Chlamydia is a commonly acquired sexually transmitted bacterial infection (STI). It affects both men and women and is spread during sexual contact.
In 2008, there were an estimated 110 million sexually transmitted diseases (STDs) across the population of the United States. Of these, more than 1 in 5 (22.1 million) were among women and men aged 15-24.
Chlamydia is the most common STD reported to the CDC since 1994. In this article, we will discuss the symptoms, causes, diagnosis, and treatment of chlamydia.
Contents of this article:
Fast facts on chlamydia
Here are some key points about chlamydia. More detail and supporting information is in the main article.
- Chlamydia is 50 times more common than syphilis and more than three times more common than gonorrhea
- Most people with chlamydia do not exhibit symptoms
- Chlamydia has been known to cause serious and sometimes permanent damage to the reproductive system
- Chlamydia can be spread to an infant during childbirth, potentially causing an eye infection or pneumonia
- Chlamydia is a treatable infection and requires the use of prescribed antibiotics by both sexual partners
What is chlamydia?
Chlamydia is one of the most common STDs in the world.
Chlamydia is an infection by the bacteria Chlamydia trachomatis (C. trachomatis); some scientists believe it to be the most common bacterial STI in the world.
Chlamydia infection can affect several organs including the penis, vagina, cervix, urethra, anus, eye, and throat and can cause serious and sometimes permanent damage to the reproductive system.
In the U.S., chlamydial infections affect approximately 1.5 million people per year (CDC), most commonly those under 25 years old.
Causes of chlamydia
Chlamydia may be transmitted by:
- Having unprotected vaginal sex with an infected person
- Having unprotected anal sex with an infected person
- Having unprotected oral sex with an infected person
- Having genital contact with an infected person
As chlamydial infection presents no symptoms in at least 70 percent of carriers, an infected person may pass it on to their sexual partner without knowing.
Childbirth - an infected mother can pass the infection on to her baby during childbirth. Sometimes, the infection may lead to complications for the infant, such as pneumonia.
Chlamydia cannot be transmitted through:
- Contact with a toilet seat that has been used by an infected person
- Sharing a sauna with infected people
- Sharing a swimming pool with infected people
- Touching a surface that an infected person had previously touched or coughed/sneezed on
- Standing close to an infected person, inhaling the air after they have coughed or sneezed
- Sharing an office with an infected colleague
The bacterium, Chlamydophila pneumoniae, which causes respiratory infections, including pneumonia, is different from C. trachomatis, the sexually transmitted infection. Chlamydophila pneumonia is an airborne bacterium and is not a sexually transmitted infection. This article focuses entirely on C. trachomatis.
Symptoms of chlamydia
Although most people with chlamydia do not exhibit symptoms, they may start to appear 5-10 days after contracting the infection.
Chlamydia symptoms specifically affecting women may include:
- Abdominal pain
- Vaginal discharge - foul-smelling, yellow cervical discharge
- Bleeding between periods
- Low-grade fever
- Painful intercourse, bleeding after intercourse, burning with urination, swelling in vagina or around anus
- Needing to urinate more often or discomfort with urinating
Chlamydia symptoms specifically affecting men may include:1,2
- Pain and burning with urination
- Penile discharge (pus, watery or milky discharge)
- Testicle swelling and tenderness
If the rectum is affected in men or women, it can cause anal irritation. Most people, though, have no symptoms at all.
Diagnosis of chlamydia
Diagnosing chlamydia may include a physical exam to evaluate for the presence of physical symptoms such as discharge and will also include either a swab sample from the penis, cervix, urethra, throat, rectum or a urine sample.
As chlamydial infection frequently presents no symptoms, health authorities in most nations recommend screening for some people. The U.S. Centers for Disease Control and Prevention (CDC) recommend chlamydia screening for:
- Women aged below 25 years - annual screening. Women under the age of 25 who are sexually active are at the highest risk of becoming infected.
- Pregnant women - screening should be done during the first prenatal exam. Women who have had several sexual partners should have another test before the expected delivery date.
