MTB - Infectious Disease Flashcards
1
Q
Main body areas affected by staph.aureus infection
A
bone, heart, skin, joint
2
Q
DOC: sensitive staph. aureus (MSSA)
A
IV: oxacillin/nafcillin or cefazolin (first gen ceph)
oral: dicloxacillin or cephalexin (first gen ceph)
3
Q
DOC: MRSA - severe infection
A
vancomycin, linezolin, daptomycin, ceftaroline, tigecycline or telavancin
4
Q
televancin
A
vancomycin derivative w/ similar efficacy
5
Q
DOC: minor MRSA infection
A
TMP-SMX, clindamycin, doxycycline
6
Q
penicillin allergy (tx of staph aureus)
A
rash - cephalosporins safe
anaphylaxis - macrolides or clindamycin
if severe infection –> vancomycin, linezolid, daptomycin, telavancin
7
Q
which antibiotics are specific for streptococcus?
A
penicillin
ampicillin
amoxicillin
8
Q
which drug class works synergistically with other agents to tx. staph and strep?
A
aminoglycosides
9
Q
which drugs are excellent anti-anaerobic medications?
A
carbapenems
- also cover all strep and all MSSA
10
Q
tigecycline
A
MRSA
broad action against gram negative bacilli
11
Q
which drugs are excellent pneumococcal drugs?
A
levofloxacin, gemifloxacin, moxifloxacin
12
Q
Piperacillin/ Ticarcillin
A
cover gram negative rods, streptococci and anaerobes
13
Q
Only carbapenem that does not cover pseudomonas
A
ertapenam
14
Q
DOC: abdominal anaerobes
A
metronidazole
15
Q
only cephalosporins that cover anaerobes
A
cefoxitin, cefotetan
16
Q
which other drug classes have equal efficiacy to metronidazole for abdominal anaerobes
A
carbapenems
piperacillin
ticarcillin
17
Q
DOC: respiratory anaerobes (resp strep)
A
clindamycin
18
Q
medications with NO anaerobic coverage
A
aminoglycosides aztreonam FQs oxacillin/nafcillin all cephalosporins
19
Q
s/e: daptomycin
A
myopathy
20
Q
s/e: linezolid
A
low platelets
21
Q
s/e: imipenem
A
seizures
22
Q
s/e: vancomycin
A
red man syndrome –> red, flushed skin from histamine release due to rapid infusion rates. If this happens - slow the infusion rate down (no need to switch medications)
23
Q
Tx. herpes simplex, varicella zoster
A
acyclovir, valacyclovir, famciclovir
- all are equal in efficacy
24
Q
Tx. CMV
A
valganciclovir, ganciclovir, foscarnet
- equal in efficacy
- also cover HSV and VZV
25
best long term therapy for CMV retinitis
valganciclovir
26
s/e: valganciclovir and ganciclovir
bone marrow suppresion, neutropenia
27
s/e: foscarnet
renal toxicity
28
tx. infuenza A and B
oseltamavir and zanamavir (neuraminidase inhibitors)
29
Tx. Hepatitis C and RSV
ribavirin
30
Fluconazole - what does it cover?
candida (oral and vaginal), cryptococcus
31
Itraconazole
same as fluconazole but harder to use therefore, rarely initial therapy for anything
32
what drug covers all the candida species?
voriconazole
33
best agent against aspergillus?
voriconazole
34
s/e: voriconazole
visual disturbances
35
Echinocandins
caspofungin, micafungin, anidulafungin
36
What are the echinocandins useful for?
neutropenic fever patients (less mortality than amphotericin) but do NOT cover cryptococcus
37
a/e: echinocandins
none - affect/inhibit 1,3 glucan synthesis which does not exist in humans
38
what drug is effective against all candida, cryptococcus and aspergillus?
amphotericin
| - but basically there is a drug from above classes that is better or equal to with less side effects
39
s/e: amphotericin
renal toxicity
hypokalemia
metabolic acidosis
fever, shakes, chills
40
best initial test in suspected osteomyelitis?
