Clinical Characteristics and Trends of Lymphogranuloma Venereum Versus Non-LGV Chlamydia trachomatis Anorectal Infections: A Six-Year Retrospective Study.

BACKGROUND

Chlamydia trachomatis (CT) is a common cause of anorectal infections, with L1-L3 serovars leading to lymphogranuloma venereum (LGV), a more severe invasive clinical syndrome. This study aimed to estimate the prevalence and temporal trends of LGV and non-LGV anorectal CT infections, and to compare their clinical and epidemiological characteristics in a high-risk population.

METHODS

We conducted a retrospective analysis of anorectal CT infections diagnosed at Hospital Universitario 12 de Octubre, a high-complexity healthcare center in Madrid, Spain, between January 2019 and December 2024. All CT-positive samples were further tested to differentiate LGV from non-LGV serovars. Demographic, clinical, and behavioral data were collected and compared between groups.

RESULTS

Throughout the study period, the number of tests performed increased substantially, whereas the overall CT positivity rate declined. Among 8690 samples, 719 (8.3%) were CT-positive, with 236 (32.8%) confirmed as LGV. The proportion of LGV among CT-positive cases increased over time. Most LGV cases occurred in men who have sex with men (92.4%) and people living with human immunodeficiency virus (72.0%). LGV infections were more frequently symptomatic compared to non-LGV cases (58.4% vs 19.0%, P < 0.001), and were more commonly associated with co-infections such as Neisseria gonorrhoeae (38.1%) and syphilis (22.4%). High-risk behaviors, including chemsex and multiple concurrent sexual partners, were significantly more prevalent among individuals with LGV.

CONCLUSIONS

This study highlights that, despite a decline in overall CT positivity with increased testing, the proportion of LGV cases has risen in high-risk populations. LGV is more common among men who have sex with men and people living with human immunodeficiency virus, and is linked to more symptoms, co-infections, and risky sexual behaviors.