Observational study of anorectal Chlamydia trachomatis infections in France through the lymphogranuloma venereum surveillance network, 2010-2015.

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.