Gonorrhoea is a common sexually transmitted disease caused by Neisseria gonorrhoeae, a gram-negative diplococcus. The primary site of infection is the mucous membranes of the urethra, endocervix, rectum, pharynx and conjunctiva.

Transmission is usually by the direct inoculation of infected secretions from one mucous membrane to the other. Transluminal spread from urethra or endocervix may occur and cause epididymo-orchitis or prostatitis in men and pelvic inflammatory disease (PID) in women. Haematogenous spread may also occur, causing skin lesions, arthralgia, arthritis and tenosynovitis (disseminated gonococcal infection).

Seven mycoplasmal strains have been isolated from the genital tract, of which Mycoplasma hominis and Mycoplasma genitalium are the commonest.

M. genitalium has an unknown incubation period, but symptoms commonly develop within one to three weeks.

There is an estimated 2–2.5-fold increase in the risk of urethritis, cervicitis, pelvic inflammatory disease, infertility and preterm delivery for women infected with M. genitalium.

It can be found in the vagina, cervix and endometrium, and usually the infections are asymptomatic. Most studies have the organism in 10–30 per cent of women with clinical cervicitis.

M. genitalium infection is a sexually transmitted infection.