What Is Chlamydia?

Chlamydia is one of the most common sexually transmitted infections (STIs) in the United States and worldwide. It is caused by the bacteria Chlamydia trachomatis and can infect both men and women.

Symptoms

Many people with chlamydia don't experience any symptoms at all. However, when symptoms do appear, they can vary depending on whether you're a man or a woman.

Symptoms in women:

• Unusual discharge from the vagina
• Abdominal or pelvic pain
• Fever, nausea, and irregular bleeding

Symptoms in men:

• Discharge from the penis
• Swelling and pain in the testicles

Symptoms in both men and women:

• Burning or pain when urinating
• Rectal pain, discharge, and bleeding
• Inflammation and discharge in the eyes

How Chlamydia Spreads

Chlamydia is primarily spread through unprotected vaginal, anal, or oral sex. It can also be passed from an infected mother to her baby during childbirth. Chlamydia cannot be spread through casual contact like hugging, sharing drinks, or sitting on toilet seats.

Risks and Complications

If left untreated, chlamydia can lead to serious complications, including:

• Pelvic inflammatory disease (PID) in women, which can cause infertility, ectopic pregnancy, and chronic pelvic pain
• Epididymitis (inflammation of the testicles) in men
• Increased risk of HIV transmission
• Infections in newborns, including pneumonia and conjunctivitis

Testing and Treatment

Chlamydia is most commonly diagnosed using nucleic acid amplification tests (NAATs), which are the most sensitive tests and can detect the infection from easily obtained specimens like vaginal swabs or urine. For women, vaginal swabs (clinician- or self-collected) are the optimal specimen, while urine is preferred for men. NAATs can also be used to test for rectal or pharyngeal chlamydia, though these tests are not yet FDA-cleared for those specimen types.

Chlamydia is easily treated with antibiotics, with the same treatment options for those with or without HIV. Patients are typically prescribed a single dose or a 7-day course of antibiotics, and it's important to take all of the medication as directed and avoid sex until treatment is complete and symptoms are gone, to prevent spreading the infection to partners.

Even after successful treatment, re-infection with chlamydia is common, especially for women whose partners don't receive proper treatment. Healthcare providers will often retest people about 3 months after initial treatment to check for re-infection. Infants born to mothers with chlamydia may also develop complications like conjunctivitis or pneumonia, which can be treated with antibiotics.

Telling recent sex partners about a chlamydia diagnosis is important, so they can also get tested and treated. Some providers may even give extra medication or prescriptions to partners, a practice called expedited partner therapy. The best prevention methods are consistent condom use and limiting sexual partners, though abstaining from vaginal, anal, and oral sex is the only way to completely avoid chlamydia.

References:

1. CDC. "Chlamydia - CDC Fact Sheet (Detailed)." https://www.cdc.gov/chlamydia/about/index.html
2. NHS. "Is Chlamydia Only Caught Through Sexual Contact?" https://www.nhs.uk/common-health-questions/sexual-health/is-chlamydia-only-caught-through-sexual-contact/.