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Chlamydia

Topic Overview

What is chlamydia?

Chlamydia (say "kluh-MID-ee-uh") is an infection spread through sexual contact. This infection infects the urethra in men. In women, it infects the urethra and the cervix and can spread to the reproductive organs. It is one of the most common sexually transmitted infections (STIs).

Chlamydia does not cause problems if you treat it right away. But left untreated, it can lead to serious problems, especially for women:

  • If it spreads, it can cause pelvic inflammatory disease. This serious infection can make it hard or impossible for a woman to get pregnant.
  • Pregnant women who have chlamydia often pass it to their babies at birth. If the infection gets in a baby's eyes, it can cause blindness. They can also have other problems, like pneumonia. Pneumonia can be deadly in a newborn.
  • Having chlamydia makes a person more likely to get HIV from someone who is infected with HIV. HIV is the virus that causes AIDS.

What causes chlamydia?

A certain kind of bacteria causes chlamydia. It can spread from one partner to another through vaginal, anal, or oral sex. A pregnant woman can pass the infection to her newborn during delivery.

What are the symptoms?

Most people don't have symptoms. When symptoms do occur, they can include pain when you urinate, cloudy urine, or an abnormal discharge from the penis or vagina.

You can spread chlamydia even if you do not have symptoms. You are contagious until you have been treated.

How is chlamydia diagnosed?

Your doctor will ask you questions about your past health and your sexual history, such as how many partners you have. You may also have a physical examination to look for signs of infection.

Several types of tests can be used to diagnose chlamydia. Most use a sample of urine or a swab from the cervix, vagina, or urethra.

Since chlamydia can cause serious problems but may not cause symptoms, it's a good idea to get tested once a year if you are sexually active and in your mid-20s or younger. Your doctor, local health units, and sexual health centres usually offer testing.

How is it treated?

Antibiotics are used to treat chlamydia. It's important to take all of the medicine as directed. Otherwise the medicine may not work. Both sex partners need treatment to keep from passing the infection back and forth.

As soon as you find out you have chlamydia, be sure to let your sex partners know. Experts recommend that you notify everyone you've had sex with in the past 2 months. If you have not had sex in the past 2 months, contact the last person you had sex with.

Having a chlamydia infection that was cured does not protect you from getting it again. If you are treated and your sex partner is not, you probably will get it again.

Some people who have chlamydia also have other STIs, such as gonorrhea.

Finding out that you have an STI may make you feel bad about yourself or about sex. Counselling or a support group may help you feel better.

How can I prevent chlamydia?

It's easier to prevent an STI like chlamydia than it is to treat it:

  • Don't have more than one sex partner at a time. The safest sex is with one partner who has sex only with you. Every time you add a new sex partner, you are being exposed to all of the infections that all of their partners may have.
  • Use a condom every time you have sex. Latex and polyurethane condoms keep out the viruses and bacteria that cause STIs.
  • Be responsible. Don't have sex if you have symptoms of an infection or if you are being treated for an STI.
  • Wait to have sex with a new partner until both of you have been tested for STIs.

Cause

Chlamydia infection is caused by the bacterium Chlamydia trachomatis. It is spread through vaginal, anal, or oral sex with an infected partner. A pregnant woman may spread the infection to her newborn during delivery.

You can spread chlamydia even if you do not have symptoms of infection. You can spread the infection until you have been treated.

Symptoms

Most women and men with chlamydia do not have symptoms.

The time between exposure to chlamydia and the start of symptoms—the incubation period—may range from days to months. If symptoms appear, it is usually 1 to 3 weeks after sexual contact with an infected person.

Symptoms in women

  • Painful urination
  • Cloudy urine
  • Abnormal vaginal discharge
  • Abnormal vaginal bleeding with intercourse or between periods
  • Genital itching
  • Irregular menstrual bleeding
  • Lower abdominal (belly) pain
  • Fever and general tiredness
  • Swollen and painful glands at the opening of the vagina (Bartholin glands)
  • Conjunctivitis
  • Pain during sex
  • Anal discharge

Symptoms in men

  • Painful urination or itching sensation with urination (often the first symptom)
  • Cloudy urine
  • Watery or slimy discharge from the penis
  • Crusting on the tip of the penis
  • Tender anus or scrotum
  • Conjunctivitis
  • Anal discharge

What Happens

Chlamydia does not cause long-term problems if it is treated before any complications develop. Left untreated, chlamydia can lead to many complications, especially for women. If a woman has chlamydia when she gives birth, her newborn can be infected.

