At present, 14 serovars of the biovar Chlamydia trachomatis (chlamydia trachomatis) are known, which cause more than 20 nosological forms: serovars A, B, B1, C cause trachoma and conjunctivitis with intracellular inclusions; serovars D, G, H, I, J, K cause urogenital chlamydia, conjunctivitis, pneumonia of newborns, Reiter's syndrome.