STI's (1/18) Flashcards
What are common causes of urethritis?
Urethritis = uretheral inflammation
Gonorrhea, chlamydia, and mycoplasma genitalium are common causes
What is Neisseria gonorrhoeae?
Gram negative diplococcic, kidney bean shaped
Aerobic, non-motile, non spore forming
Require CO2 enriched atmosphere for optimal growth; oxidase positive; ferments glucose only v. N. meningitidis which also ferments maltose
2nd most common STI
Recurrent infection is common bc of asymptomatic infected person as reservoir (especially men)
What features of N. gonorrhea lead to pathogenesis?
Pilin: attaches to membrane
Porin: induces endocytosis
OPA: opacity related proteins, binds epithelial cells
IgA protease in secretions produces host IgA
How do you diagnose gonococcal infection?
Gram stain is useful in men with GC urethritis, not women, bc there are other bacteria in the vagina that interfere with gram stain
Culture: from every orifice
Nucleic acid amplification assays: best method, can detect one organism, not FDA approved so validation study is required
What are the symptoms of gonorrhea?
Men: purulent urethral discharge, dysuria
Women: infects endocervix → increased vaginal discharge, frequency, dysuria, abd pain, vag bleeding
Co infection with chlamydia is 30%!
What are other manifestations of gonorrhea?
Epididymitis, prostatis
Bartholin’s gland abscess (gland that secretes mucous in vagina)
Pharyngeal infection
Rectal infection (proctitis)
PID (infertility, ectopic pregnancy)
Ophthalmia neonatorum
Disseminated infection
What is disseminated gonococcal infection?
Fever, pustular skin lesions, tenosyovitis, septic arthritis in 1-2 joints, endocarditis, meningitis
How do you treat gonorrhea?
3rd gen cephalosporins
Quinolones no longer used bc of resistance
2g azithromycin for uncomplicated GC
Presumptively treat for chlamydia: one dose of azithromycin or 7 day course of doxycycline
What is Chlaymdia trachomatis?
Obligate intracellular parasite
Most frequently reported infectious disease
Inner/outer membranes = similar to gram neg bacteria, but lack rigid peptidoglycan layer
What is the life cycle of chlamydia?
Elementary body gets in to ET cell, forms reticular body, organizes back into elementary body, exudes outside the cell and infects another cell
What are the clinical manifestations of Chlamydia?
Clinical manifestation is similar to gonorrhea (latent period is longer)
Urethritis, epididymitis, prostatitis, proctitis, PID in women
Cervicidis may be asymptomatic but then lead to PID, infertility, ectopic pregnancy
Reiter’s syndrome = autoimmune – arthritis, urethritis, uveitis, conjunctivitis, and skin lesions
Newborn inclusion conjunctivitis is not prevented by antimicrobial drops at birth
How do you diagnose chlamydia?
Nucleic acid amplification tests (test of choice – use urethral, cervical samples, urine and vaginal swabs… prefer to use combo NAAT assay for GC and chlamydia)
Cell culture (less sensitive)
Serology for LGV
How do you treat chlamydia?
Azithromycin (best) or doxycycline
What is pelvic inflammatory disorder?
Can be caused by gonorrhea or chlamydia (10-20% of these go on to cause PID)
Can cause infertility, ectopic pregnancy, chronic pelvic pain
What is LGV?
Chlamydia trachomatis can cause a lymphogranuloma vereneum
Primarily is a painless genital lesion
Secondary symptoms include tenderness, constitutional symptoms (fever, headache, myalgia), proctocolitis
Can cause draining sinus tracts, urethral/rectal strictures, lymphatic obstruction, chronic hard inguinal masses
Diagnose with NAAT for CT, serology, PCR