Having a chlamydia infection that was cured does not protect you from a future infection. A new exposure to chlamydia will reinfect you, even if you were treated and cured.

Having chlamydia increases your risk of becoming infected with human immunodeficiency virus (HIV) if you are exposed to the virus.footnote 1

Untreated chlamydia can cause a variety of complications.

Complications in women

Complications in pregnant women

Complications in newborns

  • Premature delivery. A premature infant has an increased risk of health problems.
  • Inflammation of the surface of the eyes and the lining of the eyelids (conjunctivitis). About one-half of newborns who have chlamydia get conjunctivitis.
  • Infection of the nose and throat
  • Lung infections, such as pneumonia
  • Ear infection (otitis media)
  • Urethritis, though this is very rare in infants

Complications in men

  • Urethritis
  • Inflammation of the tubes that hold sperm (epididymitis)
  • Inflammation of the prostate, the gland that makes most of the fluid in semen (prostatitis)
  • Infertility

Other complications of untreated chlamydia in all people

  • Conjunctivitis, spread by touching the infected area and then touching the hand to the eye
  • Inflammation of the mucous membrane of the rectum (proctitis), if the chlamydia is from anal sex
  • Varied symptoms, such as joint and eye inflammation, caused by bacterial infection (reactive arthritis)
  • Lymphogranuloma venereum, or LGV. This is caused by a type of chlamydia that is usually rare in Canada and the United States, but it is becoming more common in men who have sex with men. It causes open sores in the genital area, headache, fever, fatigue, and swelling of the lymph nodes in the groin. It also causes proctitis in people who get chlamydia through anal sex.

What Increases Your Risk

Risk factors for getting chlamydia include:

  • Having unprotected sex (not using condoms).
  • Having more than one sex partner.
  • Having a high-risk partner or partners. This includes people who have more than one sex partner or sex partners who have chlamydia.
  • Starting sexual activity before age 18.

Any child with chlamydia needs to be seen by a doctor to determine the cause and to assess for possible sexual abuse. For more information, see the topic Child Abuse and Neglect.

When should you call your doctor?

In women:

Call your doctor now or seek immediate medical care if you have these chlamydia symptoms:

  • Sudden, severe pain in the lower abdomen
  • Lower abdominal pain with vaginal bleeding or discharge and a fever of 38°C (100.4°F) or higher
  • Urinary burning, frequent urination, or inability to urinate and a fever of 38°C (100.4°F) or higher

Call your doctor if you have these symptoms:

  • Vaginal discharge that becomes yellowish, thicker, or bad-smelling
  • Bleeding between periods that occurs more than once when periods are usually regular
  • Pain during sexual intercourse
  • Bleeding after sexual intercourse or douching
  • Sores, bumps, rashes, blisters, or warts on or around the genital or anal areas
  • Burning, pain, or itching with urination or frequent urination lasting longer than 24 hours
  • Pelvic or lower abdominal pain without a known cause, such as diarrhea or menstrual cramps

Also call if you think you may have been exposed to a sexually transmitted infection (STI).

In men:

Call your doctor now or seek immediate medical care if you have these chlamydia symptoms:

  • Discharge from the penis and a fever of 38°C (100.4°F) or higher
  • Urinary burning, frequent urination, or inability to urinate and a fever of 38°C (100.4°F) or higher
  • Pain, swelling, or tenderness in the scrotum and a fever of 38°C (100.4°F) or higher

Call your doctor if you have these symptoms:

  • Sores, bumps, rashes, blisters, or warts on or around the genital or anal areas
  • Burning, pain, or itching with urination or frequent urination lasting longer than 24 hours
  • Abnormal discharge from the penis

Also call if you think you may have been exposed to a sexually transmitted infection (STI).

Watchful waiting

Watchful waiting is a period of time during which you and your doctor observe your symptoms or condition without using medical treatment. Watchful waiting is not appropriate for a chlamydia infection. Chlamydia causes no long-term problems if it is treated before any complications develop. But untreated chlamydia can lead to many complications. Avoid sexual contact until you have been examined by your doctor.

