Infectious Disease Flashcards
First Aid and NEJM Knowledge + (137 cards)
Location of abnormal signal for meningitis 2/2
(a) HSV-1
(b) Tb
(a) Temporal lobes
(b) Basilar
Causes of persistent CSF pleocytosis:
lymphocytic vs. neutrophilic
Chronic meningitis most likely to be lymphocytic: weeks duration of elevated CSF white count
Lymphocytic- 40% Tb, atypical mycobacteria, cryptococcus 7% (HIV+ pts get cryptococcus meningitis), coccidio, histo, blasto
Neutrophilic- less common- nocardia, actinomyces, aspergillus, candida, SLE
Causes of persistent CSF eosinophilic pleocytosis
Coccidio, parasites, lymphoma, chemical agents
Mollaret’s syndrome
Recurrent HSV-2 meningitis
Bugs responsible for aseptic meningitis
fall vs. spring
Aseptic meningitis- typically viral w/ benign course
Late summer/early fall: enteroviruses (coxsackie) and arboviruses (arthropod-borne = eastern/western equine, St Louis)
Spring: mumps
What drugs typically can cause medication-induced aseptic meningitis
TMP-SMX, IVIG, NSAIDs, carbamazepine
Most common bugs that cause bacterial meningitis
(a) 18-50 yoa
(b) Over 50 yoa
(c) HIV
(d) Post-neurosurgical
Bacterial meningitis
(a) Typical adults: Strep pneumo and neisseria meningitis
(b) Over 50: S. pneumo, listeria monocytogenes, GN bacilli
(c) HIV: S. pneumo, listeria, GN bacilli (pseudomonas)
(d) Post-neurosurgical: S. pneumo then staph aureus, also GN bacilli
Empiric abx for bacterial meningitis in
(a) Typical adult
(b) Adult over 50
(c) HIV
(d) Post neurosurgical
(a) CTX, vanc
(b) CTX, vanc, ampicillin
(c) Ceftazidime (pseudomonal coverage), Vanc, Ampicillin
(d) Ceftazidime and Vanc
When to use steroids during empiric tx of meningitis
IV Dex 10mg q6h for 2-4 days when bacterial meningitis suspected due to Strep pneumo
CSF findings of traumatic tap
Expect some more cells
Correction factor: expect 800 RBCs per 1 WBC, expect 1mg protein per 1000 RBCs
Causes of CSF studies with
(a) Low glucose
(b) PMNs vs. lymphocytes
CSF studies
a) Low glucose: bacterial, fungal (Tb
(b) PMNs = bacterial
lymphocytic = fungal, viral
Who gets meningitis prophylaxis?
Rifampin for roommates, cellmates, close to respiratory secretions (ET tube, kissing, sharing utensils) within the last 7 days for suspected neisseria meningitis
CSF of bacterial vs. fungal meningitis
Bacterial- neutrophils
Fungal- lymphocytes
Then both w/ low glucose, high protein, high opening pressure (above 20)
List causes of chronic meningitis + cranial nerve palsy
- Lyme disease
- Syphilis
- Sarcoid (CN VII = Bell’s)
- Tb (CN VI)
Encephalitis plus causes
(a) plus flaccid paralysis
(b) plus rash
Encephalitis (headache, fever, nucchal rigidity PLUS focal neurologic sign)
(a) encephalitis preceded by flaccid paralysis in West Nile virus b/c it infects the anterior horn cells
(b) See a rash in VZV encephalitis (zoster rash), Lyme (targetoid), RMSF
Most common causes of encephalitis in the US
(a) Whichcarries the highest mortality
HSV and arboviruses (arthropod aka mosquito-borne): West Nile
(a) HSV encephalitis- mortality of 70%
Typical causes of encephalitis in
(a) Summer
(b) Fall
(c) Winter
Encephalitis bugs
(a) Summer- think tick-borne = Lyme, RMSF, Ehrlichiosis
(b) Fall- think mosquito/arthropod borne (arboviruses) = West Nile, east equine, west equine, St. Louis virus
(c) Winter- measles, mumps
Compare bugs that cause infective endocarditis of
(a) native valve
(b) prosthetic valve
(c) valve in IVDU
Infective endocarditis
(a) Native valve- Strep viridans, other strep. Then S. aureus and enterococcus
(b) Prosthetic valve- Staph epi, Staph aureus
(c) Staph aureus
Bacteremia of which 2 bugs should spark workup for GI pathology (search for colon CA)
Strep bovis
Clostridium septicum
What is marantic endocarditis
Nonbacterial thrombotic endocarditis = Marantic endocarditis = Libman-Sacks endocarditis
- noninfectious endocarditis due to deposition of thrombi on heart valves
- seen mostly in cancer and SLE
Libman-Sacks endocarditis
Libman-Sacks endocarditis = specific kind of noninfectious endocarditis seen in SLE due to autoantibodies against heart valves
Duke’s criteria
For diagnosing infective carditis: 2 major, 1 major w/ 3 minor, or 5 minor
Major criteria:
- new regurg murmur
- new oscillating vegetation on TTE
- BCx w/ typical organism
Minor criteria:
- Fever
- Predisposing condition: prosthetic valve, IVDU, valvular heart disease
- BCx w/ atypical organism
- Embolic phenomenon: Janeway lesion, pulm or intracranial infarcts, conjunctival hemorrhage
- Immunologic phenomenon: Osler nodes, glomerulonephritis, Roth spots
Indications for surgery in endocarditis
- Vegetation causing conduction abnormality: AV dissociation, new LBBB, PR prolongation (suggestive of abscess)
- Intractable HFrEF
- Fungal
- Recurrence of fever after 5 days of abx
- Persistent bacteremia
- Most cases of prosthetic valve
Empiric abx tx of
(a) native valve endocarditis
(b) prosthetic valve endocarditis
(a) Native valve endocarditis: cover strep viridans, other strep, then staph and enterococcus: vanc!
(then narrow to nafcillin)
(b) Prosthetic valve endocarditis: Staph epi, staph aureus: vanc, gent (used for synergy against enterococci), and cefepime (pseudomonal coverage)