This post is the 6th in a series highlighting the WHO’s list of 17 Neglected Tropical Diseases (now technically 18 as mycetoma was added to the list at the 69th World Health Assembly in May 2016). To read the previous posts in this series click here.
Today’s post is all about the Neglected Tropical Disease yaws, part of a group of bacterial infections known as endemic treponematoses. Yaws is a chronic, disfiguring childhood skin disease caused by the bacteria Treponema pallidum subspecies pertenue. It is quite nasty and without treatment can lead to chronic disfigurement and disability.
For as nasty as yaws is, it is easily curable with one single dose of the inexpensive antibiotic azithromycin. There is no vaccine but because yaws is curable and also only transmitted between people (no animal reservoirs exist), eradication is a possibility. During the 1950s at least 88 countries within the tropical belt area of the planet were endemic for yaws, now we’re down to about 13 countries. The disease is predominantly found in poor communities where low socio-economic status coupled with poor personal hygiene (due to lack of soap and clean water) and overcrowding, contribute to the spread of yaws among kids under 15 years of age. Transmission is through direct person-to-person (non-sexual) contact of minor injuries of the uninfected person with fluid from a yaws lesion. Most lesions occur on the limbs.
So now that we know a little bit more about yaws, let’s go back to the plan to eradicate it. The WHO, in 2012, published a yaws eradication strategy outlining how to achieve eradication by 2020. As I’m sure you all know, humanity has been striving to repeat the smallpox eradication achievement. We’re getting close on guinea worm and there’s a plan in place for yaws, but as you can all imagine, eradication of any disease is not an easily achievable task. This article in the Lancet highlights the yaws-eradication challenges facing the world. But progress is being made. In May 2016, India was recognized as having officially interrupted yaws transmission in October 2015, making India the first WHO member-state to achieve this milestone. And with the discovery of a cure for yaws with one dose of azithromycin, curing yaws has become easier but full eradication will require millions of donated doses.
Yaws is one of the few diseases with a true potential for eradication given our current technology and resources. Maybe it will become the second human disease ever eradicated, and hopefully only the first of many I’ll see in my lifetime.