Infectious Disease Flashcards
Things that dont grow on culture?
pneumocystis, syphilis.
Bacteria covered by amoxicillin
HELPS
H.flu E.coli Listeria Proteus Salmonella
only cephalosporin that will cover MRSA?
ceftaroline
drugs that cover MRSA?
vanc, dapto, ceftaroline, linezolid
what 3 organisms are resistant to all forms of cephalosporins?
Listeria, MRSA, Enterococcus
why avoid ceftriaone in neonates?
impaired biliary metabolism
what cephalosporin covers pseudomonas?
ceftazidime
carbapenams are highly active against?
gram negative bacilli
side effects of quinolones?
bone growth abnormalities
tendonitis and achilles tendon rupture
moxifloxacin can be used as a single agent against?
diverticulitis/GI infections (vs other quinolones that need to be paired with metronidazole)
what antibiotic can lead to Fanconi syndome (type II RTA)
doxycycline
minor MRSA infection of skin are treated with?
TMP/SMX
Clinda
Doxy
Linezolid
all of the ______ abx cover anearobes with equal efficacy to metronidazole?
lactam/beta-lactamase inhibitors
meningitis in those with recent neurosurgery?
staph aureus
meningitis with CD 4<100 ?
cryptococcus
camper/hiker meningitis?
lyme
what will cell count look like on LP for crypto, lyme, rickettsia, TB, viral?
10s-100s. lymphocytes
How can you differentiate TB from others with protein level on LP?
TB protein- markedly elevated
Answer head CT before LP whenever these signs are present??
papilledema, seizure, focal neuro abnml, confusion, blurred disc
if contraindication to immediate LP, what do you do first?
abx
when are bacterial antigen tests indicated in terms of meningitis?
patient received abx prior to LP and culture might be falsely negative
most accurate test for TB meningitis?
acid fast stain and culture on 3 high volume LPs with centrifuge to concentrate organisms due to high protein load
test for lyme and rickettsia meningitis?
serologic testing- ELISA, western blot, PCR
Most accurate test for crypto in descending order?
culture > antigen > india ink
How to treat meningitis if 1,000 of PMNs and on CSF?
ceftriaxone, vanc, steroids. add amp if immunocompromised.
(steroids- dexamethasone)- has only been shown to lower mortality in S. pneumoniae infection but still give them because we wont have culture!
additional treatment considerations for neisseria meningitidis patients?
rifampin, cipro, ceftriaxone for close contacts (those with major contact- household, kissing, sharing things- not classmates)
respiratory isolation
most common neuro deficit in untreated bacterial meningitis?
VIII CN deficit or deafness
Most common cause of encephalitis?
HSV
most accurate diagnostic test for HSV?
PCR of CSF
what is used for acyclovir resistant herpes meningitis?
Foscarnet
what should you do if a patient with HSV enceph on acyclovir gets a creatinine bump?
lower acyclovir dose and hydrate!
(foscarnet is more toxic to kidney)
valacyclovir and famciclovir are PO and not good enough for Enceph
when is tympanocentesis indicated for otitis media
multiple recurrences or no response to multiple abx
what is never the answer to “most accurate test” in ID questions?
Radiology!
most accurate test for sinus infection?
sinus biopsy or aspirate
should you ever culture nasal discharge for sinusitis?
NO!! (most common wrong answer)
What do you use for strep pharyngitis is allergy to penicillin is anaphylaxis?
clinda or a macrolide
Association with Yersinia infectious diarrhea?
Yersinia has a high association for iron (hemochromatosis- blood transfusions)
Best initial test for infectious diarrhea?
blood and or fecal leukocytes
what is more sensitive- stool lactoferrin or stool leukocytes?
stool lactoferrin (choose this if its an answer choice)
scombroid? found in? treat with?
most rapid onset of non-bloody diarrhea. wheezing, flushing, rash, found in fish, treat with antihistamine
Giardia treatment?
metronidazole, tinidazole
cryptosporidiosis tx?
treat AIDS, nitazoxanide
Hep D exists exclusively in those with?
Hep B
Which Hep rarely presents with acute infection- but is found incidentally on blood tests
C
What abnormal lab test correlates best with increased likelihood of mortality?
Prothrombin Time
what lab marker becomes abnormal first in hep B?
Surface antigen
e-antigen for Hep B indicates a high level of?
DNA polymerase activity
what lab marker indicates that a patient is no longer at risk for transmiting hep B infection?
