Prevalence of lymphogranuloma venereum among anorectal -positive MSM using pre-exposure prophylaxis for HIV.

Objectives: We evaluated the prevalence of lymphogranuloma venereum (LGV) in anorectal -positive French men who have sex with men (MSM) using pre-exposure prophylaxis (PrEP) for HIV. Here, we describe the clinical, biological and behavioural characteristics of these patients.

Methods: Laboratories throughout French metropolitan areas performing routine testing for sent positive anorectal specimens to the National Reference Centre for bacterial STIs for LGV real-time PCR targeting the H gene. Identification of the genovar was performed by A gene sequencing. For each patient, clinical, biological and sexual behaviour data were collected after obtaining written informed consent.

Results: In 2017, 486 anorectal -positive specimens from MSM PrEP users were analysed. A strain of genovar L was detected in 91 cases (18.7%). Patients with LGV were significantly more symptomatic, had more sexual partners and more concurrent syphilis compared with their non-LGV counterparts. A gene sequencing, successful in two-thirds of anorectal -positive specimens, showed that the LGV cases were mainly of variant L2b (n=33), followed by genovar L2 (n=27) and genetic L2b A variants (n=16). In 11 cases, the results indicated the occurrence of genetic exchange between L and non-L genovars.

Conclusions: LGV was diagnosed in 18.7% of anorectal -positive specimens from French MSM using PrEP. LGV testing should be carried out for MSM diagnosed with chlamydia and with a large number of sexual partners, high-risk practices and anorectal symptoms. These patients should be presumptively treated as having LGV. This is the first surveillance study of LGV among MSM PrEP users and monitoring should continue.