Chancroid is a painful genital ulcer caused by which organism?

• A. Chancre
• B. Gonorrhea
• C. Chancroid
• D. Genital herpes

Answer: (C)

Chancroid presents as a painful genital ulcer. The organism responsible is Haemophilus ducreyi, a gram‑negative bacterium. The term chancroid refers to the disease itself, not the organism. Other options point to different conditions: a chancre is the painless ulcer of primary syphilis caused by Treponema pallidum; gonorrhea is due to Neisseria gonorrhoeae and typically involves discharge and dysuria; genital herpes causes painful, recurrent ulcers from herpes simplex virus. So the correct concept is that the lesion is caused by Haemophilus ducreyi.