05 Bacterial infections Flashcards
impetigo
superficial skin infection, contact sports, scratching.
strep pyogenes (non-bullous), staph aureus (bullous).
vesicles rupture and cover with brownish crust.
treatment: non-bulous - mupirocin, bullous - antibiotics.
tonsillar plug
treponema pallidum
causes syphilis, treated with antibiotics.
highly infectious during first 2 stages, pregnancy transmission.
primary syphilis
chancre at initial exposure site - firm painless skin ulceration, 4-6week duration, regional lymphadenopathy.
secondary syphilis
1-6 months post primary, flu-like.
symmetrical reddish, non-itchy skin rash.
mucous patches - genitals/mouth.
condyloma lata (flat, whitish rash in moist areas).
optic neuritis and interstitial keratitis
latent syphilis
serologic proof without signs/symptoms.
early more contagious - treat with single, long acting penicillin.
late less contagious - treat with three weekly injections
tertiary syphilis
1-10yrs post infection.
cardiovascular, central nervous system trouble.
gumma - soft tumor-like granulomas of skin or mucous membranes anywhere on body.
leutic glossitis
neurologic syphilis
insanity (general paresis) during late stage.
personality/emotional changes, thin/irregular pupils.
tabes dorsalis - spinal cord disorder leads to shuffling gait.
syphilitic aortitis, aortic aneurysm, aortic regurgitation.
neurosyphilis higher w/HIV, lumbar puncture recommended.
congenital syphilis
mother with primary/secondary syphilis.
usually results in miscarriage, premature birth, stillbirths.
signs: frontal bossing, short maxilla, high arched palate, saddle nose, rhagades.
most symptoms develop after birth and are infectious.
rash, fever, swollen liver/spleen, anemia, jaundice.
newborns may develop poor feeding and rhinorrhea.
hutchinson’s triad: hutchinson’s teeth, interstitial keratitis, 8th nerve deafness
syphilis tests
wasserman test
darkfield illumination microscopy of fluid
rapid plasma reagin (RPR), venereal disease research laboratory (VDRL) - cheap, not specific.
most specific tests use monoclonal antibodies and IF: treponema pallidum hemagglutination test (TPHA), fluorescent treponemal antibody absorption (FTA-ABS)
gonorrhea
neisseria gonorrhea, gram negative diplococci.
sexual contact, cannot penetrate intact epithelium.
pelvic inflammatory disease (PID).
associated with chlamydia, cotreat all cases for both with ceftriaxone and doxycycline.
gonococcal ophthalmia neonatum (baby eye infection).
gonococcal pharyngitis
tuberculosis
mycobacterium tuberculosis.
infection must be distinguished from active disease.
attacks lungs, CNS, lymph, circulatory system, bones, joints, skin, etc.
50% lethal if untreated.
aerosol spread from active infection, not latent.
dangerous for immunocompromised and health care workers of high risk patients.
TB & HIV
HIV w/PPD+, uninfected - 1:10 chance developing active TB, highest in first 2 years and later in life.
HIV w/PPD+, infected - 1:8 chance developing active TB each year.
TB treatment
isolation until 3 AFB- sputum
direct observed therapy, multiple drugs.
prophylaxis: INH, rifampin, pyrazinamide
BCG vaccine effective for infants