how many sti are there?
Each year, there are an estimated 376 million new infections with 1 of 4 STIs: chlamydia, gonorrhoea, syphilis and trichomoniasis (1, 2). More than 500 million people are estimated to have genital infection with herpes simplex virus (HSV) (3). More than 290 million women have a human papillomavirus (HPV) infection (4).