Chlamydia — Symptoms, Risks, and Testing

Chlamydia is the most frequently reported sexually transmitted infection (STI) in the United States, with more than 1.6 million chlamydia cases reported in 2023. Caused by the bacterium Chlamydia trachomatis, this common infection can affect both men and women of all ages, though it disproportionately impacts younger adults.

What makes chlamydia particularly concerning is that chlamydial infections commonly show no symptoms in men and women. Data from community screening sites revealed that up to 77% of chlamydial infections were asymptomatic. Because chlamydia often doesn't cause symptoms, many people who have chlamydia don't know it and unknowingly infect other people. Despite the lack of obvious signs, left untreated, chlamydia can lead to serious complications and cause permanent damage to reproductive organs, making it difficult or impossible to get pregnant later.

Chlamydia infections spread through sexual contact, when vaginal fluid or semen containing the bacteria that causes chlamydia travels from one person to another. Sexually active people can get chlamydia through vaginal, anal, or oral sex without a condom with a partner who has the infection. Infections can also occur when sharing sex toys with an infected partner.

Several factors may increase the risk of chlamydia infection, including being under 25 years of age, having new or multiple sexual partners, inconsistent condom use, and a history of chlamydial or other sexually transmitted infections. Because the cervixes of teenage girls and young women are not fully matured, they are at particularly high risk of infection if sexually active. Higher transmission rates among certain communities are often related to networks and limited access to STI prevention resources, including sex education and barrier protection like condoms.

Because most chlamydia cases are asymptomatic, it's important to get screened for chlamydia even if you don't notice any signs of infection. The CDC recommends that sexually active women under 25 get tested annually, and women 25 and older with risk factors such as new or multiple sex partners should also receive regular screening.

Men who have sex with men should get tested for chlamydia every year, with more frequent screening recommended for those with multiple partners. Anyone with symptoms of chlamydia or a partner who has been diagnosed with an STI should get tested promptly. Since repeat infection with chlamydia is common, retesting about three months after treatment is recommended, even if partners receive treatment.

Nucleic acid amplification tests (NAAT) are considered the gold standard for diagnosing chlamydia, with samples commonly collected from urine or swab specimens from genital, anal, or throat sites depending on sexual practices. A positive result indicates an active chlamydia infection that requires antibiotic treatment. Since chlamydia and gonorrhea infections often occur together, positive results for one infection may prompt testing or treatment for the other.

A negative result generally means no chlamydia infection was detected at the time of testing. However, it's important to remember that there may be a window period between infection and when the test can detect the bacteria. If someone has chlamydia, they'll be tested again three months after finishing treatment, as reinfection is common. Self-collection of samples is recommended as the test results are similar to those collected by a healthcare provider, making testing more accessible and convenient.

The most reliable way to prevent chlamydia is to abstain from sexual contact or maintain a long-term mutually monogamous relationship with a partner who has been tested and confirmed uninfected. For sexually active individuals, latex condoms when used consistently and correctly can significantly reduce the risk of chlamydia transmission.

Access to comprehensive sex education and barrier protection methods like condoms can help prevent the spread of chlamydia within communities. The positive news is that chlamydia is easily treated and cured with antibiotics, and early treatment prevents long-term complications. Taking all prescribed medication as directed is crucial to ensure the infection is completely eliminated and to reduce the likelihood of developing complications.