We describe a change in the molecular epidemiology of Chlamydia trachomatis strains involved in an outbreak of rectal lymphogranuloma venereum in France during January 2010-April 2015. Until 2012, the C. trachomatis L2b strain predominated; however, starting in 2013, most cases involved the L2 strain. We also identified 4 genetic L2b ompA variants.

ObjectivesWe evaluated the prevalence of lymphogranuloma venereum (LGV) in anorectal Chlamydia trachomatis-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.MethodsLaboratories throughout French metropolitan areas performing routine testing for C. trachomatis sent positive anorectal specimens to the National Reference Centre for bacterial STIs for LGV real-time PCR targeting the pmpH gene. Identification of the C. trachomatis genovar was performed by ompA gene sequencing. For each patient, clinical, biological and sexual behaviour data were collected after obtaining written informed consent.ResultsIn 2017, 486 anorectal C. trachomatis-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. OmpA gene sequencing, successful in two-thirds of anorectal C. trachomatis-positive specimens, showed that the LGV cases were mainly of variant L2b (n=33), followed by genovar L2 (n=27) and genetic L2b ompA variants (n=16). In 11 cases, the results indicated the occurrence of genetic exchange between L and non-L genovars.ConclusionsLGV was diagnosed in 18.7% of anorectal C. trachomatis-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.

The objective of this article is to describe the epidemiology of lymphogranuloma venereum (LGV) and non-LGV Chlamydia trachomatis anorectal infections in France and to examine the characteristics of the affected populations via a voluntary sentinel surveillance system for LGV between 2010 and 2015. Anorectal samples positive for C. trachomatis (CT) were sent by the participating laboratories to the National Reference Center for CT for LGV identification. Biological and clinical data were collected by biologists and clinicians. There were 1740 LGV episodes and 2248 non-LGV episodes. Continuous monitoring highlighted a sharp increase in the number of LGV and non-LGV anorectal infections, which were 2.3-fold and 6.5-fold, respectively. Most of the infections occurred in men who have sex with men. LGV patients were older than non-LGV patients and were more frequently human immunodeficiency virus (HIV)-positive compared to non-LGV patients. Anorectal LGV was significantly associated with residence in Paris, HIV co-infection, concurrent syphilis and bloody anal discharge. Undocumented patient characteristics were strongly associated with anorectal LGV. The anorectal LGV epidemic is poorly controlled in France. Early detection and prompt treatment of patients and their sexual partners are required to prevent transmission in the context of pre-exposure prophylaxis (PrEP) for HIV infection.

In the span of 6 years, 56 extrarectal LGV cases were confirmed through genotyping in France. Extrarectal LGV seemed to share a common epidemiological background with rectal disease in terms of affected population and genovar distribution. HIV prevalence was lower than expected.