Chlamydia

Chlamydia trachomatis is an obligate intracellular pathogen with a unique biphasic life cycle alternating between infectious elementary bodies (EBs) and metabolically active reticulate bodies (RBs). The organism evades immune clearance through antigenic variation and inhibition of phagolysosomal fusion. Repeated infections cause a robust inflammatory response with tissue fibrosis and scarring, particularly in the fallopian tubes. Serovars D-K cause urogenital infections, while serovars L1-L3 cause lymphogranuloma venereum (LGV), a more invasive variant seen in MSM. The clinician must apply evidence-based prescribing guidelines, manage complicated presentations including PID and epididymo-orchitis, implement population-level screening strategies, and address antibiotic stewardship in STI management.