No surface antigen found
what lab marker is best indication for needed treatment with antiviral meds for hep B?
e-antigen
best indicator that a pregnant woman will transmit hep B to her child?
- Hep B viral load (more precise)
and
e-antigen (DNA polymerase)
chronicity of hep B is defined as?
persistence of surface antigen > 6 months
adverse effects of interferon
arthralgia/myalgia
leukopenia and thrombocytopenia
depression and flu
(interferon is never the first right choice because it an injection and SE)
Ribavirin causes?
anemia
should you test for Hep C based on risk factors?
NO
What is the only acute viral hepatitis infection that needs treatment?
Hep C
What predicts response to therapy in Hep C?
genotype
how to differentiate urethritis and cystitis?
both have urinary frequency and burning. cystitis does not have urethral discharge
what is the most accurate test for PID?
laparoscopy (although you diagnose with cervical swab)
What is the most sensitive test of CSF for neurosyphilis?
FTA!!
does a negative FTA of CSF exclude neurosyphilis?
yes
Does a negatie VDRL/RPR of CSF exclude syphilis?
NOoo
Titers of VDRL or RPR are reliable at greater than ___?
1:8
What can give you a false positive VDRL/RPR?
infection, older age, IV drug use, AIDS, malaria, antiphospholipid, endocarditis
Jarisch-Herxheimer rxn?
fever and worse symptoms after treatment for syphilis
Give ASA and antipyretics- it will pass
If patients with tertiary syphilis are allergic to penicillin what do you do? exception?
desensitize. Not in pregnant women!
how to diagnose condyloma accuminata?
PE- physical appearance
Imiquimod and pdophyllin (trichloroacetic acid) are both used for?)
HPV warts
how do you treat crabs?
permethrin
best initial therapy for pyelo?
ceftriaxone
what do you treat pyelo with until urine culture results are known?
amp and gent
diagnostic yield of a urine culture for prostatitis is greatly increased with?
prostate massage
how to treat prostatitis?
6-8 weeks of ciprofloxacin or TMP/SMX
fever and heart murmur =
endocarditis
Man comes in to ED with fever and murmur and blood cultures grow Clostridium Septicum. What should you do next?
Colonoscopy- Clostridium Septicum has more of an association with colon cancer than Strep Bovis
Best initial empiric therapy for endocarditis?
Vanc and Gent
treatment of viridans strep endocarditis?
ceftriaxone for 4 weeks
treatment of staph aureus endocarditis (sensitive)
oxacillin, naf, cefazolin
fungal endocarditis treatment?
amphotericin and valve replacement
staph epidermidis or resistant staph aureus treatment for endocarditis?
Vancomycin
Treatment for enterococcus endocarditis?
amp and gent
when is surgery the answer for endocarditis management?
CHF from ruptured valve or cordae tendineae, prosthetic valves, fungal endo, abscess, AV block, recurrent emboli while on abx
What drug should you add for a prosthetic valve endocarditis infected with Staph?
Rifampin
most common cause of culture negative endocarditis?
Coxiella
single strongest indication for surgery with endocarditis is?
valve rupture with CHF
How do you treat the HACEK organisms?
Ceftriaxone
Best management for endocarditis prophylaxis?
amoxicillin prior to procedure
If the patient is penicillin allergic- what is the best prophylaxis for endocarditis?
clindamycin, azithromycin, clarithromycin
Is valvular heart disease- including mitral valve prolapse a reason to give prophylaxis for endocarditis?
No
When is a single dose of doxy indicated for tick bite?
-If within 72 hours of tick bite- you can identify ixodes scapularis clearly as identifying cause, tick is attached for longer than 24 hours, engorged tick on skin, endemic area
how do you diagnose HIV in babies?
viral load. ELISA unreliable because of maternal antibodies.
what antiretroviral is contraindicated in pregnancy?
efavirenz
Management of anaphylactic reaction?
epinephrine, antihistamines s(H1-blocker) and ranitidine (H2 blocker), Glucocorticoids- methylprednisolone or hydrocortisone, emergent airway protection if needed
Hereditary angioedema does not respond to what management?
glucocorticoids
best test for angioedema diagnosis?
C2 and C4. Deficiency of C1 esterase inhibitor
Specific therapy for angioedema?
FFP or Ecallantide
Long term with androgens (danazol or stanazol)
CVID gives a marked increase in a patients risk of?
lymphoma
recurrent skin infections with staph indicates what syndrome?
Hyper IgE
only definitive treatment for Wiskott-Aldrich syndrome?
bone marrow transplant
