Chlamydia (Chlamydia trachomatis) is a bacteria that causes a sexually transmissible infection (STI). It is spread by vaginal, anal or oral sex with someone who has the infection. It most commonly affects the urethra (the tube from the bladder that urine passes through), cervix (neck of the womb) the anus and can also occur in the throat. In women it may spread to the uterus (womb) and fallopian tubes. Chlamydia can also be transferred to the eyes through rubbing or touching with unwashed hands that have touched the genital area. This type of infection should not be confused with Trachoma which is an eye infection caused by a related type of chlamydia.

Chlamydia is the most common bacterial sexually transmissible infection world-wide, with over 20,000 notifications in Queensland in 2015. Nearly 80 per cent of people who are diagnosed with chlamydia are between the ages of 15 and 29 years and most do not have any symptoms. This means that someone with chlamydia infection may not know they have it and can pass it on to someone else through unprotected vaginal, anal or oral sex.

Signs and Symptoms: 

If symptoms do occur, they usually develop about two to 14 days after having unprotected sex with someone who has a chlamydia infection.

Women with a chlamydia infection may notice that they have:

  • a change in their vaginal discharge (more discharge or a change in colour and smell)
  • crampy pain in the lower abdomen (just above the pubic bone)
  • menstrual changes including longer, heavier periods which may be more painful
  • pain when passing urine
  • bleeding or spotting between periods or after having sex
  • pain during or after sex.

Men with a chlamydia infection may notice:

  • a discharge from the penis
  • discomfort or irritation at the tip of the penis (urethra)
  • pain when passing urine
  • swollen and sore testes if the infection goes up the urethra (the testes are where sperm are produced in the scrotum).

In men and women, chlamydia can be spread through oral sex, causing infection of the throat. Chlamydia can also be spread through anal sex, causing infection of the rectum (back passage). Sometimes this can cause pain in the rectum and discharge from the anus. Mostly, it does not cause any symptoms. These anal infections should not be confused with a more serious type of anal infection called Lympho granulum venereum (LGV), caused by a related type of chlamydia. More rarely, chlamydia can also affect the joints, resulting in joint pain, swelling and stiffness. It can also cause inflammation of the eyes or a rash.


If you have had vaginal or anal sex without using a condom (unprotected sex); and without a condom or dental dam for oral sex, you could have chlamydia. Testing for chlamydia and other sexually transmissible infections can be done by your local doctor, family planning clinic or sexual health clinic. Testing for chlamydia is simple. The doctor or nurse can test for chlamydia by:

  • taking a urine sample and sending it to the laboratory for testing (it usually takes a few days for the result to come back). This is the most common way to test for chlamydia
  • taking a swab from the vagina or cervix in women, or from the opening of the penis in men who have a discharge. It is also recommended that men who have sex with men have an anal and throat swab taken if they have had unprotected anal or oral sex (this is done with a cotton bud or similar device and does not usually hurt).

Queensland residents aged 16 years or older can order a free chlamydia and gonorrhoea urine test through 13 HEALTH webtest. This new service offers users 2 options to get tested, plus provides support and reminders to get treatment if your test is positive. As this is a new service, we are monitoring its usage as part of a research project.

If you wish to be tested for chlamydia and gonorrhoea but do not wish to participate in the 13 HEALTH webtest research project, you cannot use this service. There are other options to get tested. You can ask for STI testing at any general practice clinic, at Aboriginal Medical Services, sexual health services and some community-based testing sites.

If you have had unprotected sex, you may have chlamydia so it's best to have a sexual health check.

If people find out that they have chlamydia, anyone they have had sex with in the past six months should also be tested and may need treatment at the same time. For people who feel uncomfortable or embarrassed about telling their sexual partners; a member of the health care team may help by contacting sexual partners on their behalf. Names are not mentioned to ensure the process is confidential. Alternatively, online tools and services that assist with telling partners in a confidential and if desired, anonymous way are available:

Advising sexual partners that they have been exposed to a STI is important for their health and the health of any other people they may have had sex with.

Chlamydia can usually be effectively treated with a single dose of antibiotics. In some cases a longer course of treatment may be needed.

To ensure that chlamydia has been treated properly:

  • take the tablets as advised by your doctor, nurse or pharmacist
  • avoid sexual contact or use protection (condoms or dental dam) for any sex for the seven days after you have taken the tablets
  • avoid sexual contact or use protection with your partner/s until you have both/all taken your tablets

Anyone who has had chlamydia should have another test three months after they have been treated to make sure that they have not got chlamydia again. It is common for people to get chlamydia again from a sexual partner who has not been treated.


The best way to avoid getting chlamydia is to practise safe sex - that is to use a condom when you have vaginal or anal sex and to use a condom or dental dam for oral sex. People who have had unprotected vaginal, anal or oral sex may be at risk of chlamydia infection. The only way to know that they do not have an infection is to get a sexual health check. Practise safe sex. Always using condoms when having vaginal or anal sex is the best way to avoid getting a chlamydia infection. Using a water based lubricant with condoms is recommended. If people have more than one sexual partner and do not use condoms, they should have regular sexual health check-ups.

Health outcome: 


Without treatment, chlamydia can spread from the vagina to the cervix, uterus (womb), fallopian tubes, ovaries and other parts of the lower abdomen. This type of infection is called pelvic inflammatory disease (PID). PID is a serious illness that often causes fever and pain in the lower abdomen. Women with PID sometimes need to go to hospital for treatment. Often however, a woman can have PID without knowing it.

PID can cause the fallopian tubes to become blocked with scar tissue and this can make it difficult for a woman to become pregnant. Once blocked by scar tissue, if pregnancy does occur the fertilised egg may become lodged in the fallopian tube (known as an ectopic pregnancy) and become a serious health issue requiring hospitalisation. Such pregnancies cannot continue as a normal pregnancy, and may endanger the life of the woman.

Babies born to mothers with untreated chlamydia may develop eye or lung infections. This is why it is important for pregnant women to have antenatal checks, which should include a test for chlamydia, early in their pregnancy, and late in the pregnancy if they are at high risk (i.e. partner change or partner with someone else).

Help and assistance: 

Get qualified health advice 24/7 for the cost of a local call. 13 HEALTH (13 43 25 84)

For more information on chlamydia, people can talk to:

  • a doctor
  • a sexual health clinic
  • a True clinic.

A doctor, nurse or health worker is responsible for:

  • Providing appropriate tests, treatment and information about how to prevent STIs.
  • Helping people to ensure that their sexual partners get tested and treated.