Infectious Diseases Flashcards
MSSA IV antibiotics
oxacillin/nafcillin or cefazolin (1st gen)
MSSA oral antibiotics
dicloxacillin or cephalexin (1st gen)
MRSA severe antibiotics
linezolid, vancomycin, daptomycin, ceftaroline, tigecycline, telavancin
side effect of linezolid
thrombocytopenia
side effect of daptomycin
myopathy, rise in CPK
minor MRSA antibiotics
TMP/SMX, doxycyline, clindamycin
rash with penicillin
cephalosporin
anaphylaxis with penicillin
Macrolide (azithromycin, clarithromycin), clindamycin, TMP/SMX
Streptococcus specific antibiotics
penicillin, ampicillin, amoxicillin
cephalosporin against gram neg rods
cefepime, Ceftazidime
penicillins against gram neg rods
piperacillin, ticarcillin
monobactam against gram neg rods
aztreonam
quinolones against gram neg rods
ciprofloxacin, levofloxacin, moxifloxacin, gemifloxacin
aminoglycosides against gram neg rods
gentamycin, tobramycin, amikacin
carbapenems against gram neg rods
imipenems, meropenem, ertapenem, doripenem
ertapenem exception
doesn’t cover Pseudomonas
alternative antibiotics equal in efficacy to metronidazole for abdominal aerobes
piperacillin, ticaracillin, carbapenem
only cephalosporins covering anaerobes
cefoxitin and cefotetan
best drug to cover anaerobic strep
clindamycin
antibiotics with no anaerobic coverage
aminoglycosides, aztreonam, fluoroquinolones, oxacillin/nafcillin, and all cephalosporins except cefoxitin and cefotetans
gemifloxacin
quinolone for pneumonia
antibiotic that has excellent anaerobic coverage, cover streptococci and all MSSA
carbapenem
antibiotics work synergistically with other agents to treat staph and strep
aminoglycosides
covers MRSA and broadly active against gram neg rods
Tigecycline
antiviral against HSV and varicella
acyclovir, valacyclovir, famciclovir
antiviral against CMV
valganciclovir, ganciclovir, foscarnet
best long term therapy for CMV retinitis
valganciclovir
valganciclovir and ganciclovir adverse effects
neutropenia and bone marrow suppress
foscarnet adverse effects
renal toxicity
ribavirin used for antiviral treatment of what
hep c, RSV
lamivudine, interferon, adefovir, tenovir, entecavir, telbivudine is antiviral treatment of what
chronic hep b
treat candida (not candida krusei or candida glabrata), cryptococcus, oral and vaginal candidiasis
fluconazole
best agent against aspergillus
voriconazole; also covers all candida
SE of voriconazole
visual disturbance
neutropenic patient with fungal infection give what anti fungal
echinocandins (caspofungin, micafungin, anidulafungin)
what does echinocandins (caspofungin, micafungin, anidulafungin) not cover
cryptococcus
adverse effects of echinocandins
no adverse effect; echinocandins have no significant human toxicity bc they affect/inhibit 1,3 glucan synthesis step, which does not exist in humans
for candida which anti fungal is best
fluconazole and amphotericin is = in efficacy, but has much fewer adverse effects
adverse effects of amphotericin
renal toxicity (increased creatine), hypokalemia, mrtabolic acidosis, fever, chills, shakes
best initial and second line test and most accurate test
best initial: x-ray, second line: MRI, most accurate: bone biopsy and culture
how long does it take for abnormal X-ray from osteomyelitis
2 weeks; must lose more than 50% of calcium content of the bone before the x-ray becomes abnormal
involucrum and sequestrum on bone X-ray
abnormal new bone in the periosteum
earliest finding of osteomyelitis
periosteal elevation
best method of following a response to therapy
follow sedimentation rate
osteomyelitis most commonly caused by
direct contiguous spread from overlying tissue
how long to treat patient with no fever and normal wbc with osteomyelitis
if ESR is markedly elevated after 4-6 weeks of therapy, further treatment and possible surgical debridement is necessary
most common cause of osteomyelitis, how to treat
staph
IV only for 4-6 weeks
MSSA: oxacillin or nafcillin
MRSA: vancomycin, linezolid, or daptomycin
