What causes Lymphogranuloma venereum?

Lymphogranuloma venereum (LGV) is caused specifically by a type of the bacterium Chlamydia trachomatis. This is a distinct serovar (serovars L1, L2, and L3) of Chlamydia trachomatis that is responsible for this particular disease. LGV primarily affects the lymphatic system and is characterized by the formation of painful lymphadenopathy and ulcerative lesions, primarily in the genital area.

Infection typically begins as a small, painless ulcer at the site of entry, followed by swelling of the lymph nodes, which can lead to complications if left untreated. The specific strain involved in LGV is particularly associated with proctitis and systemic symptoms unlike other forms of chlamydia infections that may not exhibit such significant systemic involvement.

Other options present different pathogens that cause various sexually transmitted infections but are not responsible for LGV. For instance, Human Papillomavirus (HPV) is responsible for warts and can lead to cancers but does not cause LGV. Trichomonas vaginalis is a protozoan that results in trichomoniasis, and Neisseria gonorrhoeae is responsible for gonorrhea but does not lead to lymph