Background: Lymphogranuloma venereum (LGV) has been reported among men who have sex with men (MSM) since 2003. In France, the LGV testing recommendations of the National Reference Center (NRC) for bacterial STIs changed from universal to selective testing in 2016 in order to perform LGV diagnostic only for patients who had symptoms of proctitis and/or who were known to be living with HIV. Changes in tested populations lead to non-comparable LGV rates over time. To investigate LGV trends between 2020 and 2022, we performed a national survey based on universal LGV testing.
Methods: Every year, for three consecutive months, French participating laboratories sent all C. trachomatis-positive anorectal samples to the NRC for LGV diagnosis. Patients’ demographic, clinical, and biological data were collected. Genovars L of C. trachomatis were detected using real-time PCR targeting the pmpH gene. For all LGV-positive samples, the ompA gene was sequenced to identify the genovar.
Results: Overall, we analyzed 3666 C. trachomatis-positive anorectal samples. LGV positivity was 13.7% (166/1215) in 2020, 16.9% (170/1005) in 2021, and 13.4% (194/1446) in 2022 (p >0.05). Among LGV cases, proportions of HIV-positive remained stable over the period, ranging from 38.6% to 39.4%. However asymptomatic rectal LGV increased from 29.5% (49/166) in 2020 to 40.2% (78/194) in 2022 (p < 0.05). Among PrEP users, LGV positivity varied from 15.1% (56/371) in 2020, 16.6% (46/276) in 2021 to 12.7% (53/418) in 2022 and 40% did not report anorectal symptoms. The prevalence of LGV was not statistically different among PrEP users versus the general MSM population studied (p >0.05). The ompA gene sequencing showed that LGV cases were mainly caused by genovar L2 (from 50% to 64.1%), followed by different L2b genovariants (from 14.4% to 15.9%). Genovariant L2b decreased over time, representing only 7.7% of LGV cases in 2022. Notably, we observed an increasing number of LGV infections by L1 genovariant, from 1.2% in 2020 to 7.2% in 2022.
Conclusion: LGV prevalence has not increased in France but in contrast to previous reports, we found increasing proportions of asymptomatic cases among LGV-positive patients, up to 40% in 2022. LGV prevalence was similar in PrEP and non-PrEP users.