how to treat osteomyelitis for gram neg bacilli (salmonella, pseudomonas)
can treat with oral abc
confirm gram neg with bone biopsy
no urgency for treating chronic osteomyelitis; biopsy –> move clock forward –> treat what you find on culture
treatment of otitis externa
1) topical abx: ofloxacin or polymyxin/neomycin
2) hydrocortisone to reduce swelling and itching
3) acetic acid to reacidify the ear and eliminate the infection
malignant otitis externa
osteomyelitis of the skull from Pseudomonas in a patient with diabetes, can lead to brain abscess and destruction of the skull
treatment malignant otitis externa
treat like osteomyelitis: x-ray, mri, biopsy/culture; treat with surgical debridement and abx against Pseudomonas such as ciprofloxacin, piperacillin, cefepime, carbapenem, axtreonam
treatment otitis media
amoxicillin for 7-10 days; tympanocentesis and aspirate of tympanic membrane for culture
patient with otitis media no improvement with amoxicillin after 3 days
switch amoxicillin to amoxicillin-clavulante, cefdinir, ceftibuten, cefuroxime, cefprozil, cefpodoxime
most causes of sinusitis
viral some bacterial
bacterial causes of sinusitis
Strep pneumo, H. influenzae, Moraxella catarrhalis
best initial test, most accurate test for sinusitis
best initial test is x-ray, most accurate test is sinus aspirate for culture (more accurate than ct or mri)
treatment for sinusitis
inhaled steroids, amoxicillin 7-10 days if fever and pain or persistent symptoms despite 7 days of decongestants, purulent nasal discharge
hallmark streptococcal pharyngitis symptom
no cough/hoarseness, pain/sore throat, lymphadenopathy, exudate
treatment of strep throat
penicillin or amoxiciliin; if penicillin allergy than use azithromycin or clarithromycin
oseltamivir and zanamivir works against
influenza A and B within 48 hours of symptom onset
amantadine and rimantadine works against
influenza A only
influenza symptoms
cough, headache, myalgias, fever, sore throat, feelings of tiredness
diagnostic testing for influenza
viral antigen detection testing of nasopharyngeal swab
strongest indicators for influenza vaccination
CHF, COPD, dialysis patients, steroid use, health care workers, everyone >50
treatment of impetigo
topical mupirocin or retapamulin (mupirocin has greater activity against MRSA, bacitracin has less efficacy as a single agent)
community acquired MRSA impetigo
TMP/SMZ; clindamycin is sometimes useful
treatment of severe impetigo
oral dicloxacillin or cephalexin
treatment of impetigo with penicillin allergy: rash? anaphylaxis? sever infection with anaphylaxis?
rash: cephalosporin; anaphylaxis: clindamycin, doxycycline, linezolid; severe infection with anaphylaxis: vancomycin, telavancin, linezolid, daptomycin
erysipelas
group A pyogenes strep infection of the skin; skin is bright red and hot dilation of capillaries of the dermis; usually on face
management of erysipelas
on CCS order blood cultures (may be positive) on multiple choice go straight to treatment
treatment of erysipelas
oral dicloxacillin or cephalexin; if organism confirmed group A beta hemolytic strep may treat with penicillin VK
cause of cellulitis
strep pyogenes = straph aurea
treatment of cellulitis: minor, severe
minor disease: dicloxacillin or cephalexin orally; severe disease: oxacillin, nafcillin, or cefazolin IV
case of leg cellulitis
order doppler to rule out
folliculitis<abscess
skin infections caused by strep –> glomerulonephritis not rheumatic fever
best initial test of fungal infection of nail and skin
KOH prep
treatment of fungal infection of nail and skin
topical if no hair involvement: clotrimaxole, miconaxole, ketoconazole, econazole, terconazole, nystatin, or ciclopirox
oral for scalp (tinea capitis) or nail (onychomycosis): terbinafine, itraconazole, griseofulvin
side effect of terbinafine
causes increased LFTs
side effect of griseofulvin (tinea capitis)
has less efficacy than either terbinafine of itraconazole
discharge without dysuria..
