Osteoporosis

Yaws disease (yaws) is a chronic contact infectious disease caused by Treponema pallidum. This disease is a tropical infectious disease. The clinical manifestations are similar to those of syphilis, but they are not attributed to disease and are not hereditary. It does not invade important viscera and central nervous system, and it mainly involves skin. It may invade bone in later stage. It is more common in young people and children. The disease is prevalent in tropical regions such as Central Africa, South Asia, and South America. A small number of cases have occurred in the southern region of China, but they have basically disappeared.