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Flashcards in MTB - Infectious Disease Deck (230):
1

Main body areas affected by staph.aureus infection

bone, heart, skin, joint

2

DOC: sensitive staph. aureus (MSSA)

IV: oxacillin/nafcillin or cefazolin (first gen ceph)
oral: dicloxacillin or cephalexin (first gen ceph)

3

DOC: MRSA - severe infection

vancomycin, linezolin, daptomycin, ceftaroline, tigecycline or telavancin

4

televancin

vancomycin derivative w/ similar efficacy

5

DOC: minor MRSA infection

TMP-SMX, clindamycin, doxycycline

6

penicillin allergy (tx of staph aureus)

rash - cephalosporins safe
anaphylaxis - macrolides or clindamycin
if severe infection --> vancomycin, linezolid, daptomycin, telavancin

7

which antibiotics are specific for streptococcus?

penicillin
ampicillin
amoxicillin

8

which drug class works synergistically with other agents to tx. staph and strep?

aminoglycosides

9

which drugs are excellent anti-anaerobic medications?

carbapenems
- also cover all strep and all MSSA

10

tigecycline

MRSA
broad action against gram negative bacilli

11

which drugs are excellent pneumococcal drugs?

levofloxacin, gemifloxacin, moxifloxacin

12

Piperacillin/ Ticarcillin

cover gram negative rods, streptococci and anaerobes

13

Only carbapenem that does not cover pseudomonas

ertapenam

14

DOC: abdominal anaerobes

metronidazole

15

only cephalosporins that cover anaerobes

cefoxitin, cefotetan

16

which other drug classes have equal efficiacy to metronidazole for abdominal anaerobes

carbapenems
piperacillin
ticarcillin

17

DOC: respiratory anaerobes (resp strep)

clindamycin

18

medications with NO anaerobic coverage

aminoglycosides
aztreonam
FQs
oxacillin/nafcillin
all cephalosporins

19

s/e: daptomycin

myopathy

20

s/e: linezolid

low platelets

21

s/e: imipenem

seizures

22

s/e: vancomycin

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

Tx. herpes simplex, varicella zoster

acyclovir, valacyclovir, famciclovir
- all are equal in efficacy

24

Tx. CMV

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