Yaws is an infectious, nonvenereal, treponemal disease caused by Treponema pallidum subsp pertenue . The disease is transmitted by direct skin contact and usually affects children, with a peak incidence in those aged 6-10 years. Similar to syphilis, yaws can persist for years as a chronic, relapsing disease. Yaws continues to be endemic along the tropical belt in areas characterized by hot temperatures, high humidity, and heavy rainfall. These conditions coupled with the persistence of poverty, poor sanitation, overcrowding, and lack of public health surveillance allow for disease perpetuation.
Cutaneous lesions characterize the primary and secondary stages.
The tertiary stage may include involvement of skin, bone, or joints. Since then, however, yaws cases rebounded due to lack of public health surveillance and inadequate treatment facilities. Currently, researchers estimate that 100 million children are at risk of acquiring yaws. Unless treated, yaws can become a chronic, relapsing disease with skin, bone, and joint involvement. Neurologic and ophthalmologic involvement also may occur.