ABSTRACT
This chapter covers the more common sexually transmitted infections (STIs), and outlines their symptoms, how they are transmitted and the treatment available. STIs can be transmitted by penetrative sex, oral sex and digitally. Anogenital warts are the commonest viral STI diagnosed at genitourinary medicine clinics. It usually takes 1 to 3 months from the time of infection for warts to appear. Genital chlamydial infection is an important reproductive health problem, because 10–30% of infected women develop pelvic inflammatory disease (PID), which if left untreated can cause fertility problems and chronic pain. Sexual intercourse can alter the pH of the vagina, which thrush and bacterial vaginosis may then colonise. Sexual activity can introduce bacteria to the urethra in both men and women, causing cystitis. Episodes of cystitis are often associated with the onset of sexual intercourse, and women who have regular intercourse have three to four times as many episodes of infection per year as women who are not having intercourse.
