Chlamydia is the most commonly reported bacterial sexually transmitted infection (STI) in Canada, affecting youths and young adults most often, with young women (15 to 24 years) having the most reported cases.
The infection is named after the bacterium that causes it, Chlamydia trachomatis. Most women and many men who are infected with the bacteria have no symptoms and therefore don't know they have chlamydia.
Chlamydia is easily treated, but it can sometimes lead to serious complications if it isn't caught early enough. It is estimated that up to 40% of untreated women will develop symptomatic pelvic inflammatory disease (PID), which can be very painful. The risk of preterm delivery, ectopic pregnancy, or infertility also increases with an untreated chlamydia infection.
Screening for chlamydia is routine for women who are under 25 years old, have a history of a prior sexually transmitted infection, engage in high-risk sexual behavior, or are pregnant. Men are not routinely screened for chlamydia unless they have sex with men or live in an area where there are many cases of chlamydia.