Plain X-Ray
| although may take up to 2 weeks before changes are seen
41
best 2nd line test of osteomyelitis (i.e. negative XR but high clinical suspicion)
MRI
42
most accurate test for osteomyelitis?
bone biopsy and culture
43
earliest finding of osteomyelitis in XR
elevation of periosteum
44
best method for following response to therapy in osteomyelitis
ESR
| - if still elevated after 4-6 weeks of therapy, further treatment or surgical debridement may be necessary
45
MCC of osteomyelitis
continguous spread from overlying tissue
46
which test is more superior in osteomyelitis - MRI vs. bone scan?
MRI
| - they have equal sensitivity but MRI is far more specific
47
in osteomyelitis, is culturing the sinus tract or ulcer beneficial?
no - you should not do this
48
MCC osteomyelitis
staphylococcus
49
Tx. osteomyelitis
if sensitive: IV oxacillin or nafcillin for 4-6 weeks
if MRSA: vanco, linezolid or daptomycin
--> ORAL therapy is never appropriate
50
what must be done prior to initiating treatment for osteomyelitis?
bone biopsy/culture
| - no urgency in treating chronic osteomyelitis; obtain biospy, move clock forward and tx. what you find on culture
51
which type of osteomyelitis can be treated with oral drugs?
pseudomonas or salmonella osteomyelitis
52
patient comes in with itching and drainage from the external auditory canal; on physical exam, his ear is painful to manipulation - likely dx?
otitis externa
53
Dx. otitis externa
physical exam - no culture
54
Tx. otitis externa
1. topical antibiotics - ofloxacin or polymyxin/neomycin
2. add topical hydrocortisone (helps swelling/itching)
3. add acetic acid/water solution to reacidify
55
malignant otitis externa
osteomyelitis of the skull caused by pseudomonas in a patient with diabetes
56
dx. malignant otitis externa
tx. like osteomyelitis (XR, MRI, bone biopsy/culture)
57
tx. malignant otitis externa
surgical debridement
| antibiotics -> cipro, piperacillin, cefipime, carbapenem, aztreonam
58
most sensitive finding of otitis media
immobility of tympanic membrane
59
CF: otitis media
```
redness
bulging TM
decreased hearing
absent light reflex
decreased mobility of TM
```
60
best initial therapy otitis media
amoxicillin, 7-10 days
61
recurrent or persistent otitis media - management?
tympanocentesis and aspirate of TM for culture
62
CCS otitis media
advance clock 3 days - if infection not improving, switch amoxicillin to: amoxi-clav, cefdinir, ceftibuten, cefuroxime, cefprozil, cefpodoxime
63
best initial test: sinusitis
sinus XR
64
most accurate test: sinusitis
sinus aspirate for culture
65
when should you use antibiotics to treat sinusitis?
- fever and pain
- persistent sx. despite 7d of decongestants
- purulent nasal d/c
66
organisms that cause sinusitis (and otitis media)
Strep pneumo
H.flu
Moraxella catarrhalis
67
tx. sinusitis
first sx --> decongestants
| second --> amoxicillin + inhaled steroids
68
CF: pharyngitis
pain/sore throat
exudates
adenopathy
no cough/hoarseness
69
best initial test: pharyngitis
rapid strep test
70
tx. pharyngitis
amoxicillin/penicillin
71
tx. pharyngitis is allergic to penicillin
azithromycin or clarithromycin
72
next best step in patient that has influenza symptoms
viral antigen detection of nasopharyngeal swab
73
tx, influenza
oseltamavir or zanamavir - if pt presents w/in 48 hr onset of symptoms. If not - symptomatic therapy
74
Impetigo - organisms
strep pyogenes or staph aureus
75
what is impetigo?
superficial bacterial skin infection (epidermal layer)
76
CF: impetigo
weeping,"honey" crusting and oozing of the skin
77
tx. impetigo
topical mupirocin or retapamulin
| severe? oral dicloxacillin or cephalexin
78
community acquired MRSA impetigo
TMP/SMX
79
erysipelas
group A (pyogenes) strep infection; MC location - face
80
Dx. testing in erysipelas
order blood cultures on CCS but single best answer: start treatment
81
best initial therapy: erysipelas
oral dicloxacillin or cephalexin
| - if confirmed group A strep: penicillin VK
82
can erysipelas lead to rheumatic fever?
no - only glomerulonephritis
83
if there is cellulitis of the leg - what should you order?
