Chlamydia

What is chlamydia?

Chlamydia is a sexually transmitted infection (STI) caused by the bacterium chlamydia trachomatis. It can pass from one person to another through coming into contact with infected semen or vaginal fluid, usually by having unprotected sex.

There are a few different ways in which you can contract chlamydia, the most common being unprotected vaginal, anal or oral sex. But something as simple as contact between your genitals and your partner’s can lead to transmission, even if there’s no ejaculation, orgasm or penetrative sex.

You can get it from infected vaginal fluid or from semen getting into your eye too. Chlamydia can also be transmitted through sharing sex toys that haven’t been washed properly, or that are covered by a condom that has already been used by someone who’s infected.

Who gets chlamydia?

Anyone who is sexually active can contract chlamydia. But your risk of getting it increases by having unprotected sex with someone who’s already infected. You may have chlamydia without realizing as not everyone gets symptoms, so having unprotected sex is always a risk. You can also pass the infection on to your baby if you’re pregnant, so you should be extra careful and use birth control like a condom.

You can’t get chlamydia from toilet seats, sharing baths, swimming pools, sharing cutlery, kissing or hugging.

How common is chlamydia?

Chlamydia is one of the most common STIs; the World Health Organisation estimated that in 2020, there were 128.5 million new cases of chlamydia in 15-49 year olds across the world.^[1] It’s reported more often in women than it is in men, with WHO also estimating that prevalence was 4% for women and 2.5% for men in the same year.^[2] In 2022, a report by the European Council for Disease Control and Prevention found that there were 103,119 cases reported in men, compared with 112,831 in women.^[2]

But the figures could be even higher since a lot of the time people experience no symptoms and can be unaware of the infection.

Chlamydia is usually easy to manage and treat if it’s detected early, but it can become a serious problem if it’s not addressed. So it’s important to get tested regularly for STIs if you’re sexually active to make sure that you get treatment promptly should a problem arise. If there’s any possibility that you’ve been exposed to chlamydia, you should get tested.

What causes chlamydia?

Chlamydia is caused by a bacterium called chlamydia trachomatis. This bacteria transfers from one person to another through unprotected sex or contact with infected vaginal fluids or semen. So you can contract chlamydia even if there’s no penetrative sex. The infection spreads inside the body when the infected cells multiply.

The infection isn’t limited to the genital area. Women can get chlamydia in the cervix, rectum, or throat, and men can get it in the urethra (inside of the penis), rectum, or throat. And if you’ve had chlamydia in the past and received treatment for it, you can still get re-infected should you have unprotected sex with someone who has it. There’s also the possibility of transmitting the infection to your baby during childbirth.

What are the symptoms of chlamydia?

Chlamydia can be a silent condition, meaning that you can be a carrier of the infection without showing or feeling any symptoms. This happens in many cases, so there’s a chance that you may have unprotected sex with someone who carries chlamydia without them being aware of it. So the safest route is to wear a condom and get regularly tested.

If you do get chlamydia symptoms, they will usually appear anywhere between one and three weeks after having unprotected sex or contact with genital fluids with someone who’s infected. But it may also take months for you to develop any symptoms.

Sometimes symptoms may clear up after a couple of days, but that doesn’t mean that the bacteria are gone from your system. You can still have chlamydia and pass it on to sexual partners unless you get treatment.

At least 70% of women carrying the chlamydia bacteria don’t have any symptoms or they’re so subtle that the carrier doesn’t notice them. If you do get symptoms, they may include:

• pain when you urinate
• abdominal pain that could be mistaken for menstrual cramps
• pain during or after sex
• unusual vaginal discharge (this can be a strange smell, consistency, or color)
• bleeding right after sex, or during
• bleeding between periods, whether it’s heavy or light spotting

At least 50% of men with chlamydia have no clear symptoms. But if they do get symptoms, they might include:

• pain when you urinate
• white, cloudy, or watery discharge from the tip of your penis
  testicular pain
• a burning sensation or itching in the urethra

If you experience any of these symptoms but haven’t had unprotected sex in a while, it’s better to get tested anyway because you might have been carrying the infection and only just became symptomatic.

Can chlamydia lead to other problems?

Yes. Although chlamydia is easy to treat when it’s diagnosed early on, if you don’t get help as soon as possible it can lead to complications.

For women, untreated chlamydia can spread to the womb and cause pelvic inflammatory disease, a very serious condition that can lead to lifelong infertility or ectopic pregnancies.^[1]

In men, chlamydia can cause serious swelling in the testicles and in the epididymis (the tubes that carry sperm from the testicles) and this can have a long term impact on fertility.

If you have unprotected anal sex, chlamydia can also infect the rectum and cause general discomfort, itching, a burning sensation, and rectal discharge. It can also affect the throat if you have unprotected oral sex, and the eyes if any infected semen or vaginal fluid comes into contact with them.