Bacterial infections III - atypicals Flashcards
3 atypical causes of pneumonia
- mycoplasma
- legionella
- chlamydia
mycoplasma are small bacteria lacking ____
a cell wall
mycoplasma are commonly found where?
lining mucous membrane of:
1. rsp tract (especially)
2. genitourinary tract
___ is most associated with acute pneumonia
M. pneumoniae
mycoplasma causes ___ (2)
epithelial injury
activates immune response
what causes the milder form of “pneumonia” and is often associated with bullous myringitis and referred to as “walking pneumonia”
M. pneumoniae
presentations of M. pneumoniae
- clear auscultation
- no lobar consolidated
- diagnosed by NP swab**
clinical suspicion of M. pneumoniae in CAP what should be initiated?
empiric tx
azithromycin (z pack)
what is an obligate intracellular bacteria that does not contain a peptidoglycan cell wall
chlamydia
what is the second most common cause of “atypical” pneumonia
chlamydia pneumoniae
what causes an “atypical” pneumonia with fever, chills, cough, HA and comes from contact with birds?
chlamydia psittaci
tx to chlamydia psittaci
tetracycline
erythromycin
what is the most common STD
chlamydia trachomatis
clinical manifestations of chlamydia
female:
- cervicitis
- urethritis
- PID
male:
- urethritis
- epididymitis
- prostatitis
BOTH:
- conjunctivitis
- lymphogranuloma venereum*
typical presentation of chlamydia
pain, tenderness, inflamed
mucopurulent/mucoid/watery discharge
is gram stain helpful for chlamydia trachomatis?
no! they have no cell wall
screening for chlamydia is recommended for:
- pregnancy
- sexually active females +25 y/o
- positive risk factors
DDX of cervicitis
- chlamydia
- gonorrhea
- trichomoniasis
- BV
- candidiasis
- HSV
tx for urogenital chlamydia
azithromycin PLUS ceftriaxone (for gonorrhea)
complications with chlamydia trachomatis
- periphepatitis (fitz Hugh-curtis syndrome)
- pregnancy complications - PROM (premature rupture of membranes)
- infertility (from PID)
- transmission to newborn
3 spirochetes
- treponema pallidum - syphilis
- borrelia - lyme disease
- leptospira - leptospirosis
clinical stages of syphilis
- primary
- secondary
- tertiary/late
- neurosyphilis
- latent
clinical manifestations of primary syphilis
appears 2-4 wks after contact
chancre* - painless ulcer
spontaneous healing
steps into diagnosing primary syphilis
- culture ulcer via dark field microscopy
- non-treponemal antibody test
- treponemal antibody tests - after #2 is positive
tx for primary syphilis
benzathine PCN G single dose
when is syphilis considered secondary
begins several weeks to 6 months after chancre - disseminates of T. pallidum through body (systemic infection!)
*still infectious
work-up and tx for secondary syphilis is the same as ____
primary syphilis
2 types of latent syphilis
- early - within 1st year after primary infection - STILL INFECTIOUS
- late - after 1st year of latent infection - NONINFECTIOUS
how does tertiary/late syphilis occur?
occurs any time after UNTREATED secondary syphilis (rare)
presence of gummas is indicative of ?
tertiary/late syphilis
infiltrative tumors that can go to the skin, bones, internal organs
neurosyphilis is most common in what stage?
late syphilis
can still occur in any stage of disease
disease course of neurosyphilis
- asx
- meningovascular syphilis - meningeal symptoms
- tabes dorsalis - progressive degeneration of posterior columns of spinal cord
- general paresis - involvement of cerebral cortex
- personality change
- memory loss
- psychosis
- slurred speech
- dysarthria
- tremors
diagnosis/tx for neurosyphilis
- LP (diagnose)
- PCN
risk factors of neurosyphilis
- HIV
- Non-HIV
- males
- +45 y/o
what is the most common mode of transmission of borrelia burgdorferi
ticks
stage 1 of lyme disease
- erythema migrans* - flat “bulls’ eye” lesion with central clearing
- occurs 1 wk after tick bite - flu-like
(resolves 3-4 wks w/o tx)
stage 2 of lyme disease
early disseminated infection
1. bacteremia
2. secondary lesions and rash
3. worsening flu symptoms
4. cardiac involvement - arrhythmias and HB (4-10% of pts)
5. neurologic manifestations - aseptic meningitis, facial palsy (10-15% of pts)
stage 3 of late persistent infection of syphilis
- MSK (60%)
- neurologic
- skin
criteria for lyme disease diagnosis
exposure to tick bite who:
- developed erythema migrans
or
- at least one late manifestation
AND
- lab confirmation
to have lab confirmation of lyme disease, you order
ELISA - detects antibodies to B. burgdorferi
Western Blot
tx for lyme disease
doxy for 2-4 wks
leptospirosis is transmitted by ?
ingestion of food/drink contaminated by urine of infected animal (rat)
tx for leptospirosis
doxycycline
rocky mountain spotted fever is transmitted via
ticks! tick bourne illness
what is the most serious rickettsia disease
rocky mountain spotted fever
presentation of rocky mountain spotted fever
Rash*
- faint macules progressing to papules, then to petechiae
- appears first on wrists and ankles and spreads from distal to proximal
what is the tx for rocky mountain spotted fever
doxy! within 5 days
NO AMOXICILLIN
what is the rickettsia disease that is commonly seen with tick vectors in tropical settings
typhus
what is the rickettsia disease that is commonly seen with tick vectors in southern US
ehrlichiosis
what is the rickettsia disease that is commonly seen with flea and body lice vectors throughout the US
anaplasma
what is the general tx for rickettsia diseases?
doxy
