Rapid expansion of lymphogranuloma venereum infections with fast diversification and spread of Chlamydia trachomatis L genovariants.

IMPORTANCE: Numerous international organizations, including the World Health Organization, have been drawing attention to the global increase in sexually transmitted infections. Twenty years ago, lymphogranuloma venereum (LGV) was mainly considered a tropical disease; in recent decades, however, LGV has been increasingly present in high-income countries. This increase has been linked to men who have sex with men who participate in highly interconnected sexual networks, leading to a rapid spread of LGV. This study focuses on the spread of LGV, presenting the largest time series of LGV prevalence in Spain, which includes more than a thousand diagnosed cases in one large city. The number of LGV cases diagnosed was analyzed over time, and a selection of strains was subjected to molecular genotyping. The results indicate that the LGV epidemic is gradually evolving toward an increasingly complex diversification due to the selection of successful genovariants that have emerged by mutation and recombination events, suggesting that we are moving toward an unpredictable scenario.