Chlamydia in Gay Men

Sexually transmitted infections (STIs) are infections that are transmitted from one person to another through physical contact, usually sexual. However, several of the bacteria, viruses, and parasites that we will see in this guide can also be transmitted through other channels that are not only sexual: use of injection material, food, and drink, during pregnancy or childbirth.

Infection caused by C. trachomatis is the most frequent cause of STI that can be treated in humans. The WHO estimated that in the year 20017 there were about 115 million new cases worldwide, of which about 65 million occurred in men. In addition, there was an increase in the incidence of infection by 4.1% with respect to 2016. In countries such as the United States and the United Kingdom, 6.5 million cases are reported annually. The direct and indirect costs generated by the infection with this microorganism are very high due to the consequences and sequelae generated, mainly, pelvic inflammatory disease in women and lymphogranuloma venereum (LGV) in men.

Chlamydia trachomatis is an intracellular bacterium that has many factors that contribute to its virulence, paying close attention to the components of the cell surface that allows interaction with sialic acid receptors in target tissues and the presence of a virulence plasmid. Chlamydia trachomatis is classified by the major outer membrane protein (MOMP) in different serotypes, among which L1, L2, L2a, L2b, and L3 affect men who have sex with men being the causative agent of LGV.

The infection caused by Chlamydia trachomatis can affect the urethra (penis), the anus (rectum), the throat and also the conjunctiva of the eye. This STI is very common among young people under 25 and has many clinical similarities with gonorrhea. Chlamydia is transmitted during sexual intercourse during penetration and oral sex. Anal games such as fingering and fisting also carry risk, as well as touching an infected penis or anus and then touching your own penis, anus or eyes, although this last route of transmission is very rare. Men who have sex with men can only contract or transmit chlamydia during sex.

Symptoms usually appear between 2 and 14 days after intercourse, but may take up to 21 days to appear. However, often, chlamydia has no symptoms or these go unnoticed, especially in the throat or anus.

Symptoms include:

  • Purulent discharge through the urethra (more accentuated in the morning)
  • Irritation or pain around the urethra
  • Stinging or pain when urinating
  • Pain in the testicles
  • Pain when ejaculating
  • Abnormal discharge through the anus
  • Itching and pain when defecating
  • Pain and discharge in the throat

The similarities of the most common symptoms and signs of chlamydia infection with gonorrhea make it advisable to always rule out both in the screening tests that are carried out.


Chlamydia can be diagnosed by pharyngeal or rectal samples as well as gonorrhea. The effectiveness of screening tests for chlamydia is very high and the results are usually available in 5 days.

The different techniques used in the diagnosis of C. trachomatis have been evolving over the last few years and nowadays, the application of nucleic acid amplification techniques are those that have been shown to be more sensitive and specific, whose results can be seen less affected by the transport and conservation of samples. The detection of C. trachomatis using STD Clean has been supported by multiple scientific investigations, these home diagnostic tests allow the detection of Chlamydia antigens in less 15 minutes with high clinical precision.

In view of the global growth of infection by this microorganism, the Center for Disease Control and Prevention (CDC) developed a screening program for the diagnosis of HIV and other STIs, among which is C. trachomatis. In this program, the culture of C. trachomatis and N. gonorrhoeae is performed annually from urethral and rectal samples in men who have sex with men and practice receptive anal sex; recommending screening every 3-6 months in this population, which is considered high risk, due to their sexual practices and the asymptomatic course of the infection.


The treatment involves the use of macrolide-type antibiotics that can be administered in a single dose or for 7 days. If treatment is not applied it can produce inflammation of the testicles, sterility and anal fibrosis. The treatment in addition to cure ends the transmission but does not immunize against future infections.


The use of condoms in anal and oral sex can reduce the risk of infection. If sex toys are used, it is recommended to cover them with a new condom for each person and each sexual practice (oral and/or anal) with which they are going to be used. There is no vaccine for chlamydia, but now some laboratory tests with promising results open the way to a possible vaccine in the future.