Yaws is an infectious disease that affects the skin and bones. It's a tropical illness that was once common in West Africa, Indonesia, New Guinea, the Solomon Islands, Haiti, Dominica, Peru, Colombia, Ecuador and parts of Brazil. In these countries, yaws most often affects children between the ages of 2 and 5, especially children who wear few clothes, have frequent skin injuries and live in areas of poor hygiene.
During the 1950s, yaws was a common tropical illness, infecting 50 million to 100 million people. Since that time, the World Health Organization (WHO) has battled yaws in many tropical areas of the world. More than 160 million people have been examined in 46 countries, and more than 50 million cases of yaws have been treated with penicillin. As a result, the incidence of yaws declined dramatically worldwide. This disease always has been extremely rare in the United States.
Yaws is caused by a subspecies of Treponema pallidum, the bacterium that causes syphilis, a sexually transmitted disease. However, yaws is not transmitted sexually. Also, unlike syphilis, yaws does not have the potential to cause long-term damage to the heart and cardiovascular system. Yaws almost always is transmitted by direct contact with infected skin.
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