Chlamydia is a sexually transmitted infection (STI) caused by the bacteria Chlamydia trachomatis. It is easily passed from person to person through sexual contact. The bacteria tend to target warm, moist areas (i.e., mucous membranes) and may infect the mouth, throat, penis, vagina, and/or rectum. It can also infect the eyes if contaminated fluid comes into contact with them.
Many people infected with chlamydia are asymptomatic, meaning they exhibit no symptoms at all. Those who do have symptoms typically experience them within 2-6 weeks of the initial infection.
If left untreated, chlamydia can lead to serious long-term health effects. Through STI screening, usually collecting a urine sample and swabs of the affected area(s), chlamydia can be effectively detected and easily treated with antibiotics.
Chlamydia bacteria was first discovered in cultures from the eye of an experimentally infected orangutan by scientists Halberstaedter and von Prowazek in 1907. They were associates of a German doctor and researcher, Albert Neisser, who discovered the gonorrhea bacteria in the late nineteenth century.
It wasn't until the 1970's that Chlamydia became recognized as a sexually transmitted infection, and by the mid-1990s, infection rates began to rise more rapidly.
Today chlamydia is the most common STI globally, second only to the human papillomavirus (HPV). Fortunately, methods for screening and treating chlamydia are simple and highly effective at curing the infection.
In Canada, chlamydia is the most commonly reported sexually transmitted infection. The average rate of reported chlamydia infection in 2018 was 363.2 per 100,000 people. Between 2009-2018, reported chlamydia infection rates in Canada increased by 40%, with 117,008 reported in 2018. Females represented 59.6% of those reported cases, although infection rates for men have been increasing faster, by almost 67.6% since 2009. This difference is mainly due to higher rates of infection among men who have sex with men.
The highest proportion of reported chlamydia cases is amongst young adults aged 15-29, representing 76% of reported cases in 2017. Although all age groups over 15 experienced an increase in reported chlamydia rates, the highest rate of chlamydia is amongst 20-24 year-olds.
Chlamydia can affect anyone; however, some populations contain a higher risk for chlamydia. Gay, bisexual, and other men who have sex with men experience higher rates of chlamydia.
Factors that can increase your risk of contracting chlamydia include:
You will know you have chlamydia because you'll show symptoms.
Most people infected with chlamydia may not show or experience any symptoms. The only way to know if you have chlamydia is to get an STI test.
You can’t transmit chlamydia once you start antibiotics.
While antibiotics are highly effective at curing chlamydia, your healthcare provider will let you know when it is safe again to resume sexual activity. This is often seven days after either (1) a single high-dose antibiotic treatment or (2) you’ve completed an entire course of 7-day oral antibiotics.
I only need to be treated for chlamydia if I test positive.
Recent sexual contacts of persons who have tested positive may also be recommended for empiric (i.e. an educated guess of potential transmission) treatment at the same time that they are getting tested as the risk of infection is high and the test might be falsely negative as the infection is relatively new.
Chlamydia will clear up on its own.
Chlamydia is a bacterial infection that will not resolve independently without treatment by a healthcare provider in the form of antibiotics. Even if chlamydia symptoms never appear or they go away, the bacteria can still be transmitted to others and cause you serious, long-term complications if not treated.
Once you've been cured of chlamydia, you can't get it again.
Chlamydia can be contracted again by someone who previously had it and has recovered from it. Transmission is possible anytime there is sexual contact with an infected individual, and reinfection is common.
Transmission of chlamydia occurs when secretions (fluid) from infected mucous membranes (i.e. throat, vagina, rectum), or semen from a person with a urethral (penile) infection, comes into contact with the mucous membranes of a non-infected person. The highest-risk behaviours in transmitting Chlamydia are penis-to-vagina (vaginal) or penis-to-anus (anal) sex. Additionally:
Preventing chlamydia along with many other STIs can include a multitude of methods, including:
If you test positive for chlamydia (or other STIs), treat it as soon as possible and notify your sexual partners so they can get tested and treated to prevent future re-infection. Abstain from sexual contact until you're re-tested and the chlamydia is gone.
Yes! The current first-line treatment to cure Chlamydia involves either macrolide or tetracycline antibiotics. Typically this consists of receiving either a single high-dose of antibiotic azithromycin or completing an entire seven-day course of antibiotics like doxycycline, usually taken twice daily.
If you cannot take those antibiotics due to allergies or another reason, your healthcare provider may prescribe alternative quinolone antibiotics taken for seven days like Levofloxacin.
If symptoms remain after initial treatment, follow up with your healthcare provider as you may require additional treatment or a different antibiotic.
Currently, there are studies underway to find a vaccine that would prevent chlamydia transmission.
