Chlamydia
Chlamydia (pronounced clam-id-ee-a) is a sexually transmitted infection. Officially, it is a bacterium, but it is more like a virus in being very small and unable to multiply outside living cells. Chlamydia is not life-threatening, but it can do serious damage to a woman’s Fallopian tubes. If this happens, the woman could become infertile (unable to become pregnant). The results of chlamydia infection cost the NHS in the UK about £50 million a year.
Is chlamydia common?
In the UK and USA, chlamydia is the commonest sexually transmitted infection.
- In 2007, 121,986 new cases were seen at sexual health clinics in England, Scotland and Northern Ireland. This is an 7% rise compared with 2006.
- Of those affected, 65% were in the 16–24-year age group.
- Chlamydia is not just a disease of young people; it is increasing in older age groups as well as in young people.
The true figure must be even higher than the clinic figures suggest, because chlamydia is often a ‘silent’ infection – not causing any symptoms – especially in women. There must be hundreds of thousands of people with the infection who are unaware they have it, and therefore do not go to a clinic. When doctors in Portsmouth, UK, tested urine samples from all sexually active women under the age of 25 (who were visiting their family doctor for any reason), they found about 1 in 10 had chlamydia (Sexually Transmitted Infections 2003;79:22–27).
How you get chlamydia
Chlamydia is passed on during sex, but using a condom gives good protection if you use it properly. You can also catch chlamydia during oral sex, because it can be carried in the back of the mouth. Because most people with chlamydia do not know that they have it, they can pass it on to someone else unknowingly. It is not caught from toilet seats or swimming pools.
How do you know if you have chlamydia?
- About 50% of men with chlamydia have no symptoms, and do not know that they have the infection. In the other 50%, chlamydia irritates the urethra (the tube inside the penis), causing a discharge and making it painful to pass urine. Occasionally (in about 2% of cases), chlamydia spreads to the testicle (usually only on one side), where it causes pain and inflammation; some doctors think that if this happens, the man’s fertility could be affected.
- In women, chlamydia infection is usually completely silent, so they are unaware that they have it – 80% of women with chlamydia have no symptoms at all. Some women notice a slightly increased discharge, or slight bleeding between periods or after sex. If it has reached the Fallopian tubes (see below), it can cause pain in the lower part of the abdomen (tummy).
- Some men (and a few women) develop ‘Reiter’s syndrome’. This is a reaction to the chlamydia bacterium, and consists of painful joints (usually knees or ankles) and sore eyes (conjunctivitis). It normally clears up within 6 months, but may keep recurring over several years, even if you never get chlamydia again. Whether or not you develop Reiter’s syndrome depends more on your genes than on the severity of your chlamydial infection.
Tests for chlamydia
The best way of knowing if you have chlamydia is to be tested. This can be done at a genitourinary medicine clinic or a contraception clinic or, possibly, by your family doctor. There are several types of test.
- In women, the cervix (neck of the womb) is wiped with a cotton wool bud, which is then sent to the laboratory for testing. To do this test, the doctor or nurse will insert a speculum into the vagina, like having a smear test. In men, the cotton wool bud is inserted into the end of the urethra (pee hole) to obtain the sample.
- A urine sample can be tested. However, this test is not available everywhere and, for women, it is not as reliable as taking a sample from the cervix. For this test you must hold your urine for at least an hour beforehand.
- A sample from the vagina in women can be tested using a new more accurate test (nucleic acid amplification test, NNAT). This means that women could take their own samples.
In the UK, a national Chlamydia Screening programme started in 2003. It aims to test all sexually-active women and men under 25 years of age. At present you can be screened for chlamydia at a genitourinary medicine clinic or contraception clinics and at some other places (such as colleges, military establishments). Some pharmacies offer free chlamydia tests for 16–24-year-olds.
When to have a chlamydia test
Several situations in which it would be sensible to have a chlamydia test are:
- if you have symptoms, such as discharge or lower abdominal pain (women), pain on passing urine (men) or pain in the testicles (men)
- if your partner has symptoms
- if you had sex with a new partner without a condom in the past year
- if your partner has had a chlamydia infection and you are not sure if he/she was properly treated
- if you had treatment for a chlamydia infection, but your partner did not have treatment
- if you and your partner had treatment for a chlamydia infection, but had sex before the treatment was completed
- if you have another sexually transmitted infection (such as genital warts)
- if you are about to have a termination of pregnancy (abortion).
What happens if chlamydia infection is not treated?
If you have a chlamydia infection, it may or may not give you symptoms. If you have symptoms, such as a discharge, the symptom may disappear in a few days. This does not mean that your body has cured the infection. You are probably still carrying the chlamydia bacterium and can pass it on to other people. Also, if you are a woman, it can start to travel towards your Fallopian tubes. So go for a test, even if the symptoms have gone.
Pelvic inflammatory disease. In most women who have it, chlamydia travels no further than the cervix (neck of the womb at the top if the vagina). But in about 1 in 10, it travels further upwards through the uterus (womb) into the Fallopian tubes. In the Fallopian tubes it can cause inflammation known as ‘pelvic inflammatory disease’ or PID. Other types of bacteria may then move in making the inflammation worse. PID may be painful, but can occur without any pain at all. If the infection is treated at this stage, the tube may recover completely, or some scarring and other damage may remain.
In Denmark, where many young women are screened for chlamydia, the number of women with PID has halved.
Infertility. The Fallopian tube is where the sperm meets the egg, and where fertilization occurs. So if a woman’s tubes have been damaged by PID in the past, the egg and sperm will not be able to travel along it easily, and she may not be able to conceive. If she does conceive, there is a possibility that the fertilized egg could get stuck in the tube, and the baby would start to develop in the tube instead of in the uterus. This is called ‘ectopic pregnancy’ and is a bad situation, because the developing baby almost always dies in early pregnancy, and there will be dangerous internal bleeding.
However, while it is true that chlamydia can cause infertility, this happens in only a small number of women who have it. The risk is not precisely known, but a Swedish study in the early 1990s suggests the following figures.
- If 100 women get a chlamydia infection, 20 will develop PID.
- Of these 20 who develop PID, 2 will have difficulty conceiving and 1 will have an ectopic pregnancy.
- The more times a woman has PID, the greater the damage to the tubes and the greater the chance of later problems. So if those 20 women had another attack of PID, 4 would become infertile and 2 would have ectopic pregnancies.
- If those same 20 women had three or more attacks of PID, 8 or 9 would become infertile and 4 would have ectopic pregnancies.
Untreated chlamydia is also a concern for men. There is now a lot of evidence that chlamydia infection can reduce fertility in men, possibly by damaging sperm. A study published in Fertility and Sterility in August 2008 indicates that Chlamydia infection may lower the sperm count.
Treatment for chlamydia and talking to your partner
The good news is that chlamydia is easily treated, usually with doxycycline antibiotic. This treatment is over 95% effective if you take the full course (usually twice a day for 7 days) exactly as instructed by your doctor. Other antibiotics (azithromycin, erythromycin) are sometimes used instead; if you are pregnant or breastfeeding your doctor will probably give you erythromycin.
It is essential that your partner is treated as well. If your partner is not treated at the same time as you, you can catch it again from him/her. This is a bad thing for women, because the more times a woman has a chlamydia infection, the greater her risk of later infertility. So do not have sex (even with a condom) until both of you have completed your treatment.
You may feel anxious about telling your partner about the infection. Sometimes partners do not believe they could have it themselves, because they probably have no symptoms. So explain that most people with chlamydia do not know that they have it. If you think that telling your partner would be problematic, talk to a health advisor at your local genitourinary medicine clinic.