LE Doppler to exclude a blood clot
84
MCC of cellulitis
staphylococcus aureus and streptococcus pyogenes
85
Tx. cellulitis (minor dz)
PO - dicloxacillin or cephalexin
86
Tx. cellulitis (severe dz)
oxacillin, nafcillin or cefazolin IV
87
T/F: does staph epidermidis cause skin infections - if true, which one?
false - normal skin flora
88
folliculitis
staph infection of hair follicle
| increasing in size: furuncle < carbuncle < boil < abscess
89
Tx. folliculitis/furuncles/carbuncles/boils
same as for cellulitis
PO - dicloxacillin or cephalexin
IV - oxacillin, nafcillin or cefazolin
90
best initial test for fungal infection of the skin
KOH preparation
91
Tx. fungal skin infection (no hair or nail involvement)
clotrimazole, miconazole, ketoconazole, nystatin, ciclopirox etc
92
Tx. fungal skin infection involving hair (scalp) or nails
PO anti-fungals --> terbenafine, itraconazole or griseofulvin
93
s/e terbinafine
elevated LFTs
94
urethral discharge is always a sign of....
urethritis
| +/- dysuric symptoms
95
Dx. testing urethritis
urethral swab - gram stain, WBC, culture, DNA probe
| NAAT
96
Tx. urethritis
two drugs - need to target gonorrhea and chlamydia
1. Ceftriaxon IM or PO Cefpodoxime
2. Azithromycin (single dose) or doxycycline 7d
97
patient is presenting with recurrent episodes of gonorrhea - what should they be tested for?
terminal complement deficiency
98
CF: disseminated gonorrhea
1. petechial skin rash
2. polyarticular disease
3. tenosynovitis
99
single best test for both gonorrhea or chlamydia
NAAT
| - blind swab for NAAT is just as accurate as speculum examination
100
Tx. cervicitis
exactly same as urethritis - cover for gonorrhea and chlamydia
1. Ceftriaxon IM or PO Cefpodoxime
2. Azithromycin (single dose) or doxycycline 7d
101
Pt presents with lower abdominal pain, tenderness, fever, dysuria, discharge and cervical motion tenderness - you suspect?
pelvic inflammatory disease
102
in PID - what test is a measure of severity of the disease?
WBC count - leukocytosis
103
best initial test in suspected PID
pregnancy test --> cervical culture --> DNA probe
104
most accurate test for dx of PID
laparoscopy --> only done for recurrent or persistent infection despite therapy
105
what kind of specimens can you use for NAAT?
men - urine
| women - blind vaginal swab
106
Outpatient Tx. PID
IM Ceftriaxone
| Doxycycline PO
107
Inpatient Tx. PID
IV Cefoxitin or Cefotetan
PO doxycycline
+/- Metronidazole
108
What abx are safe in pregnancy?
```
Penicillins
Cephalosporins
Aztreonam
Erythromycin
Azithromycin
```
109
Male pt presents with painful and tender testicle w/ normal position of testicle in scrotum - dx?
epididymo-orchitis
110
Tx. Epididymo-orchitis
< 35: Ceftriaxone + Doxy
| > 35: FQs
111
best initial test for chancroid
swab for gram stain (gram neg.) and culture (medium: Nairobi or Mueller-Hinton medium)
112
Tx. chancroid
single dose of either: IM Ceftriaxone or PO Azithromycin
113
CF: lymphogranuloma venereum
genital ulcer + large, tender LN that may develop suppurating, draining sinus tracts
114
Dx. lymphogranuloma venereum
serology for Chlamydia trachomatis
115
Tx. lymphogranuloma venereum
Doxycycline or Azithromycin
116
clear vesicular lesions on genitals - dx?
