[Prevalence of trachoma in the world].

Trachoma is known as a chronic, epidemic and blindness eye disease, which is caused by Chlamydia trachomatis. The infection and transmission of trachoma have great relationship with environment, family and sanitation. Recently, there were reports continuously about the epidemic of trachoma in some countries and districts. So, it is still a remarkable problem to prevent and therapy trachoma in the world. The prevalence, risk factors, diagnosis, preventive and therapy of trachoma are summarized in the paper.