If you know you have been exposed to chlamydia, you and your sex partner (or partners) need to be treated. You need to be treated even if you don't have symptoms. Notify all partners with whom you had sex in the 60 days since your symptoms or diagnosis. If you have not had sex in the last 60 days, contact your last sex partner.

Who to see

Your family doctor or general practitioner can diagnose chlamydia. You may be referred to a specialist, such as a gynecologist.

Diagnosis and treatment of chlamydia are usually available at local health units and sexual health centres.

Some people are not comfortable seeing their usual doctor for an STI. Most areas have confidential clinics for diagnosing and treating chlamydia and other STIs. But for your future care it would be good for your doctor to know of this infection.

Examinations and Tests

A doctor diagnoses chlamydia using a medical history, a physical examination, and tests. During the medical history, your doctor may ask you questions such as:

  • Do you think you were exposed to any sexually transmitted infections (STIs)? How do you know? Did your partner tell you?
  • What are your symptoms?
    • Do you have discharge?
    • Do you have sores in the genital area or anywhere else on your body?
    • Do you have any urinary symptoms, including frequent urination, burning or stinging with urination, or urinating in small amounts?
    • Do you have any abdominal or pelvic pain or cramping during intercourse?
    • Do you have bleeding between your periods or after intercourse?
  • What method of birth control do you use? Do you use condoms to protect against STIs?
  • Which high-risk sexual behaviours do you or your partner engage in? For example, do you have multiple sex partners or have sex without using a condom (except if you're in a long-term relationship)?
  • Have you had an STI in the past? How was it treated?

After the medical history is taken:

Several types of tests can be used to diagnose a chlamydia infection. Test results are usually done in 2 to 3 days, except for the chlamydia culture. It can take 5 to 7 days.

Other infections can occur along with a chlamydia infection. Your doctor may recommend testing for:

Early detection

The Public Health Agency of Canada (PHAC) recommends chlamydia screening for all sexually active women age 25 and younger. The PHAC also recommends screening for women and men with high-risk sexual behaviours. High-risk sexual behaviours include having multiple sex partners or having sex without using a condom (except if you're in a long-term relationship). The PHAC does not province how often to be screened. After reviewing all of the research, the PHAC says it is wise to screen all sexually active males under age 25 until more research is available.footnote 2

You may have a urine test for chlamydia (if it is available in your area) even if you do not have a full pelvic or genital examination.

The PHAC recommends tests for pregnant women with high-risk sexual behaviours so they do not spread chlamydia to their babies. All pregnant women should be screened during their first prenatal visit. If a pregnant woman is at high risk for chlamydia, she may be tested again during her third trimester.footnote 2

The PHAC also recommends you have the test again 6 months after you finish treatment. Women who have been diagnosed and treated for chlamydia may get it again if they have sex with the same partner or partners.footnote 2

Treatment Overview

Chlamydia can be cured with antibiotics. The infection does not cause long-term problems if it is treated early. But untreated chlamydia can lead to many complications.

Treatment is recommended for:

  • People who have positive chlamydia tests.
  • Sex partners within the last 60 days of people diagnosed with chlamydia—even if they do not have symptoms.
  • Newborns of women who have chlamydia at the time of delivery.

It is important to not have sex for 7 days after the start of treatment for chlamydia.

If you are treated for chlamydia and your sex partner is not, you will probably become infected again. Encourage your partner to get treated. Use condoms to lower the chance of reinfection.

What to think about

Some people who have chlamydia may also have gonorrhea. In that case, treatment includes antibiotics that kill both chlamydia and gonorrhea. For more information, see the topic Gonorrhea.

Reinfection can occur. Symptoms that continue after treatment are probably caused by another chlamydia infection rather than treatment failure. To prevent reinfection, sex partners need to be evaluated and treated.

Repeated chlamydia infections increase the risk for pelvic inflammatory disease (PID). Even one infection can lead to PID without proper treatment. Make sure to take your antibiotics exactly as prescribed. Take the full course of medicine, even if you feel better in a couple of days.

Some doctors recommend retesting 6 months after treatment to reduce the risk of complications from reinfection.footnote 3

If you have chlamydia, your doctor will send a report to the provincial or territorial health unit. Your personal information is kept confidential. The health unit may contact you about telling your sex partner or partners that they may need treatment.

