This tropical disease affects the skin and bones and the spiral bacteria that cause it are closely related to the bacteria that cause the sexually transmitted disease syphilis
Name
Yaws
Transmission
- Yaws is part of a group of chronic bacterial infections called treponematoses
- The sexually transmitted disease syphilis is also part of this group, but yaws is the most common of these infections
- It is transmitted through non-sexual skin-to-skin contact with an infected person
- It does not exist in animals, humans are the only ones that can host and spread the bacteria
Geography
- Africa, Asia, Latin America and the Pacific
- Mostly found in poor communities in warm, humid and tropical forest areas
- Currently, there are only 13 countries with the disease because of an eradication programme
Incubation Period
9 – 90 days (the average is 21 days)
Signs and Symptoms
There are four stages: primary, secondary, latent, and tertiary.
Primary
- One yellow lesion (known as the mother yaw) develops on the face, skin, hands, or feet
Secondary
- Weeks or months later, more skin lesions similar to the mother yaw develop all over the body
- These lesions may be filled with pus and can turn into ulcers which heal slowly and can reoccur
Latent
- Symptoms reduce, but an occasional lesion may occur
Tertiary
- Bone, joint, and soft tissue deformities
- Palms of the hands and soles of the feet become thickened and painful
Note: 75-80% of all cases are in children younger than 15 years
Diagnosis
Laboratory testing of blood samples is a common way to diagnose, but these tests cannot differentiate between yaws and syphilis so clinical assessment is important
Treatment
A single oral dose of the antibiotic azithromycin can cure the disease
Prognosis
Though it is treatable, yaws can persist for years as a chronic, relapsing disease just like syphilis
Prevention: What Can You Do?
- There is no vaccine
- Maintaining good personal hygiene is important to prevent the spread of the disease
Yaws In the News
Sources:
http://www.who.int/yaws/en/
http://www.who.int/mediacentre/factsheets/fs316/en/