Chlamydia in the throat: risks, symptoms, protection

Chlamydia is one of the most common bacterial sexually transmitted infections (STIs), and infections in the throat are often underestimated. Chlamydia can be transmitted through oral sex—often unnoticed but with potential health consequences. How high is the risk of transmission, and what should you know to protect yourself effectively? These and other questions are answered in this blog. 

Table of Contents

• What is chlamydia?
• How is chlamydia in the throat transmitted?
• Risk factors for chlamydia infection in the throat
• What are the symptoms?
• How is chlamydia in the throat diagnosed?
• How is chlamydia in the throat treated?
• 3 important ways to protect yourself
• Summary

What is chlamydia?

Chlamydia is a sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It primarily affects the mucous membranes of the genitals, throat, rectum, and less commonly, the eyes. If left untreated, chlamydia can lead to complications such as chronic pain, inflammation, ectopic pregnancies, or infertility. In pregnant women, an infection can also increase the risk of premature birth or be passed on to the baby during delivery (WHO, 2024).

How is chlamydia in the throat transmitted?

Chlamydia in the throat is transmitted through direct contact with infectious bodily fluids or mucous membranes during unprotected oral sex. The bacteria can infect the mucous membranes of the throat (pharynx). The most common route of transmission is oral sex with a sexual partner who has a genital chlamydia infection. Transmission can occur through contact with an infected penis, vagina, or anus. Throat infections often show no symptoms but remain contagious and can unknowingly be passed on to other sexual partners (NHS, 2024).

Overview: How is chlamydia transmitted in general?

Chlamydia is primarily transmitted through direct contact with infected mucous membranes or bodily fluids. The most common routes of transmission include:

• Vaginal sex: Contact with infected mucous membranes or secretions
• Anal sex: Transmission through infectious anal secretions
• Oral sex: Contact with an infected penis, vagina, or anus
• Contact with sex toys: If not cleaned or used with protection
• Perinatal transmission (less common): From mother to child during childbirth

Everyday contact such as hugging, kissing, or sharing toilets is not a mode of transmission (Cleveland Clinic, 2023).

Risk factors for chlamydia infection in the throat

The risk of infection depends on various factors closely related to sexual behavior and the use of protection. The following increase the risk of transmission:

• Unprotected oral sex with an infected person
• No or inconsistent use of barrier methods (e.g., condoms or dental dams) during oral sex
• Sexual partner with a known chlamydia infection
• Age under 25 (higher infection risk in this age group)
• Frequently changing or recently new sexual partners
• Simultaneous infection with another STI, which can increase susceptibility to chlamydia
• Lack of regular STI testing, especially with frequent partner changes
• Lack of awareness about oral STI transmission routes and protective measures

Source: Mayo Clinic, 2024

What are the symptoms?

Chlamydia infections of the throat—as well as genital chlamydia infections—are asymptomatic or cause only mild, non-specific symptoms in about 50–90% of cases. This is particularly problematic, as affected individuals often do not notice the infection, remain untreated, and unknowingly transmit the bacteria to others. Despite the absence or mildness of symptoms, infected individuals can be contagious. Due to this inconspicuous course, chlamydia infections are often referred to as "silent" infections. When symptoms do appear, they often resemble those of a sore throat:

• Sore throat or scratchiness
• Redness or swelling in the throat
• Swollen lymph nodes in the neck
• Rare: Fever or pain when swallowing

Source: Cleveland Clinic, 2023

How is chlamydia in the throat diagnosed?

It is diagnosed using a swab from the back of the mouth and throat. A cotton swab is used to collect a sample from the mucous membranes, which is then tested for the bacterium Chlamydia trachomatis. Detection is usually done using a nucleic acid amplification test (NAAT), a highly sensitive and reliable laboratory test (CDC, 2021). These tests can be performed by general practitioners, specialists such as gynecologists, public health services, or even as self-tests.

Would you like to get tested anonymously?

With the Homed-IQ Chlamydia Test, you can test yourself discreetly and conveniently from home. The test includes a kit for a simple throat swab that you can perform yourself. You then send the sample to an ISO-certified laboratory for analysis.

Can you get chlamydia more than once?

Yes, chlamydia in the throat can occur more than once. After successful treatment, there is no immunity, and reinfection is possible if there is renewed unprotected contact with an infected person. Regular testing and the use of protective measures such as condoms or dental dams can significantly reduce the risk of reinfection.

How is chlamydia in the throat treated?

If you test positive for chlamydia, the infection is treated with antibiotics such as azithromycin or doxycycline. During treatment and until it is completed, you should avoid sexual contact to prevent further transmission. Inform current and past partners so they can get tested and treated if necessary, helping to stop the spread of the infection (CDC, 2021).

3 important ways to protect yourself:

Because chlamydia in the throat often shows no symptoms, protective measures to reduce risk are essential:

• Use condoms or dental dams: During oral sex, they provide effective protection by preventing direct contact with infectious mucous membranes or bodily fluids.
• Get tested regularly: Especially with frequent partner changes or if you belong to a risk group, regular testing is important to detect and treat infections early.
• Be open in your relationship: Honest communication about sexually transmitted infections and test results builds trust and helps reduce the risk of infection.

Source: Cleveland Clinic, 2023

Summary

Chlamydia in the throat is one of the most common sexually transmitted infections and can be transmitted through oral sex. These infections are often asymptomatic, making them harder to detect and increasing the likelihood of unknowingly passing the infection on to others. Transmission occurs through contact with infectious bodily fluids, and unprotected oral sex with an infected partner poses the greatest risk. Protective measures such as using condoms or dental dams, regular testing, and open communication about STI test results are crucial to reduce the risk of infection.