What is Chlamydia Infection - Causes, Symptoms, Diagnosis, and Treatment

What is chlamydia infection?

Chlamydia is one of the most common sexually transmitted diseases in the U.S and the UK. This infection is easily spread because it often causes no symptoms and may be unknowingly passed to sexual partners. In fact, about 75% of infections in women and 50% in men are without symptoms.


How is chlamydia infection acquired?

The infection is transmitted in 2 ways:
- From one person to another through sexual contact (oral, anal, or vaginal).
- From mother to child with passage of the child through the birth canal. Chlamydia can cause pneumonia or serious eye infections in a newborn, especially among children born to infected mothers in developing countries.


What are chlamydia symptoms?

Most people who have chlamydia don’t notice any symptoms.

If you do get signs and symptoms, these usually appear between one and three weeks after having unprotected sex with an infected person. For some people the symptoms occur many months later, or not until the infection has spread.

Chlamydia symptoms in women

Around 70-80% of women with chlamydia don't notice any symptoms. If women do get symptoms, the most common include:
- pain when urinating (peeing)
- a change in vaginal discharge
- pain in the lower abdomen
- pain and/or bleeding during sex
- bleeding after sex
- bleeding between periods
- heavier periods than usual

If left untreated, chlamydia infection will greatly threatens women's health: it can spread to the womb and cause pelvic inflammatory disease (PID). PID is a major cause of infertility, miscarriage and ectopic pregnancy (when a fertilised egg implants itself outside the womb, usually in one of the fallopian tubes).

Chlamydia symptoms in men

Around half of all men with chlamydia don't notice any symptoms. If men do get symptoms, the most common include:
- pain when urinating (peeing)
- discharge from the tip of the penis (this can be a white, cloudy or watery discharge)
- pain in the testicles

Chlamydia in the rectum, throat or eyes

Some men have mild symptoms that disappear after two or three days. Even if the symptoms disappear you will still have the infection and be able to pass it on. If chlamydia is left untreated in men they are at risk of complications such as orchitis (swollen testicles), reactive arthritis (inflammation of the joints) and infertility.

If possible complications (like PID, prostatitis, etc. ) are triggered by chlamydia infection, more symptoms would develop.

Chlamydia can infect the rectum, eyes or throat if you have unprotected anal or oral sex. If infected semen or vaginal fluid comes into contact with the eyes you can also develop conjunctivitis.
Infection in the rectum can cause discomfort, pain, bleeding or discharge. In the eyes chlamydia can cause irritation, pain, swelling and discharge the same as conjunctivitis. Infection in the throat is less common and usually causes no symptoms.


How is chlamydia infetion diagnosed?

The test for chlamydia is simple. Most people can have the test carried out on a urine sample. Some people have a swab test (a small cotton bud). The swab is used to gently wipe the area where you might have chlamydia, to collect some cells. The cells are then tested for infection.

The doctor or nurse will explain which is the best test for you to have. You don’t always have to be examined by the doctor or nurse – this will depend on your situation and where you go to get tested.
People who have had anal or oral sex might have a swab taken from their rectum or throat. This isn’t done on everyone.

If you have symptoms in your eye, such as discharge or inflammation, a swab test might be taken to collect cells from your eyelid.

Tests for women

Chlamydia tests on women can be done with a urine sample or swab test. If a woman has a swab test, it can be taken from the cervix, or inside the lower vagina. Occasionally the doctor or nurse may advise you to have a swab test from the urethra (where urine comes out). Usually you can do a lower vaginal swab yourself, although sometimes a nurse or doctor may do it.

If you have had anal or oral sex you might also be offered a swab test taken from the rectum or throat. This isn’t done on everyone.

Routine cervical screening tests (smear tests) do not detect chlamydia. You will need to tell the doctor or nurse if you would also like to be tested for chlamydia at the same time.

Tests for men

Men will usually have a chlamydia test on a urine sample. Occasionally, a swab test may be taken from the urethra (the tube where urine comes out) at the tip of the penis.

If you have had anal or oral sex you might also be offered a swab test taken from the rectum or throat. This isn’t done on everyone.


How reliable is a chlamydia test?

The accuracy of tests varies, depending on the type of test that is used. Recommended tests are 90-95% sensitive. This means that they will detect chlamydia in most people who have the infection. Some tests you can buy may be less reliable.

Remember that no test is 100% accurate. There is a small chance that a test may show negative even when you have chlamydia. This is called a false negative test result. It is also possible for a test to be positive even when you do not have chlamydia. This is called a false positive test result. Both of these false tests are very rare but can sometimes explain why you get a different result to your sexual partner.


How is chlamyda infection treated?

Chlamydia infection is often treated with antibiotics. A convenient single-dose therapy for chlamydia is 1 gm of azithromycin (Zithromax, Zmax) by mouth. Alternative treatments are often used, however, because of the high cost of this medication. The most common alternative treatment is a 100 mg oral dose of doxycycline (Vibramycin, Oracea, Adoxa, Atridox and others) twice per day for seven days. Unlike gonorrhea, there has been little, if any, resistance of chlamydia to currently used antibiotics. There are many other antibiotics that also have been effective against chlamydia. As with gonorrhea, a condom or other protective barrier prevents the spread of the infection. Latest researches show that genital chlamydia infection can be treated with appropriate herbal formulas as well.