NOTES NOTES CHLAMYDIA MICROBE OVERVIEW ▪ Gram-negative, obligate intracellular bacteria ▪ AKA “energy parasites”; rely on host cell for adenosine triphosphate (ATP) synthesis ▪ Primarily infects epithelium, mucous membranes Morphology ▪ Coccoid; cell walls don’t contain peptidoglycan Replication ▪ Intracellular life cycle: infectious stage (spore-like elementary body) attaches to host cell via endocytosis → reorganizes within cellular vacuole into reticulate body (vegetative form) → reproduces, forms multiple reticulate bodies → forms elementary bodies → released from host cell → continues infectious process CHLAMYDIA SPECIES (PNEUMONIA) osms.it/chlamydia-species PATHOLOGY & CAUSES ▪ Species of chlamydia; primarily causes community-acquired pneumonia ▪ Transmitted via respiratory secretions ▪ Can also infect endothelial cells → atherosclerosis 342 OSMOSIS.ORG RISK FACTORS ▪ ↑ risk with age COMPLICATIONS ▪ Otitis media, sinusitis, parapneumonic effusions, pericarditis
Chapter 62 Chlamydia SIGNS & SYMPTOMS ▪ Gradual onset ▪ General malaise, myalgia, fever, chills, pharyngitis, hoarseness, sinusitis, cough ▪ Extra-respiratory manifestations: meningoencephalitis, reactive arthritis, myocarditis DIAGNOSIS LAB RESULTS ▪ Microbial identiﬁcation: serology, polymerase chain reaction (PCR), nasopharyngeal swab culture, direct antigen testing ▪ Complete blood count (CBC): normal white blood cell count OTHER DIAGNOSTICS ▪ History, physical examination: lung sounds (e.g. crackles, wheezing) DIAGNOSTIC IMAGING Chest X-ray ▪ Unilateral patchy inﬁltrates TREATMENT MEDICATIONS ▪ Antibiotics CHLAMYDIA TRACHOMATIS osms.it/chlamydia-trachomatis PATHOLOGY & CAUSES ▪ Species of chlamydia; primarily affects eyes, urogenital tract ▪ Different serovars cause diverse disease states ▫ A, B, Ba, C: trachoma ▫ D–K: urogenital infection, conjunctivitis ▫ L1, L2, L2a, L2b, L3: lymphogranuloma venereum RISK FACTORS ▪ Risky sexual practices (e.g. multiple sex partners, unprotected sex) ▪ Impaired mucous membrane barrier (e.g. cervical friability) ▪ History of sexually transmitted disease ▪ Exposure during birth COMPLICATIONS ▪ Ocular: ophthalmia neonatorum (conjunctivitis), blindness ▪ Genitourinary: pelvic inﬂammatory disease (PID), PID-associated ectopic pregnancy, infertility, proctitis, cervicitis, urethritis ▪ Chlamydial pneumonia, bronchitis, perihepatitis (Fitz-Hugh–Curtis syndrome); ↑ risk of acquiring/transmitting HIV due to genital inﬂammation SIGNS & SYMPTOMS Trachoma ▪ Chronic, granulomatous inﬂammation of eye → corneal ulceration, scaring, pannus formation → blindness Adult conjunctivitis ▪ Inclusion (purulent erythematous injection of epithelial surface) conjunctivitis, mucopurulent discharge → keratitis Urogenital infections ▪ Individuals who are biologically female ▫ May be asymptomatic ▫ Bartholinitis, cervicitis (mucopurulent endocervical discharge), endometritis, salpingitis, urethritis (dysuria, pyuria) ▫ PID: uterine/adnexal tenderness ▫ Perihepatitis: right upper quadrant (RUQ) pain OSMOSIS.ORG 343
▪ Individuals who are biologically male ▫ Urethritis: dysuria, watery/mucoid discharge Neonatal conjunctivitis ▪ Eyelid swelling, watery/purulent discharge, red, thickened conjunctiva (chemosis) ▪ Conjunctival scarring, corneal vascularization ▪ ↑ risk of developing C. trachomatis pneumonia Infant pneumonia ▪ Diffuse, interstitial disease; rhinitis, staccato cough Figure 62.1 Purulent discharge from the cervix of an individual with chlamydia infection. Lymphogranuloma venereum (LGV) ▪ Anorectal disease: anorectal pain, tenesmus (feeling of incomplete bowel evacuation), rectal bleeding/discharge, constipation ▪ Painless ulcer → inﬂammation of lymph nodes (preauricular, submandibular, cervical) → progression to systemic symptoms ▪ Population at highest risk: individuals who are biologically male who have same-sex intercourse (MSM) DIAGNOSIS LAB RESULTS ▪ Microbial identiﬁcation: nucleic acid ampliﬁcation test (NAAT) OTHER DIAGNOSTICS ▪ Clinical presentation, history TREATMENT MEDICATIONS ▪ Antibiotics ▪ Sexual partners should also be treated 344 OSMOSIS.ORG Figure 62.2 A cervical smear from an individual infected with Chlamydia trachomatis. There are numerous organisms contained within intracellular vacuoles.