Professor Department of Community Medicine J.N. Medical College, Aligarh Muslim University, Aligarh Sexually transmitted infections (STIs) are infections that are spread primarily through person-to-person sexual contact. Some of the most common STIs include chlamydia, gonorrhea, syphilis, and trichomoniasis. Human papillomavirus (HPV) infection is also considered an STI. STIs are a major public health problem worldwide. They can cause serious, permanent damage to a person's reproductive and other systems if not treated. Some STIs may also increase the risk of acquiring or transmitting HIV. STIs are preventable through safe sexual practices and regular screening