Herpes simplex virus
117
Next best step in management in pt who presents with multiple, clear vesicular lesions on genitals
Antivirals for 7-10d
| acyclovir, valacyclovir or famciclovir
118
which anti-viral is safe to use in pregnancy?
acyclovir
| - use in pregnancy if evidence of active lesions at 36 weeks
119
when would you do a Tzanck prep?
If patient has multiple vesicular genital lesions that have become ulcers
120
most accurate test for herpes
viral culture
121
acyclovir resistant herpes is treated with...
foscarnet
122
most accurate test in primary syphillis
darkfield microscopy
123
initial diagnostic test in primary syphillis
darkfield then VDRL/RPR
124
Tx. primary syphillis
single IM dose of penicillin
| penicillin allergy? doxycycline
125
Jarisch-Herxheimer reaction
patients being treated for primary syphillis may develop fever, headache and myalgia 24 hours after starting treatment; it is self-limiting; tx. w/ aspirin
126
CF: secondary syphillis
rash
mucous patches
alopecia areata
condyloma lata
127
initial dx. test in secondary syphillis
RPR and FTA
128
Tx. secondary syphyllis
single IM dose of penicillin
| doxy for pen-allergic pts
129
when do you do desensitization for tx. of a syphillis patient?
pregnancy
| neurosyphilis
130
initial dx. test in tertiary syphillis
RPR or FTA
| LP for neurosyphilis
131
Tx. tertiary syphilis
IV penicillin
| desensitize if pen-allergic
132
which test is more sensitive for neurosyphillis?
FTA > VDRL
133
granuloma inguinale
cause: Klebsiella granulomatis
| beefy red genital lesion that ulcerates
134
dx. granuloma inguinale
biopsy or touch prep
135
tx. granuloma inguinale
doxycycline, TMP/SMX or azithromycin
136
best initial test for cystitis
urinalysis
137
most accurate test for cystitis
urine culture
138
Tx. uncomplicated cystitis
PO TMP/SMX 3d; if E.coli resistance 20% - Cipro or Levofloxacin
139
Tx. complicated cystitis
7d TMP/SMX or Ciprofloxacin
140
what is complicated cystitis?
means there is an anatomic abnormality such as a stone, stricture, tumor or obstruction
141
who should get an USG if they have cystitis?
Men - it is unusual for a male patient to have a UTI in absence of anatomic abnormality
142
does everyone need a urine culture if you suspect cystitis?
No - clear symptoms + leukocytes on U/A --> go straight to treatment for 3d
143
Tx. outpatient pyelonephritis
Ciprofloxacin
144
Tx. inpatient pyelonephritis
ampicillin / gentamicin
145
nitrites on U/A are indicative of...
gram negative infection
146
a patient with diagnosed pyelonephritis is not responding to tx. with antibiotics after 7 days - what should you be considering?
pyelonephric abscess
147
Initial test in suspected pyelonephric abscess
CT scan or USG
148
Tx. pyelonephric abscess
quinolone and staph coverage (oxacillin/nafcillin)
149
prostatitis - best initial test
urinalysis
150
prostatitis - most accurate test
WBCs on U/A after prostate massage
151
Tx. prostatitis
ciprofloxacin - extended period of time
152
how many Duke's criteria do you need to dx. infectious endocarditis?
2 major
1 major + 3 minor
5 minor
153
Duke's Major Criteria (2)
1. Two positive blood cultures
| 2. Abnormal echo
154
Duke's Minor Criteria (5)
1. Fever > 38.5
2. Presence of RFs: IVDA, structural heart dz, prosthetic valves, dental procedures, positive history
3. vascular findings
4. immunologic findings
5. positive blood culture
155
Next best step in patient with fever + new or changing heart murmur
blood culture
| - if positive --> do an ECHO
156
best empiric therapy - infective endocarditis
Vancomycin + Gentamicin for 4-6 weeks
157
patient with infective endocarditis, blood cultures grow S. bovis - what test should be done?
colonoscopy
| - S.bovis is assoc. w/ colonic pathology
158
When do you consider valve replacement as a tx. for infective endocarditis?