dysuria without discharge..
discharge without dysuria still urethritis
dysuria without discharge does not necessarily have urethritis
treatment for urethritis
2 meds: gonorrhea and chlamydia
diagnostic testing for urethritis
1) urethral swab for gram stain, wbc cound, culture, dna probe
2) NAAT nucleic acid amplification test
gonorrhea meds
ceftriaxone IM, cefpodoxime oral, ciprofloxacin oral (2nd line)
chlamydia meds
azithromycin (single dose), doxycycline (for a week)
how to treat pregnant women with urethritis
1) IM ceftriaxone 2) azithromycin
diagnostic testing for PID
1) pregnancy test (r/o ectopic) 2) then cervical culture and DNA probe for chlamydia and gonorrhea
most accurate test for PID
laparoscopy; only done for recurrent or persistent infection despite therapy or for cases where diagnosis is not clear
inpatient treatment for PID
IV cefoxitin or cefotetan or metronidazole + doxycyline
outpatient treatment for PID
Ceftriaxone IM + doxycycline oral
antibiotics safe in pregnancy
penicillin, cephalosporin, aztreonam, erthromycin, azithromycin
painful and tender testicle with normal position in scrotum
epididymo-orchitis
treatment of epididymo-orchitis
35 years: fluoroquinolones
painful genital ulcer, best initial test?
chancroid (Haemophils ducreyi)
best initial test is swab for gram stain (gram neg coccobacilli) and culture (Nairobi medium or Mueller-Hinton agar)
treatment of chancroid
single IM shot of ceftriaxone or single oral dose of azithromycin
large tender nodes in genital area, how to diagnose? treat?
Lymphogranuloma venereum, may develop a suppurating draining sinus tract
diagnose with serology for Chlamydia trachoma tis
treat with aspirate the bubo and then doxycycline azithromycin
patient presents with enlarged adenopathy in inguinal area and multiple clear vesicles on his penis, what’s the next step in management?
treat with acyclovir, valacyclovir, or famciclovir for 7-10 days; when clear vesicles are present there is no need to do specific diagnostic test for herpes, if roof come off of vesicles and lesion becomes an ulcer of unclear etiology, the the best initial diagnostic test is Tzanck prep
most accurate test for herpes
viral culture
tx of herpes in pregnancy
acyclovir is safe in pregnancy; use if there is evidence of active lesions at 36 weeks
painless, firm genital lesion, painless inguinal adenopathy
syphilis
most accurate test in primary syphilis
darkfield microscopy (more sensitive than VDRL or RPR)
symptoms of primary syphilis
chancre, adenopathy
initial diagnostic test for primary syphilis
darkfield, then VDLR/RPR
treatment for primary syphilis
single IM shot of penicillin; if allergic use doxycycline
how to treat Jarish-Herxheimer treaction
fever, headache, myalgia developing 24 hours after treatment for early stage syphilis , release of pyrogens from dying treponemal –> treat with aspirin and continue treatment
symptoms of secondary syphilis
rash, mucous patch, alopecia areata, condyloma lata
initial test for secondary syphilis
RPR and FTA
treatment for secondary syphilis
single IM shot of penicillin, doxycycline if penicillin allergy
neurological involvement of tertiary syphilis
tabes dorsalis, argyll-robertson pupil, general paresis
initial diagnostic test for tertiary syphilis
RPR and FTA, lumbar puncture for neurosyphilis (test CSF with VDRL and FTA; CSF VDRL is only 50% sensitive)
treatment of tertiary syphilis
IV penicillin; if allergic DESENSITIZE
rare beefy red genital that ulcerates
granuloma inguinale
diagnostic test for granuloma inguinale
biopsy or touch prep, klebsiella granulomatis
treatment for granuloma inguinale
doxycycline, tmp/smx, or azithromycin
pediculosis vs. scabies
pediculosis is larger, in hair-bearing areas, such as pubic area or axilla, visible on surface
scabies is small, burrows in web spaces, scrape and magnify
treatment of scabies
permethrin, lindane, or ivermectin
treatment of pediculosis
permethrin, pyrethrins, or lindane
how are warts diagnosed?
