lesions caused by the disease.
On learning of the results of the study, the WHO convened a technical meeting at which it will probably officially recommend azithromycin for the treatment of yaws. The confirmation of the results of the study in Papua New Guinea by a similar trial already underway will probably be the first step towards the launching of a global eradication programme led by the WHO.