Chlamydia trachomatis infection

Chlamydia trachomatis infection refers to infection with C. trachomatis, a bacterial pathogen associated in the sources with infection of the genitals, rectum, and pharynx ^[1]. In the provided material, the same organism is also linked to trachoma, a neglected tropical disease involving repeated conjunctival infection ^[2]. Beyond these site-based disease descriptions, source-backed detail on further etiologic characterization is not yet available ^[1][2].

The genital infection is often clinically silent, with more than 80% of cases reported as asymptomatic ^[1]. When symptomatic or complicated, genital chlamydia in women may ascend to the upper genital tract and cause pelvic inflammatory disease, with increased risk of ectopic pregnancy, infertility, and chronic pelvic pain ^[1]. In men, the cited complications include epididymitis and proctitis ^[1]. For trachoma, the clinical course begins with recurrent conjunctivitis in childhood and may progress, if untreated, to conjunctival scarring and later in-turned eyelashes (trachomatous trichiasis), with blinding complications ^[2].

Genital chlamydia is described as the most commonly diagnosed bacterial sexually transmitted infection globally ^[1]. The trachoma literature in the provided sources identifies a different epidemiologic pattern, affecting mainly the poorest and most rural communities with limited access to water and hygiene facilities ^[2]. Trachoma is also framed as the leading infectious cause of blindness worldwide and as one of the neglected tropical diseases targeted by WHO for elimination by 2030 ^[2]. As of December 2024, 21 countries had eliminated trachoma as a public health problem, while persistent and recrudescent active trachoma remains a challenge in some populations ^[2].

For genital infection, the sources indicate infection at mucosal sites including the urethra, vagina/cervix, rectum, and pharynx, which is consistent with sexually associated exposure, but they do not further specify transmission mechanisms ^[1]. For trachoma, the available material emphasizes repeated conjunctival infection in childhood and notes that limited access to water and hygiene facilities is part of the exposure setting ^[2]. More granular source-backed detail on direct person-to-person spread, fomites, or other routes is not yet available in the provided snippets ^[1][2].

Source-backed higher-burden groups include people with genital exposure at the urethra, vagina/cervix, rectum, or pharynx, although the snippets do not further stratify risk by age or behavior ^[1]. For trachoma, the provided material identifies the poorest and most rural communities with limited water and hygiene access as the main affected populations ^[2]. It also notes that blinding complications are most common in women who, in many cultures, care for infected children from a young age ^[2].

For trachoma, the source explicitly describes the SAFE package: surgery for trachomatous trichiasis, antibiotic mass drug administration, facial cleanliness, and environmental improvement to limit transmission ^[2]. The same source notes that these interventions have contributed to substantial progress toward elimination ^[2]. For genital chlamydia, the provided material mentions screening and control policy but does not give specific preventive measures beyond that, so source-backed detail is limited ^[1].

In surveillance, chlamydia should be interpreted as a major bacterial STI burden with many infections remaining asymptomatic, which can obscure measured prevalence and delay recognition of complications ^[1]. The same organism also produces trachoma, a distinct public-health signal in disadvantaged rural settings and a WHO elimination target, so ocular and genital disease should not be conflated in reporting ^[2]. The available sources do not provide standardized case definitions, testing algorithms, or notification thresholds, so those details are not yet source-backed here ^[1][2].

1. 1 Hocking JS et al. Update on the Epidemiology, Screening, and Management of Chlamydia trachomatis Infection. Infect Dis Clin North Am. 2023 Jun. PMID: 37005162. doi: 10.1016/j.idc.2023.02.007. PubMed: https://pubmed.ncbi.nlm.nih.gov/37005162/
2. 2 Habtamu E et al. Trachoma. Lancet. 2025 May 24. PMID: 40412861. doi: 10.1016/S0140-6736(25)00551-3. PubMed: https://pubmed.ncbi.nlm.nih.gov/40412861/
3. 3 Del Romero J et al. Sexually transmitted infections in Spain: Current status. Rev Esp Quimioter. 2023 Oct. PMID: 37335757. doi: 10.37201/req/038.2023. PubMed: https://pubmed.ncbi.nlm.nih.gov/37335757/
4. 4 Chlamydia trachomatis infection. BMJ. 1989. doi: 10.1136/bmj.299.6713.1466-b. DOI: https://doi.org/10.1136/bmj.299.6713.1466-b
5. 5 Chlamydia trachomatis Infection. Infectious Diseases. 2017. doi: 10.1016/b978-0-7020-6285-8.00066-6. DOI: https://doi.org/10.1016/b978-0-7020-6285-8.00066-6
6. 6 Chlamydia trachomatis Infection. Sexually Transmitted Infections in HIV-Infected Adults and Special Populations. 2017. doi: 10.1007/978-3-319-56694-8_3. DOI: https://doi.org/10.1007/978-3-319-56694-8_3

ICD-10

ICD-11

Total cases

12.5M

Peak month

2015-10

Coverage

3 reporting countries · 2000-01-01 → 2026-06-20