A Sexually transmitted infection (STI) is any infection that is characteristically transmitted by sexual contact. A person can have an STI without having obvious symptoms of a disease. In the opinion of the WHO, STI's have a profound impact on sexual and reproductive health worldwide.
More than 1 million STI's are acquired every day. Each year, there are estimated 131 million new infections with chlamydia and more than 500 million people are living with genital HSV (herpes) infection.
STI's can have serious consequences beyond the immediate impact of the infection itself.