Snapshot A 5-year-old girl presents to the community clinic with a complaint of an intensely irritating foreign-body sensation in her left eye. On physical exam, she exhibits erratic twitching of her eyelid, inflammatory thickening of the upper tarsal conjunctiva, and evidence of conjunctival scarring. The girl and her family recently arrived in the United States from a refugee camp in Ethiopia, where they lived in crowded sleeping arrangements and had inadequate water access for personal hygiene. Introduction Classification Chlamydia trachomatis obligate intracellular bacteria Pathogenesis transmission sexual intercourse passage through birth canal trachoma transmitted by hand-to-eye contact and flies location of infection genital tract eyes molecular biology obligate intracellular organism cannot make their own ATP requires live cells for growth in laboratory 2 forms reticulate body intracellular, metabolically active, replicating form "Reticulate Replicates" collections of reticulate bodies can be seen in the cytoplasm under light microscopy and are called "inclusion bodies" elementary body infectious, inactive, extracellular form small, dense "Elementary is Enfectious and Enters cell via Endocytosis" infection of mucosal surfaces leads to granulomatous response and damage cell wall lacks peptidoglycan beta-lactam antibiotics are thus ineffective Diseases trachoma most common cause of preventable blindness serotypes A, B, C chlamydia the most common bacterial STD in the United States serotypes D-K lymphogranuloma venereum serotypes L1-3 ("L for lymphogranuloma") Associated conditions co-infection with Neisseria gonorrhoeae pelvic inflammatory disease (PID) Presentation Trachoma itching and irritation of the eyes and eyelids discharge from the eyes containing mucus or pus eyelid inflammation blepharospasm conjunctival scarring trichiasis (inward-growing eyelashes) Chlamydia in females dysuria yellow mucopurulent discharge from the urethra vaginal discharge abnormal vaginal bleeding dyspareunia fever (in pelvic inflammatory disesease) asymptomatic in 80% of patients in males dysuria yellow mucopurulent discharge from the urethra unilateral pain and swelling of the scrotum fever asymptomatic in 50% of patients in newborns symptoms of conjunctivitis beginning at 1-2 weeks eye discharge eyelid swelling symptoms of pneumonia beginning at 1-3 months cough fever Lymphogranuloma venereum painful, localized inguinal adenopathy (buboes) genital ulceration Studies Laboratory diagnosis polymerase chain reaction (PCR) nucleic acid amplification test (NAAT) cytology for diagnosing infant conjunctivitis and trachoma visualization of intracytoplasmic inclusions Histology cytoplasmic inclusions (reticulate bodies) seen on Giemsa or fluorescent antibody-stained smear Additional studies pregnancy test for females with suspected chlamydial infection doxycycline contraindicated in pregnancy strongly consider testing sexual partners for Chlamydia Differential Bacterial vaginosis distinguishing factor gray vaginal discharge with a fishy smell Trichomonas vaginitis distinguishing factor frothy, yellow-green discharge motile trichomonads on wet mount Urinary tract infection distinguishing factor lack of cytoplasmic inclusions seen on Giemsa or fluorescent antibody-stained smear Treatment Medical azithromycin (one-time treatment) treatment of choice for pregnant patients doxycycline add ceftriaxone for possible concomitant N. gonorrhoeae infection contraindicated in pregnant patients due to risk of teeth discoloration in the fetus topical and oral erythromycin for neonatal chlamydial conjunctivitis Complications Pelvic inflammatory disease (PID) may include salpingitis endometritis hydrosalpinx tubo-ovarian abscess risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and adhesions