Chlamydia

Chlamydia is a very common sexually transmissible infection (STI). It is caused by the bacterium Chlamydia trachomatis. It is often called the “silent infection” because most people who have it do not realize they are infected.

Who is at risk#

Anyone who is sexually active can get chlamydia. It is most common among young people (under 25) who change sexual partners.

Your risk is higher if you have any type of unprotected sex (without condoms) with someone who has the infection.

Signs and symptoms#

Most people with chlamydia have no signs or symptoms at all, which is why testing matters.

In the vagina and reproductive organs#

Chlamydia can infect the cervix and spread to the uterus and fallopian tubes. If left untreated, this can lead to:

• pelvic inflammatory disease (PID)
• chronic pelvic pain
• ectopic pregnancy
• infertility

During pregnancy, chlamydia can be passed to the baby during childbirth, causing lung or eye infections.

When symptoms do occur, they may include:

• unusual vaginal discharge
• a burning feeling when urinating
• pain during sex
• bleeding or spotting between periods
• bleeding after sex
• lower abdominal or pelvic pain

In the penis#

Chlamydia can infect the urethra and spread to the epididymis, the tube that carries sperm from the testicles. When symptoms occur, they may include:

• discharge from the penis
• redness at the opening of the penis (urethra)
• discomfort, stinging or burning when urinating
• sore, swollen testes

How chlamydia spreads#

Chlamydia spreads through vaginal, anal or oral sex with someone who has the infection. Because it often causes no symptoms, many people do not know they are infected.

Even if you know someone well, you cannot tell from how they look whether they have an STI. People can appear perfectly healthy and still carry chlamydia. You can catch it from a new partner or from a long-term partner who has had sex with other people.

Using condoms or dams for all types of sex reduces your chances of getting chlamydia.

Sexual health check-ups#

Sexual health check-ups are recommended for anyone who is sexually active. A check-up that includes chlamydia testing is highly recommended once a year, especially if you are under 25.

Get checked more often if you frequently change sexual partners or if you have sex without a condom, with one or more partners.

Testing and diagnosis#

Chlamydia is easily diagnosed. Tests are painless and usually involve either a urine sample or a swab from the vagina, cervix, anus or throat. The sample is sent to a laboratory, and results are usually available within about a week.

Treatment#

Chlamydia is curable, and antibiotics are very effective in treating it. If there are complications, such as pelvic inflammatory disease, a longer course of antibiotics may be needed.

To avoid passing the infection back and forth:

• Do not have sex for 7 days after you and your current partner have completed treatment.
• If your partner started treatment after you, wait until at least one week after they started.
• This applies to all kinds of sex, with or without a condom, as you can be reinfected if you have sex within those 7 days.

After you have finished treatment, have another test in 3 months’ time (or in 1 month if you had anal chlamydia) to make sure you have not been reinfected.

Reinfection is common#

Having chlamydia once does not protect you from getting it again. Even after successful treatment, you can be reinfected if you have unprotected sex with someone who has the infection.

Telling sexual partners#

If you have chlamydia, anyone you have had sex with in the last 6 months needs to be told so they can be tested and treated. If they are not treated, they could reinfect you or pass the infection to someone else.

Most people appreciate being told they may have an infection, and it is an important step in preventing further spread. Your doctor or a sexual health service can help you tell your partners that they need a test. This process is called “partner notification.”

Partner notification can be done in a way that protects your privacy, and your confidentiality is always respected. If you feel unable to speak to a partner yourself, there are confidential ways to let them know they should be tested and treated.

If you are not sure whether a partner will seek treatment, ask your doctor whether extra chlamydia medication (or a prescription) can be provided for you to give to them so they can be treated promptly. This is known as patient delivered partner therapy (PDPT). Talk to your doctor about whether it is suitable for you and your partner.

Reducing the risk#

Safer sex practices reduce the risk of passing on STIs. To lower your risk of chlamydia:

• Use condoms (external or internal) and water-based lubricant for all types of sex.
• Get checked more often if you frequently change sexual partners.
• Get tested again 3 months after treatment to check you have not been reinfected.

If you are sexually active, consider a full sexual health check that also tests for other STIs such as syphilis, HIV and gonorrhea.

Key points#

• Chlamydia is a very common STI, often called the “silent infection” because most people do not realize they have it.
• Anyone who is sexually active can get chlamydia, and it is most common in people under 25.
• Most people have no signs or symptoms, so testing is important.
• Chlamydia is easily diagnosed and is curable with antibiotics.
• Reinfection is common, so partners need testing and treatment too.

Where to get help#