Venereal disease caused by the bacterium. The disorder occurs mainly in the tropics, and more in men than women, and is transmitted by sexual contact, although some researchers maintain that it can also be caused by poor hygiene. Symptoms usually occur a few days after infection, but sometimes not until weeks later. Small wounds with the appearance of round abrasions appear on the genitals and anus. Sometimes the groins, thighs and face are also affected. If untreated the wounds develop into ulcers, and the underlying tissue becomes damaged. In the long term arthritis and anaemia can set in. Diagnosis is by skin tissue tests; treatment is with antibiotics.