Chlamydia trachomatis is a gram-negative, obligate intracellular bacterium that causes the most common sexually transmissible diseases in the world. Chlamydial infection can cause cervicitis in women and urethritis in men. Most of these infections are asymptomatic but, if not treated, can lead to non-gonococcal urethritis and post-gonococcal urethritis in men. Urethritis can be complicated by acute epididymitis.
