Chlamydia is a bacterial infection that’s easily cured with antibiotic medicine. It’s one of the most common STDs, and most people who have chlamydia don’t show any symptoms. Chlamydia is spread through vaginal, anal, and oral sex. The infection is carried in semen (cum), pre-cum, and vaginal fluids. Chlamydia can infect the penis, vagina, cervix, anus, urethra, eyes, and throat.