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

Photo Credits: CDC, MSF

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

• WHO declares India free of yaws

Sources:
http://www.who.int/yaws/en/
http://www.who.int/mediacentre/factsheets/fs316/en/