1. anatomic defects
- valve rupture
- abscess
- prosthetic valves
2. fungal infections
3. embolic events ones started on abx
159
which cardiac defects need endocarditis prophylaxis?
1. prosthetic valves
2. unrepaired cyanotic heart dz
3. previous endocarditis
4. transplant recipients who develop valve dz
160
which procedures need endocarditis prophylaxis?
1. dental procedures that cause bleeding
2. respiratory tract surgery
3. surgery of infected skin
161
DOC: endocarditis prophylaxis
amoxicillin
162
when should you start HAART therapy?
1. CDC < 500
2. symptomatic regardless of CDC
3. pregnancy
4. needle stick scenario w/ HIV positive patient
163
S/E: NRTIs
lactic acidosis
164
S/E: protease inhibitors
hyperglycemia
| hyperlipidemia
165
S/E: NNRTIs
drowsiness
166
s/e: zidovudine
anemia
167
s/e: didanosine
pancreatitis
| peripheral neuropathy
168
s/e: stavudine
pancreatitis
| peripheral neuropathy
169
s/e: abacavir
rash
170
s/e: indinavir
kidney stones
171
post-exposure prophylaxis (HIV)
i.e. needlestick, mucosal exposure or unprotected sex
| Tx. HAART for one month
172
when do you start prophylaxis for PCP in HIV + and what do you use?
CDC < 200
Tx. TMP/SMX
- use atovaquone or dapsone if rash develops
173
MAC prophylaxis in HIV +
CDC < 50
| Tx. PO azithromycin, once weekly
174
what opportunistic infection presents w/ SOB, dry cough, hypoxia and increased LDH?
PCP
175
best initial test for PCP?
CXR (increased interstitial markings)
176
most accurate test for PCP?
broncheoalveolar lavage
177
best initial tx. for PCP?
IV TMP/SMX
if rash - use IV pentamidine
mild cases? IV atovaquone
178
Tx. severe PCP (pO2 < 70 and A-a gradient > 35)
IV TMP/SMX plus steroids
179
HIV+ pt presents with headache, nausea, vomiting and focal neuro findings - you suspect...and order what test first?
toxoplasmosis
| best initial test - head CT w/ contrast
180
Tx. toxoplasmosis
pyrimethamine and sulfadiazine for 2 weeks
| repeat head CT - if lesions smaller confirmation of toxo; if unchanged - biopsy needed
181
HIV pt with a CDC < 50 presents with blurry vision - what are you concerned about? best initial test?
CMV retinitis
| - performed dilated ophtho examination
182
Tx. CMV retinitis
ganciclovir or foscarnet
| maintenance therapy w/ valganciclovir is lifelong
183
HIV pt with CDC < 50 presents with fever and headache - which diagnostic test should you do? best initial vs. most accurate?
Lumbar puncture - increased lymphocytes
best initial = india ink stain
most accurate = cryptococcus antigen test
184
Tx. cryptococcus in HIV pt
Amphotericin followed by lifelong fluconazole
185
Patient with exposure to food and animal urine presents with fever, abdominal pain and muscles aches. He has jaundice. Dx?
Leptospirosis
186
Tx. leptospirosis
ceftriaxone or penicillin
187
A rabbit hunter presents to you with enlarged LNs, conjunctivitis and a large ulcer on his hand. Dx?
Tularemia
188
Dx test and Tx. of tularemia
Serology
| Tx. bentamicin or streptomycin
189
Management in patient with characteristic erythema migrans rash
Tx. with doxycycline w/o further testing
190
MC late manifestation of Lyme dz
joint dz
191
MC cardiac manifestation of Lyme dz
AV conduction block/defect
192
MC neurologic manifestation of Lyme dz
7th CN palsy
193
Tx, rash, joint dz or Bell's palsy as a complication of Lyme dz
PO doxycycline or amoxicillin
194
Tx. CNS or cardiac involvement as a result of Lyme dz
IV ceftriaxone
195
Patient presents to you after a camping trip with hemolytic anemia - dz?
