Chlamydia is a sexually transmitted disease (STD) caused by infection with the Chlamydia trachomatis bacterium.
C. trachomatis initially infects the mucous membranes of the cervix in females and sometimes the urethra. Sometimes the infection can also spread to the uterus and fallopian tubes.
C. trachomatis infects the urethra in males.
C. trachomatis can also infect the mucous membranes of the mouth, eyes, and rectum.