What is chlamydia?

Chlamydia is a sexually transmitted infection (STI) caused by the bacterium chlamydia trachomatis. It is usually spread during unprotected sex and can affect both males and females.

Chlamydia can cause problems during pregnancy, such as preterm birth and intrauterine growth restriction (IUGR) (when your baby doesn’t grow as well as expected during pregnancy).

Chlamydia is the most common STI in Australia.

Most people with chlamydia are not aware that they have the infection. Untreated chlamydia can cause serious complications. Your baby can also be affected by the infection.

Chlamydia is usually easy to treat if you know you have it — one course of antibiotics is usually enough.

What are the symptoms of chlamydia?

Many people with chlamydia do not have any symptoms. You can carry the infection for many months or years without knowing it.

Females who do have symptoms might notice:

• a change in vaginal discharge
• vaginal bleeding between periods or after sex
• burning or pain when urinating
• abdominal or pelvic pain
• pain during sex

If you are male, you may have some clear discharge from the penis or pain during urination. These symptoms can have a range of causes other than chlamydia.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes chlamydia?

Chlamydia is caused by an infection with the bacterium chlamydia trachomatis. It is spread through unprotected sex (sex without using a condom) with an infected person.

If you have chlamydia and are pregnant, your baby can become infected during birth.

When should I see my doctor?

You should see your doctor if:

• you have any symptoms of chlamydia
• you have had sex with someone who has chlamydia, or who has a history of chlamydia
• you have had sex without using a condom and you are at a higher risk of an STI
• you are pregnant and think you may have chlamydia

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is chlamydia diagnosed?

Your doctor can diagnose chlamydia by sending a sample of your urine or a swab from your vagina, cervix, anus or throat to the laboratory for testing.

During pregnancy, you have the option of providing the vaginal swab to your doctor yourself. Ask your doctor if this is something you’re interested in.

If you are pregnant and under 30 years old, your doctor will discuss screening for chlamydia as part of your routine antenatal tests.

Read about screening tests for STIs.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is chlamydia treated?

Chlamydia is usually treated with a course of antibiotics. Sometimes, a longer course is needed. During pregnancy, chlamydia is usually treated using an oral antibiotic called azithromycin that is safe for both you and your baby.

It is important to notify anyone you have had unprotected sex with, so they can be tested and treated (if needed). If they have chlamydia, they can infect others, and also reinfect you, even if you have already been treated.

If you are worried your sexual partners will not seek treatment themselves, in some states and territories, you can get them an antibiotics prescription yourself. This is called patient delivered partner therapy (PDPT). Speak with your GP to see if you can access this program in your state or territory.

Your doctor may also recommend:

• a full STI check-up, including HIV (human immunodeficiency virus) and syphilis
• avoiding all sexual contact, even with a condom, for 7 days after starting treatment
• avoiding sex with any partners from the last 6 months until they have been tested and treated
• retesting 4 weeks after treatment in some cases, such as pregnancy
• retesting 3 months after treatment, to check for reinfection

Chlamydia is a nationally notifiable disease. This means that if your doctor diagnoses chlamydia, they are legally required to notify the Department of Health. This process is used to track cases of chlamydia to find outbreaks and improve healthcare responses. Information that identifies you as an individual, including your name, is not provided to the Department of Health.

Contact tracing

Contact tracing is when you work out who might have been exposed to you while you were infectious. It can help identify people who might be infected, so they can be tested, and can reduce the chance of you being reinfected after treatment.

Your doctor can help you decide who needs to be contacted. You can contact those who need to be informed either personally or anonymously. The website Let Them Know can help you contact partners anonymously.

What are the complications of having chlamydia during pregnancy?

If you have chlamydia during pregnancy, you are at a higher risk of your waters breaking early and leading to premature birth. Your baby is also at risk of being born with a low birth weight.

If you have chlamydia during birth, your baby can become infected, causing eye infections (conjunctivitis) and pneumonia. If your baby is infected, they may need treatment with antibiotics.

Read more about general complications of chlamydia for males and females.

Can chlamydia be prevented?

You can prevent chlamydia and other STIs by practicing safe sex and using condoms during sex.

Don’t have sex with people diagnosed with chlamydia until 7 days after they have completed their antibiotic treatment. If you are taking medicine for chlamydia but your sexual partner is not, you could be reinfected.

Read more about safe sex during pregnancy.

Resources and support

You can also visit these websites for more information:

• Read more on the NSW Health chlamydia fact sheet.
• The Sexual Health Quarters educates, informs and empowers people to enjoy good sexual health and relationship wellbeing.

Other languages

Talk. Test. Treat. has a guide with many different sexual health resources translated into different community languages.

For help in your own language, call the Telephone Interpreting Service (TIS) on 131 450 and ask the interpreter to call Sexual Health Quarters on 1800 198 205.

Aboriginal and/or Torres Strait Islander peoples

Better to know provides information about sexually transmissible infections for Aboriginal and/or Torres Strait Islander people.