by how they look
what is imiquimod?
immunostimulamt that leads to sloughing off of wart
what is podophyllin?
melts warts
complicated cystitis treatment
7 days of tmp/smx or ciprofloxacin
uncomplicated cystitis treatment
3 days of tmp/smx orally if e.coli resistance low in that area; if resistance is >20% than use ciprofloxacin
abx for pyelonephritis…outpatient? inpatient?
outpatient ciprofloxacin; inpatient use ampicillin/gentamycin
radiology testing and UTI
cystitis and pyelonephritis is diagnosed by radiologic study (sonogram or CT). sonogram and CT used to determine the etiology of UTI.
pyelonephritis patient not responding to treatment after 5-7 days, still febrile, abc on UA
perinephritic abscess; perform sonogram or CT of kidneys to find the collection; biopsy to determine microbiologic diagnosis
treatment of perinephritic absess?
quinolone and add staphylococcal coverage such as oxacillin or nafcillin, b/c tx with abc for gram neg organism preferentially selects out for staphylococci
best initial test for prostatitis
UA
most accurat test
Urine WBC after prostate massage
treatment of prostatitis
ciprofloxacin for extended period of time
duke’s criteria
diagnosis of infective endocarditis (2 major, 1 major + 3 minor, or 5 minor criteria)
clinical suspicion for infective endocarditis neg cultures
HACEK organisms
fever + new murmur or change in murmur, next step
perform blood cultures
blood cultures positive in patient with fever + new murmur
perform EKG look for vegetations endocarditis
treatment for endocarditis
empiric therapy with vancomycin and gentimicin (covers MRSA, S. Aureus, viridans Streptococcus)
treatment is 4-6 weeks
indications for surgery (valve replacement with infective endocarditis)
anatomic defects
- valve rupture
- abscess
- prosthetic valve
- fungal endocarditis
- embolic events once already started on antibiotics
procedures that require abx prophylaxis for endocarditis
dental procedures that cause bleeding, respiratory tract surgery, surgery of infected skin
only cardiac defects that need prophylaxis
prosthetic valves, unrepaired cyanotic heart disease, previous endocarditis, transplant recipient who developed valve disease
side effect of NRTI
lactic acidosis (meds ending with -dine or -sine, -bine, -avir
side effect of protease inhibitor
hyperglycemia, hyperlipidemia (meds ending with -navir)
NNRTI side effects
drowsiness (efavirenz)
side effect of indinavir
kidney stones
side effect of zidovudine
anemia
side effect of didanosine
pancreatitis and peripheral neuropathy
side effect of abacavir
rash
side effect of stavudine
pancreatitis and neuropathy
needle stick injury with anyone exposed to HIV positive blood
HAART for a month
HIV perinatal transmission prevention
CD4500 start HAART immediately better than during 2nd and 3rd
when to start prophylaxis for PCP? with what?
CD4t use with G6PD deficiency)
MAI prophylaxis when and what?
