Sexually transmitted disease caused by infection with the bacterium Haemophilus ducreyi. Symptoms usually appear four to seven days after exposure. This organism causes one or more ulcers or raised bumps on the genital organs. Sores are surrounded by a narrow red border which soon becomes filled with pus and eventually ruptures, leaving a painful open sore. In 50 percent of untreated cases, the chancroid bacteria infect the lymph glands in the groin. Within five to 10 days of the appearance of primary sores, the glands on one or both sides of the groin become enlarged, hard and painful. A rounded painful swelling results which may eventually rupture.