Chlamydia is a bacterial sexually transmitted disease that is caused by Chlamydia trachomatis. It is a common STD that is contracted during vaginal, anal or oral sex. It can also be spread by sharing unclean sex toys. The Centers for Disease Control and Prevention (CDC) estimates that there are approximately 2.86 million chlamydia infections annually, making it the most frequently reported bacterial STD in the U.S.
Often cases of chlamydia do not show any signs or symptoms of infection. Asymptomatic cases are often spread since those infected do not realize they have it. If symptoms appear, they typically occur within 2-21 days after exposure to the STD. This is why getting tested for chlamydia is so important.
Chlamydia most frequently infects the cervix, urethra or rectum, but can also be spread to the throat during oral sex. The infection can spread to the eye if an infected area is touched and then the eye is touched. Pregnant women with chlamydia can pass the infection to their babies during childbirth. It is especially harmful to infants and can cause infections that result in blindness and even pneumonia.
Symptoms of chlamydia sometimes differ between men and women.
Symptoms in men can include:
- Discharge from the penis
- Burning/itching sensation during urination
- Pain/swelling in one or both testicles (less common)
Symptoms in women can include:
- Abnormal vaginal discharge
- Burning sensation during urination
- Pain during intercourse (less common)
- Abdominal pain (less common)
- Bleeding between periods (less common)
For both men and women, symptoms of rectal infection may include rectal pain or bleeding.
Who is at risk for chlamydia?
This STD is particularly common in young people. According to a CDC report, “chlamydia prevalence among sexually active persons aged 14-24 years is nearly three times the prevalence among those aged 25-39 years.” It is more prevalent among young women because at that age the cervix is still developing and are more susceptible to the bacteria. Women also have more surface area than men for the bacteria to infect, making it easier for the chlamydia to be contracted.
Whether symptoms are present or not, untreated chlamydia can travel to the upper genital tract and cause serious health problems. In women, chlamydia can lead to pelvic inflammatory disease (PID) and cause permanent damage leading to infertility or potentially fatal ectopic pregnancy. In men, untreated cases can lead to epididymitis, which can, but very rarely does, cause sterility.
Chlamydia can be treated and cured with antibiotics. Individuals diagnosed with chlamydia should abstain from sexual activity for one week upon finishing antibiotics. You can become infected with chlamydia again after being cured. This is why it is crucial for partners of those who have chlamydia to also get tested (and treated if found positive) for chlamydia. Chlamydia often occurs alongside gonorrhea (another bacterial STD). If you have one of these STDs, you might have the other because the risk factors are very similar. Getting tested for both is important.
Whether or not symptoms are present, testing or screening for chlamydia can be done as early as 24 hours after exposure. The incubation times varies from person-to-person; for the most accurate results, get tested two weeks after initial exposure. If you test positive for chlamydia, it is advised to get retested two weeks after completing treatment to be sure that all of the Chlamydia trachomatis bacteria is cleared from your system.
How do you test for chlamydia?
Nucleic Acid Amplification (NAA)
The three NAA tests described below, urine, swab, and DFA, work by finding the DNA of chlamydia bacteria. Because NAA tests search for the bacteria’s genetic material, it is very unlikely that a false-positive test result will occur. The incubation period for chlamydia is 1-5 days so wait five days after potential chlamydia exposure before getting tested to ensure the most accurate results possible.
Urine samples (recommended test method)
- Testing via urine samples need to consist of first-catch urine (approximately 20-30mL of the initial urine stream). Patients should not include more than the first-catch in the collection cup to avoid diluting the sample.
- Patients should not urinate for at least one hour prior to providing a sample.
- Female patients should not cleanse the labial area prior to providing the specimen.
- Endocervical swab
- Male urethral swab
- Vaginal swab
- Rectal swab
- Pharyngeal swab (throat swab) if the throat is infected
Direct Fluorescent Antibody (DFA)
- Swab cultures
- Endocervical swab
- Male urethral swab
- Rectal swab
- Neonates conjunctival swab
Why shouldn’t you get tested for chlamydia via a blood test?
A small blood sample is drawn and then tested for antibodies to Chlamydia trachomatis. Chlamydia is not a blood-borne disease or infection, but the body creates antibodies to respond to various diseases and infections, and these can be found in the blood. These tests can result in a false-positive, and cannot tell for certain that an individual has chlamydia at the time of the test, but can tell whether or not the individual has had it in the past. Since chlamydia is not a blood-borne disease, this type of test should not be used to diagnose chlamydia.
Enzyme-linked immunosorbent assay (ELISA); Antibodies, IgM
- IgM antibodies are found mainly in the blood and lymph fluid; they are the first antibody to be made by the body to fight a new infection.
- This blood sample’s results should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.
Enzyme immunoassay (EIA); Antibodies, IgG
- IgG antibodies are the most abundant type of antibody; they are found in all body fluids and protect against bacterial and viral infections.
Cell Culture and Subsequent Detection of Chlamydia by Fluorescent Antibody Test Method
- A culture allows the chlamydia bacteria to grow; but results take longer (typically 5 to 7 days) than the other tests and must be done in a lab.
- Although culture is the legal standard, it is not the gold standard for the detection of Chlamydia trachomatis.
- Women should not douche or use vaginal creams/medicines for 24 hours before having a chlamydia test.
- Test options for cell cultures include:
- Conjunctiva swab
- Cervical swab
- Rectal swab
- Posterior nasopharynx/throat swab
- Urethral swab
- Chlamydia is the most common bacterial STD in the United States.
- Chlamydia is a curable bacterial STD that doesn’t usually show signs or symptoms.
- Chlamydia can cause infertility in women and sterility in men if left untreated.
- Chlamydia can be transmitted to newborns during delivery and cause serious health complications like blindness and pneumonia.
- Chlamydia is particularly common in young people (aged 14-24) and is especially prevalent among young women.
- Co-infection of chlamydia and gonorrhea is common.
- Chlamydia can infect the genitals, rectum, throat and eyes.
- Nucleic Acid Amplification (NAA), via either urine or swab, is considered the best option in testing for chlamydia.
- Get tested for chlamydia, it is curable and easily treated.
Read Section 4 on Gonorrhea and Gonorrhea Testing