Clinical meaning
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.
Diagnosis & workup
Diagnostics & workup: - Order NAAT (sensitivity >95%, specificity >99%) on first-void urine, endocervical, vaginal, pharyngeal, or rectal swab based on exposure history - Order comprehensive STI panel: gonorrhea NAAT, HIV Ag/Ab, RPR/VDRL, hepatitis B surface antigen - Assess for PID using CDC clinical criteria: cervical motion tenderness, uterine tenderness, or adnexal tenderness - Order pelvic ultrasound if tubo-ovarian abscess is suspected - Consider LGV testing (rectal chlamydia NAAT with genotyping) in MSM with proctitis - Order pregnancy test before initiating treatment to guide antibiotic selection