Chlamydia, caused by the bacterium Chlamydia trachomatis, can infect the throat, as well as the genital and rectal areas. This infection is one of the most frequently reported bacterial sexually transmitted infections (STIs) globally. When the bacteria infect the back of the throat, the condition is referred to as pharyngeal or oropharyngeal chlamydia.
Understanding Oropharyngeal Transmission
The infection occurs when the mucous membranes lining the pharynx come into contact with bodily fluids, such as semen or vaginal secretions, carrying Chlamydia trachomatis. The primary way this transfer occurs is through oral sexual contact with a partner who has a genital or anal chlamydia infection.
The bacteria invade cells in the mucous lining, where they reproduce and cause an infection. While the bacteria are more commonly associated with the genital and anal areas, the throat is still a receptive site for colonization. Pharyngeal chlamydia is not transmitted through non-sexual activities like kissing, sharing drinks, or casual contact.
Transmission can occur from an infected genital area to the throat, or from an infected throat to a partner’s genital area. The infection is site-specific, meaning a person can have a pharyngeal infection without a concurrent genital infection, and vice-versa.
Recognizing Symptoms and Asymptomatic Carriers
The vast majority of pharyngeal chlamydia cases do not cause any noticeable signs or symptoms. Because of this high rate of asymptomatic infection, people can unknowingly carry the bacteria for long periods and transmit it to partners. This lack of symptoms is a key reason why the infection often goes undiagnosed and untreated.
When symptoms do appear, they are usually mild and non-specific, often mimicking a common cold or strep throat. The most common symptom is a sore throat or pain when swallowing. Other indicators can include redness in the mouth or throat, swollen lymph nodes in the neck, or small white spots on the tonsils.
Symptoms, if they develop, usually appear one to three weeks after exposure occurred. Because these signs are so similar to other common illnesses, relying on the presence of symptoms is an unreliable way to determine if a pharyngeal chlamydia infection is present.
Testing, Treatment, and Prevention
Diagnosing pharyngeal chlamydia requires a specific testing method, as standard urine or cervical swab tests for genital chlamydia are insufficient to detect the bacteria in the throat. The preferred diagnostic tool is a nucleic acid amplification test (NAAT) performed on a swab taken directly from the back of the throat. This swab collects cells from the oropharynx to detect the genetic material of Chlamydia trachomatis.
If a pharyngeal chlamydia infection is confirmed, it is treated with a course of antibiotics. The first-line treatment recommended by most guidelines is a seven-day course of doxycycline, taken twice daily. Doxycycline is preferred because evidence suggests it is more effective for treating pharyngeal infections than azithromycin, which is often used for genital chlamydia.
Adherence to the full course of antibiotics is essential to ensure the infection is cured and to prevent antibiotic resistance. Treated individuals must abstain from all sexual activity, including oral sex, for seven days after completing the medication regimen. Retesting after treatment, typically three months later, is important to check for reinfection if a partner was not also treated.
The primary way to prevent pharyngeal chlamydia is to use barrier methods consistently during sexual activity. Using a condom or a dental dam during oral sex prevents direct contact between infectious fluids and the mucous membranes of the throat. Open communication with sexual partners about recent testing and sexual history is also a valuable part of prevention.