Yaws

**Semantic type:** Disease or Syndrome

**Definition:** An endemic, infectious, nonvenereal disease in humans that presents mainly in children younger than 15 years. The disease occurs primarily in warm, humid, tropical areas of Africa, Asia, South America, and Oceania, among poor rural populations where conditions of overcrowding and poor sanitation prevail. Infection with Treponema pertenue, a subspecies of Treponema pallidum, causes the disease.