Wolfgang Michael Bauer

Summary Background and Objectives Serovar L1–L3 of Chlamydia trachomatis (CT) causes lymphogranuloma venereum (LGV). A surge in LGV‐cases has been observed among HIV‐positive men who have sex with men (MSM). Discrimination between LGV and non‐LGV is pivotal since it has major treatment implications. Here, we aimed to determine the prevalence and characteristics of LGV among CT‐infections. Patients and Methods All CT‐positive results from 04/2014–12/2021 at the four largest Austrian HIV and STI clinics were evaluated. Disease characteristics and patient demographics were analyzed. Results Overall, n = 2,083 infections of CT were documented in n = 1,479 individual patients: median age was 31.4 years, 81% were male, 59% MSM, 44% HIV‐positive, 13% on HIV pre‐exposure‐prophylaxis. Available serovar analyses (61% [1,258/2,083]) showed L1–L3 in 15% (192/1,258). Considering only MSM with rectal CT‐infection, LGV accounted for 23% (101/439). Cases of LGV vs. other CT‐infections were primarily MSM (92% [177/192] vs. 62% [1,179/1,891], p < 0.001), more often HIV‐positive (64% [116/180] vs. 46% [631/1,376]; p < 0.001) and had frequently concomitant syphilis infection (18% [32/180] vs. 7% [52/749]; p < 0.001). LGV commonly manifested as proctitis (38% [72/192]) whereas 45% (87/192) were asymptomatic. Conclusions Lymphogranuloma venereum accounted for 23% of rectal CT‐infections in MSM. Furthermore, 45% of all LGV‐cases were asymptomatic. In the absence of CT‐serovar analysis, a high LGV prevalence should be considered in risk‐populations and guide empiric treatment selection.