Yaws and other endemic treponematoses

Yaws

Picture from "Yaws: Recognition booklet for communities"
Endemic treponematoses

Endemic treponematoses are a group of chronic bacterial infections caused by treponemes. These infections are:

  • Yaws, also known as framboesia or pian, caused by Treponema pallidum subsp. Pertenue;
  • Endemic syphilis, also known as bejel, caused by T. pallidum subs. Endemicum;
  • Pinta caused by T carateum.

All these infections often affect the skin and present skin lesions.

Bejel occurs principally in the Sahel region of Africa and Arabian Peninsula and pinta is restricted only to Latin America.

Yaws

Yaws is the most common of these infections, occurring mainly in poor communities in warm, humid tropical regions of Africa, Asia, Latin America and Western Pacific.

Almost 75% of people affected are children under 15 years, although peak incidence occurs in children between the ages 6–10.

Symptoms

Yaws is transmitted primarily through skin contact with an infected person. A single skin lesion develops at the point of entry of the bacterium after 2-4 weeks. If left untreated, multiple lesions appear all over the body. Although rarely fatal, yaws can lead to chronic disfigurement and disability. Overcrowding, poor personal hygiene and poor sanitation facilitate the spread of the disease.

Treatment

Two antibiotics are recommended for treatment of yaws:
1. Azithromycin: 30 mg/kg (maximum 2g) is the preferred first line treatment.
2. Benzathine penicillin: 1.2 million units (adults) and 0.6 million units (children). Benzathine penicillin is used wherever azithromycin is unavailable or when the patient cannot be treated with azithromycin.

Elimination to eradication

Experts believe that yaws can easily be controlled and possibly eradicated as the disease occurs only in humans. Past experience has showed that elimination is possible in many countries. More recently, India eliminated yaws with no new cases since 2004. The NTD roadmap Accelerating work to overcome the global impact of neglected tropical diseases – A roadmap for implementation. Executive summary [pdf 1.2Mb] has targeted yaws for eradication by 2020. If successful, it will become the first disease to be eradicated through the use of antibiotics

Yaws in the news

27 March 2014 | Geneva
WHO to investigate yaws in the Philippines decades after last recorded cases. Expert consultation notes progress in six countries where yaws is known to occur.


26 February 2014 | Geneva
Yaws eradication will need millions of donated antibiotics.
Read The Guardian article
Read the yaws updated fact sheet


Photogallery

Cases of yaws treated with single-dose oral azithromycin
See pictures

Contact

Yaws Eradication Programme:
yaws@who.int