- High-risk males and females - regular screening is recommended for males and females who do not regularly use a condom, those who have multiple sex partners, and people who have another sexually transmitted disease.
How is chlamydia screening done?
Women - women can go through the procedure at home or in the lab, either with a urine sample or by taking a swab from the lower vagina. The swab is placed in a container and sent to a laboratory.
Men - a urine test is most commonly used.
Speak with your doctor about the necessary testing for your individual situation. Some people may have rectal or throat testing, especially in HIV-positive people.
Treatments for chlamydia
Treatment of chlamydia is very important because, if it is left untreated, it can cause long-term health consequences, including infertility and ectopic pregnancy.
Antibiotics are very effective in treating chlamydia if the patient sticks to the doctor's instructions. In most cases, they will be pills that the patient swallows. Repeat testing 3-4 months after treatment may be recommended, depending on risk factors.
Treatments for chlamydia may include:
- Azithromycin - the patient receives just one dose.
- Doxycycline - the patient usually takes the pills for 1 week. It is important that the course is completed to ensure the infection does not return.
Some patients, such as pregnant women, may be given alternative antibiotics. Doxycycline or tetracycline may affect the development of the baby's bones and teeth.
The following antibiotics are alternatives recommended by the CDC: erythromycin, levofloxacin, and ofloxacin. Some patients may experience side effects when they take antibiotics:
In most cases, the side effects will be mild. Patients taking doxycycline might have a skin rash if they are exposed to sunlight.
If the chlamydia is not treated, approximately 10-15 percent of women will develop pelvic inflammatory disease, known as PID.
Treatment of men is equally as important; if it is left untreated, chlamydia can lead to epididymitis and reactive arthritis.
Prevention of chlamydia
Condoms can prevent a person from contracting chlamydia during vaginal and anal sex.
In order to avoid spreading chlamydia, individuals should avoid sexual activity until treatment is complete; if a one-time dose of antibiotics is prescribed, it is recommended that people avoid sex until 7 days after treatment.
Taking some basic precautions, such as the use of condoms for vaginal and anal sex and the use of condoms or other barrier methods for oral sex, can prevent a person from contracting chlamydia.
- Condoms - significantly reduce the risk of becoming infected
- Oral sex - barrier protection can reduce risk of infection
- Regular screening - regular screening for people in high-risk groups reduces the risk of transmitting the infection and reduces complications of the disease
Complications of chlamydia
Early diagnosis and treatment greatly reduce the risk of complications. Complications can be prevented with regular screening, or by seeking medical attention as soon as symptoms appear.
Women - chlamydia complications
Pelvic Inflammatory Disease (PID) - an infection of the ovaries, fallopian tubes, and uterus, that can lead to infertility. Approximately 10-15 percent of women will develop PID if the chlamydia is untreated.
Cervicitis - inflammation of the cervix (neck of the womb). Symptoms can include a vaginal discharge that contains pus and pain during intercourse.
Salpingitis - inflammation of the fallopian tubes. If the fallopian tubes become blocked, the egg will not be able to pass along or enter the fallopian tube. There is a significantly increased risk of ectopic pregnancy.
Men - Chlamydia complications
Urethritis - the urethra, a tube which carries urine from the bladder to the end of the penis, becomes inflamed. Symptoms include a discharge with yellow pus, mucus with pus, or just clear mucus at the opening (the hole at the end of the penis where urine comes out).
Epididymitis - inflammation of the epididymis, a structure inside the scrotum (sack that holds the testicles). Signs and symptoms include red, swollen, and warm scrotum, testicle pain and tenderness which is usually on one side, painful urination, frequent urination, painful ejaculation, painful intercourse before ejaculation, lump in testicle, swollen inguinal nodes (lymph nodes in the groin), discharge from penis, and blood in the semen.
Reiter syndrome (men and women) - a chronic type of inflammatory arthritis. This can include arthritis, conjunctivitis (inflammation of the eyes), and inflammation of the genital, urinary, and gastrointestinal systems. The body's organs, as well as the joints, can become affected. Serious inflammation can affect the eyes, kidneys, heart, skin, lungs, and mouth.