when CD <50, use azithromycin one a week orally
how does PCP present
dry cough, SOB, hypoxia, increased LDH
best initial test for PCP
chest X-ray: will show increased interstitial markings bilaterally
most accurate test for PCP
bronchoalveolar lavage
treatment of PCP
IV tmp/smx
treating PCP develop rash
rash with tmp/smx; use IV pentamidine
treatment of mild PCP
atovaquone
if PCP is severe pO235
give steroids
best initial test for toxo
head CT with contrast
confirmatory test for toxo
treat with pyrimethamine and sulfadiazine for two weeks, repeat CT scan, if lesions are smaller, then this confirmatory, if lesions are unchanged –> do brain biopsy, most likely lymphoma
treatment of toxo
pyrimethamine and sulfadiazine for 2 weeks
how does CMV present
blurry vision in HIV patient with CD 4<50
how to diagnose CMV
dilated opthalmologic examination; diagnosed by appearance on dilated ophthalmologic examination
how does cryptococcus present in HIV patient
HIV and <50 CD4 cells with fever and headache, sometimes neck stiffness and photophoia
suspect cryptococcus, next step
lumbar puncture –look for increase level of lymphocytes in CSF
best initial test for cryptococcus
India ink tain
most accurate test for cryptococcus
cryptococcal antigen test
treatment of cryptococcus
treat initially with amphotericin followed by fluconazole (echinocandins -caspofungin do not cover cryptococcus)
best initial test for PML
head CT or MRI
how does PML present
HIV patient CD4<50 with focal neurological abnormalities
treatment of PML
treat with HAART, when CD4 rises, PML will resolve
MAI presentation
HIV patient, CD4<50, wasting with weight loss, fever, fatigue, anemia (invasion of the bone marrow), increased ALP and GGTP with normal bilirubin
diagnostic testing for MAI
bone marrow is more sensitive, liver biopsy is most sensitive, blood culture least sensitive
treatment of MAI
Clarithroymycin and ethambutol, prophylaxis with azithromycin
treatment of leptospirosis
diagnose with serology, treat with ceftriaxone or penicillin
animal exposure + jaundice + renal
leptospirosis (fever, abdominal pain, muscle ache)
ulcer at site of contact and enlarged lymph nodes, conjunctivitis, contact with small furry animal
tularemia
tx for tularemia
bentamicin or streptomycin
culture is dangerous for lab personnel, causes severe pneumonia
tularemia
treatment of cysticerosis
albendazole
CT scan of head shows thin-walled cysts, calcified
cysticerosis
how to diagnose leptospirosis
diagnose with serology
treatment of lyme disease with rash, joint, bell’s palsy
oral doxycylien or amoxicillin
lyme disease with CNS or cardiac involvement
IV ceftriaxone
babesiosis transmitted by
ixodes tick
treatment of babesiosis
azithromycin or atovaquone
what is ehrlichia transmitted by
ixodes tick
how does ehrilichia present
NO RASH; elevated LFTs (ALT, AST), thrombocytopenia, leukopenia
how to treat ehrlichia
doxycycline
most common late manifestation of lyme disease
joint problems
diagnostic test for ehrlichia
peripheral blood smear looking for morulae (inclusion bodies in white cells) or PCR
hemolysis and GI complaints
malaria
how to treat acute malaria
quinine and doxycycline
prophylaxis for malaria
mefloquine (weekly) or atovaquone/proguanil
side effect of mefloquine
neuropsychiatric side effects, sinus bradycardia, and QT prolongation
nocardia affects who and where?
immunocompromised (leukemia, lymphoma, steroid use, HIV), may disseminate to any organ but skin and brain most common
best initial test, most accurate test for nocardia?
best initial test: chest x-ray
most accurate test: culture
actinomyces affects who?
normal immune system, history of facial or dental trauma, actinomyces is part of normal mouth flora
how to diagnose actinomyces
gram stain and confirm with anaerobic culture
treatment of actinomyces
penicillin
presents as a viral syndrome, physical exam shows palate and oral ulcers and splenomegaly
histoplasmosis (disseminated disease can cause pancytopenia) anything TB can do, histoplasmosis can do
best diagnostic test for histoplasmosis
histoplasmosis urine antigen
most accurate test for histoplasmosis
biopsy with culture
treatment of acute pulmonary histoplasmosis disease
no therapy
treatment of disseminated histoplasmosis
amphotericin
where is histoplasmosis found?
ohio and mississippi river valleys
where is coccidiodomycosis found?
dry areas like arizona
presentation of coccidiodomycosis
respiratory disease with joint pain and erythema nodosum
treatment of coccidiodomycosis
itraconazole
treatment of coccidiodomycosis
itraconazole
broad budding yeast
blastomycosis
where does blastomycosis occur?
rural southeast
pulmonary disease with bone lesions
blastomycosis
treatment of blastomycosis?
amphotericin or itraconazole
branching, gram positive filaments that are weakly acid fast
nocardia