Babesiosis
196
Dx. babesiosis
1. peripheral blood smear
- tetrads of intraerythrocytic ring forms
2. PCR
197
Tx. babesiosis
azithromycin and atovaquone
198
Patient comes back from a camping trip with elevated LFTs, thrombocytopenia and leukopenia - dz?
Ehrlichia
199
Dx. Ehrlichia
peripheral blood smear
| - morulae (inclusion bodies in WBCs)
200
Tx. ehrlichia
doxycycline
201
Tx. acute malaria
quinine + doxycycline
202
Prophylaxis for malaria
1. Weekly Mefloquine
| 2. Daily Atovaquone/Proguanil
203
S/e: mefloquine
neuropsychiatric s/e
sinus bradycardia
QT prolongation
204
branching gram positive filaments that are weakly acid fast
Nocardia
205
Tx. Nocardia
TMP/SMX
206
best initial test / most accurate test - Nocardia
best initial = CXR
| most accurate = culture
207
gram positive branching, filamentous bacteria that growns on anaerobic culture
Actinomyces
| - look for pt w/ history of dental or facial trauma
208
Tx. actinomyces
penicillin
209
Patient who was just bat cave exploring in Ohio presents with a viral-like syndrome along with oral ulcers and splenomegaly - dx?
histoplasmosis
210
best initial test - histoplasmosis
urine antigen test
211
most accurate test - histoplasmosis
biopsy + culture
212
Tx histoplasmosis
acute pulmonary dz - no tx
| disseminated dz - amphotericin
213
Acute resp illness that causes joint pain and erythema nodosum - dry areas like Arizona
Coccidioidomycosis
214
Tx. coccidioidomycosis
itraconazole
215
Acute pulm dz that may have bone lesions; Broad budding yeast from the rural southeast
Blastomycosis
216
Tx. blastomycosis
amphotericin or itraconazole
217
how can you identify traumatic LP?
RBC > 6000/mm3 without xanthochromia
| elevated WBC - 1:750-1000 RBCs
218
CSF WBC:RBC ratio < 0.01
100% negative predictive value for meningitis`
219
treatment of pregnant woman with chlamydia
erythromycin base 500 mg QID for 7d
| amoxicillin 500 mg PO TID for 7d
220
chemoprophylaxis of meningococcal meningitis
1. Rifampin 600 mg PO bid for 4 doses
| 2. Ciprofloxacin 500 mg PO single dose
221
Which drug(s) does Rifampin interfere with?
steroids ex. OCP (decreases levels) - use an alternative
222
post-exposure prophylaxis of health care workers exposed to contagious patient with TB
1. immediate placement of PPD
- baseline immunologic status
2. repeat PPD test after three months
- check for any changes due to recent exposure
223
tick paralysis
progressive ascending paralysis that occurs over matter of hours/days; fever and pupillary abnormalities are uncommon
224
management: tick paralysis
removal of tick - substantial improvement in paresis w/in hours
225
ecythema gangrenosum
lesions of skin/mucous membranes that rapidly worsen and evolve into nodular patches marked by hemorrhage, ulceration and necrosis; caused by pseudomonas invasion of media and adventitia of arteries and veins followed by ischemic necrosis
226
Tx. pseudomonas bacteremia
1. aminoglycoside (tobramycin, amikacin) + piperacillin
| 2. antipseudomonal cephalosporin (ceftazidime, cefipime)
227
tx. herpes zoster
oral acyclovir, 800 mg 5x/day
steroids may help accelerate healing time but should not be used in patients with other comorbidities (diabeter, osteoporosis, HTN, glaucoma)
228
do patients with herpes zoster need to be placed in isolation?
if immunocompetent with localized case - no!
| contact precautions recommended for hospitalized patients, pts with disseminated zoster or immunocompromised pts
229
tx. postherpetic neuralgia
TCAs (desimipramine, amitriptyline)
topical capsaicin
gabapentin
long acting oxycodone
230
cause of HIV lipodystrophy
dyslipidemia
| insulin resistance