Prevention

You can reduce your risk of becoming infected with chlamydia or another sexually transmitted infection (STI) and spreading the infection.

Practice safer sex

Preventing an STI is easier than treating an infection after it occurs.

  • Talk with your partner about STIs before beginning a sexual relationship. Find out whether he or she is at risk for an STI. Remember that it is possible to be infected with an STI and not know it. HIV, for example, may not be found in the blood for up to 6 months after initial infection.
  • Be careful.
    • Avoid sexual contact if you have symptoms of an STI or are being treated for an STI.
    • Avoid sexual contact with anyone who has symptoms of an STI or who may have been exposed to an STI.
  • Do not have more than one sex partner at a time. Your risk for an STI increases if you have more than one sex partner.

For more information, see the topic Safer Sex.

Male condom use

Condoms reduce the risk of becoming infected with an STI. A condom must be put on before any sexual contact begins. Use condoms with a new partner until you are certain he or she does not have an STI.

Female condom use

Even if you are using another birth control method, you may want to use condoms to reduce your risk of getting an STI. Female condoms are available for women whose partners do not have or will not use a male condom.

Home Treatment

There is no home treatment for chlamydia. Antibiotics, taken exactly as prescribed, normally cure chlamydia infections. Chlamydia does not cause long-term problems if it is treated before complications develop. Untreated chlamydia can lead to many complications.

Finding out that you have chlamydia may cause you to have negative thoughts or feelings about yourself or about sex. You may feel embarrassed, be angry at the person who infected you, or feel frustrated with treatment. You may want to seek Counselling or join a support group for people who have sexually transmitted infections (STIs). You may get counselling from a psychologist, a social worker, or another counsellor. STI health clinics may offer Counselling and support groups.

Medications

Antibiotic treatment, when taken exactly as directed, normally cures chlamydia infections. If antibiotics are not taken properly, the infection will not be cured. Prompt treatment prevents the spread of the infection and reduces the risk of complications, such as pelvic inflammatory disease (PID).

Avoid sexual contact or use condoms until you and your partner have finished the full course of medicine.

What to think about

Call your doctor if symptoms continue or new symptoms develop 3 to 4 weeks after treatment. To prevent reinfection, your sex partners need to be tested and treated.

Some types of chlamydia can't be treated by (are resistant to) certain antibiotics. If your doctor finds that your chlamydia is resistant to the drug you are taking, you will be tested so that your doctor can prescribe another antibiotic to cure the infection.

Treatment in a hospital with intravenous (IV) medicines may be needed for women who have pelvic inflammatory disease (PID) and men who have epididymitis. In many cases, these conditions can be treated outside of the hospital with oral antibiotics and close follow-up by your doctor.

Surgery

Untreated chlamydia can cause complications, such as an abscess. Surgery may be used to drain or remove the abscess.

References

Citations

  1. Centers for Disease Control and Prevention (2017). Chlamydia—CDC fact sheet. Available online: http://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm.
  2. Public Health Agency of Canada (2008, updated 2010). Chlamydial infections. In Canadian Guidelines on Sexually Transmitted Infections. Available online: http://www.phac-aspc.gc.ca/std-mts/sti-its/cgsti-ldcits/index-eng.php. Accessed October 23, 2014.
  3. Centers for Disease Control and Prevention (2010). Chlamydial infections section of Sexually transmitted diseases treatment guidelines, 2010. MMWR, 59(RR-12): 44–49. Also available online: http://www.cdc.gov/std/treatment/2010/default.htm.

Other Works Consulted

  • American Academy of Pediatrics (2015). Chlamydia trachomatis. In DW Kimberlin et al., eds., Red Book: 2015 Report of the Committee on Infectious Diseases, 30th ed., pp. 288–293. Elk Grove Village, IL: American Academy of Pediatrics.
  • Horner P (2010). Chlamydia (uncomplicated, genital), search date September 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
  • U.S. Preventive Services Task Force (2008). Behavioral Counseling to Prevent Sexually Transmitted Infections: Recommendation Statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf08/sti/stirs.htm.

Credits

Current as of: November 17, 2021

Author: Healthwise Staff
Medical Review:
Sarah Marshall MD - Family Medicine
Thomas M. Bailey MD - Family Medicine
Adam Husney MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Devika Singh MD, MPH - Infectious Disease