Yaws—a tropical bacterial disease of the skin, bones and joints—has re-emerged in rural, tropical parts of Africa, Asia, and South America. A study published Online First by The Lancet shows that a simple regimen of oral azithromycin is as effective at clearing infection as the traditional injection of penicillin, and avoids the need for injection equipment and medically trained personnel. Thus switching to this oral regimen could allow countries to finally eliminate the disease. The Article is by Dr Oriol Mitjà, Lihir Medical Center, Papua New Guinea, and colleagues.
Yaws is caused by the spirochete bacterium Treponema pallidum pertenue. Other treponemal diseases include syphilis, which can also be treated effectively with oral azithromycin. Yaws—a neglected tropical disease—is re-emerging. 40 years after a worldwide control programme almost eradicated the disease, it has reappeared in the regions above. The disease has a natural history in primary, secondary, and tertiary stages. Unless diagnosed and treated at an early stage, yaws can become a chronic, relapsing disease, and can lead to severe deforming bone lesions in the long term.
In this randomised controlled trial at Lihir Medical Center, children aged 6 months to 15 years with confirmed yaws were randomly allocated to receive either one oral dose of azithromycin or an intramuscular injection of penicillin. 124 patients received azithromycin group and 126 penicillin. Cure rates were 96% for the azithromycin group and 93% for the penicillin group, confirming that the treatments were equivalent. The number of drug-related adverse events (all mild or moderate) was similar in both treatment groups (8% in the azithromycin group vs 7% in the penicillin group).
The authors say: "With yaws re-emerging, treatment with an effective drug that can be easily administered on a large scale is the preferred method for treatment, prevention, and, eventually, elimination worldwide."
They conclude: "Our findings provide clear evidence that one high dose of oral azithromycin is non-inferior to injectable penicillin for treatment of yaws. If further studies confirm our findings*, the next step is to attempt elimination and possibly eradication of the disease in the remaining endemic countries with mass drug administration programmes under WHO's leadership."
In a linked Comment, Dr David Mabey, London School of Hygiene and Tropical Medicine, London, UK, points out that a single dose oral treatment for yaws is a major advance that should facilitate the eradication of yaws, provided resistance to azithromycin does not develop. He points out that resistance to azithromycin has emerged in Treponema pallidum, the cause of syphilis, in high-income countries and some middle-income countries, but says this "does not necessarily imply that resistance in the closely related T pallidum subsp pertenue, which causes yaws, will become prevalent in rural areas in the developing countries where yaws remains endemic".
He concludes: "More studies, such as that done by Mitjà and colleagues, are needed in other regions, and careful follow up will be needed to ensure that clinically significant resistance to azithromycin does not develop in T pallidum subsp pertenue."
Dr Oriol Mitja, Lihir Medical Center, Papua New Guinea (In Europe until Jan 12), and CRESIB (Barcelona Centre for International Health Research), Spain. T) 34-619741277 (Spain)/ 675-9867180 (PNG) E) oriolmitja@hotmail.com
Dr Russell Hays, Lihir Medical Centre, Papua New Guinea. T) 675-986-7180 / 675-764-07505 E) senior.medicalofficer@newcrest.com.au
Dr David Mabey, London School of Hygiene and Tropical Medicine, London, UK. T) 44-7743-895236 E) david.mabey@lshtm.ac.uk
Note to editors: *a similar trial is in progress in Ghana, West Africa (Kwakye-Maclean C, Ga West Municipal Heath Directorate, personal communication)
Journal
The Lancet