What is chlamydia?
Chlamydia is a curable sexually transmitted infection caused by the bacterium, Chlamydia trachomatis. It is the most common curable bacterial sexually transmitted infection in the western world and the numbers affected are likely to be underestimated as at least 70% of women and 50% of men who are infected may be asymptomatic. Clinical signs of infection include mucosal inflammation of the urogenital tract, throat and rectum in males and females, and eye infection and pneumonia in babies born to infected mothers. Serious complications can occur if infections are not treated.

How do people get chlamydia?
Chlamydia can be transmitted during unprotected vaginal, anal or oral sex with an infected person. Contamination of the hands with genital discharge may lead to a conjunctival infection following contact with the eyes. Chlamydia can also be transmitted from an infected mother to her baby during vaginal childbirth. In such instances the baby may develop an eye infection within a week of birth and is at risk of subsequently developing pneumonia.

What are the symptoms of chlamydia?
Symptoms may be mild or absent in at least 70% of women and 50% of men. Even if a person is asymptomatic they can still transmit the infection to a sexual partner. If present, symptoms in women include; vaginal discharge, abdominal pain, bleeding between periods or after sexual intercourse and a burning sensation during urination. Men may experience discharge from the penis, burning and itching in the genital area, and pain when passing urine. If the infection is transmitted via anal sex, it can cause rectal pain, bleeding or discharge. Chlamydia transmitted via oral sex is usually asymptomatic but redness and soreness in the mouth or throat can occur. If symptoms do occur, they usually appear within 1-3 weeks of infection. They can persist or they may only last for a few days.

What complications can result if chlamydia is not treated?
In women, if chlamydia is not treated it can spread into the uterus or fallopian tubes and cause pelvic inflammatory disease (PID). This occurs in about 40% of women with untreated infections. PID may be asymptomatic or symptoms may include abdominal pain, bleeding between periods, vomiting and/or fever. Permanent damage may result and PID can cause ectopic pregnancies, chronic pelvic pain and tubal-factor infertility. In men, complications are rare but untreated chlamydia infection can cause epidydimitis, an inflammation of the male reproductive tubes, which can occasionally lead to sterility. Chlamydia is also a common cause of urethritis (inflammation of urethra).

How is chlamydia diagnosed?
Chlamydia is diagnosed by laboratory testing of urine samples or fluid from the vagina or penis, for the causative bacteria. Testing may be done at genitourinary medicine (GUM) clinics and antenatal clinics. However, GPs, family planning clinics, and health centres also offer testing. Some countries have programmes which offer screening to asymptomatic individuals in different healthcare settings.

How is chlamydia treated?
Uncomplicated chlamydial infection can be treated and cured with antibiotics. Sex should be avoided until treatment is completed and recent sexual contacts (within the last three months) of an infected person should also be tested regardless of whether they are symptomatic. However, antibiotics will not repair any permanent damage already done by the disease and further sexual contact with an infected person can result in reinfection.

How do you protect yourself against chlamydia?

  • Abstinence
  • Mutually monogamous relationship with an uninfected person.
  • Correct use of male latex condoms can reduce the risk of transmission of chlamydia.
  • Reducing the numbers of sexual partners and the frequency of new partners will reduce the risk of infection.
  • Regular testing is recommended for individuals who are sexually active and have risk factors for chlamydia (unprotected sex with multiple partners or new partners).
  • Early detection and treatment of asymptomatic infection is vital to reduce the risk of complications.

Last updated: 6 May 2008