COMMON ID
SYNDROMES
MARCH 2014
OBJECTIVES
• Identifying the bug
• Choosing the antibiotics
• Empiric coverage for common ID scenarios
BASICS
• Try to collect cultures before starting antibiotics
• Renally dose antibiotics (esp Vanco, levaquin)
• Call the ID fellow for approval when required
• Use Sanford Guide and hospital antibiograms
• Sanford Guide now has a mobile app
• Epocrates app also has useful guides
Consider
your bugs!
What are
you treating
or covering
empirically?
COMMON ID SYNDROMES
(COVERED IN THIS LECTURE)
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Bacterial Meningitis
Infective Endocarditis
Clostridium Difficile
Urinary Tract Infections
Cellulitis
CAP & HCAP (covered elsewhere)
BACTERIAL MENINGITIS
• Common causes of meningitis:
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S. pneumoniae (30-50%)
Neisseria meningitidis (10-35%)
Listeria (2-11%)
Other less common include:
• Gram-negative; Streptococci; Staphylococci; H. influenzae
• Diagnosis: LP
• Gram stain, C&S, cell count w/ diff, protein, and glucose
• Empiric treatment for Suspected Bacterial Meningitis
• 3rd gen cephalosporin (ceftriaxone or cefotaxime), PLUS
• Vancomycin, +/• Ampicillin (if at risk for Listeria: age >60 or neonate)
INFECTIVE ENDOCARDITIS
• Obtain 3 sets of blood cultures
• Diagnosis: Modified Duke Criteria
• Definite endocarditis:
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Pathologic evidence of disease OR
2 Major clinical criteria OR
1 Major + 3 minor OR
5 minor
• Possible endocarditis
• 1 Major + 1 minor OR
• 3 minor
IE MAJOR AND MINOR CRITERIA
• Major Criteria
• 1) Positive blood cultures (specific criteria)
• “Typical” organisms: S. aureas, viridans strep, S. Bovis, enterococci,
and HACEK
• 2) Abnormal echocardiogram
• Minor Criteria
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1) Predisposing condition (valve disease or IVDA)
2) Fever
3) Vascular phenomena
4) Immunologic phenomena
5) Positive blood culture that does not meet a major criterion
TREATMENT OF IE
Organisms
Susceptibility
Drug Regimen
Duration
Viridans streptococci,
S. Bovis
PCN-sensitive
PCN G or CTX
4 weeks
Prosth >4 weeks
(PCN G or ctx) + gent
2 weeks
Vancomycin (alt)
4 weeks
PCN-resistant
Increased dose PCN G
4 weeks
S. Aureus or
Coagulase-neg
Methicillin-susc
Nafcillin
Methicillin-resis
Vancomycin
6 weeks
Prosthetic (add
rifampin & gent)
Staph,
uncomplicated rightsided
Methicillin-susc
Nafcillin + gentamicin
or daptomycin
2 weeks
Enterococci
PCN-sens
(PCN G or amp or
vanc) + gent
4-6 weeks
Prosth = 6 weeks
Amp + PCN + Vancresis
Very specialized
Very specialized
Ceftriaxone
4 weeks
Prosth = 6 weeks
HACEK
DIARRHEA DUE TO C. DIFFICILE
• Common causes:
• Clindamycin, cephalosporins, quinolones
• Diagnosis:
• Confirm with stool assay for cytotoxin
• Recommendations:
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Mild-to-moderate: Flagyl 500mg po tid x 10-14 days
Severe disease: Vanco 125mg po qid x 10-14 days
Severe with complications: P.O. Vanco +/- IV Flagyl
1st relapse: Repeat the first regimen
2nd relapse: Vanco 125mg po qid and taper
URINARY TRACT INFECTION
• Microbiology for uncomplicated UTI:
• E. coli (most common 75-95%)
• Other species of Enterobacteriaceae:
• Proteus mirabilis (associated with stones, do add’l workup)
• Klebsiella pneumoniae
• Staphylococcus saprophyticus
• Group B strep (in pregnant women, otherwise contaminant)
• Likely contamination in healthy non-pregnant individuals:
• (lactobacilli, enterococci, coag-neg staph)
URINARY TRACT INFECTION
• Acute uncomplicated cystitis-urethritis
• Bactrim 160/800 (1 DS tab) bid x 3 days OR
• Macrobid 100mg bid x 5 days OR
• Fosfomycine 3g po (single dose)
• Uncomplicated pyelonephritis
• Ciprofloxacin 500mg bid x7 days OR
• Ceftriaxone or quinolone (if requiring IV)
• Complicated pyelonephritis
• Ceftriaxone, cefepime, aztreonam, or quinolone
• Add expanded coverage if ICP or urinary obstruction
CELLULITIS
• Purulent (drainage or exudate w/o drainable abscess) –
d/t community-acquired MRSA
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Clindamycin 300-450mg po tid
Bactrim 1 DS tab bid
Doxycycline 100mg bid
Minocycline 200mg x1, then 100mg bid
Linezolid 600mg bid
• Non-purulent – d/t beta-hemolytic strep and MSSA
PO
Dicloxacillin 500mg q6h
IV
Cefazolin 1-2g q8h
Keflex 400mg q6h +/- Bactrim Oxacillin 2g q4h
Clindamycin 300-450mg q6h
Nafcillin 2g q4h
Clindamycin 600-900mg q8h
ANTIBIOTIC COVERAGE QUICK
GUIDE
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1. Pseudomonas:
• Zosyn
• Aminoglycosides
• Cephalosporins: Ceftazidine, Cefepime
• Fluoroquinolones: Cipro, Levaquin
• Carbipenems: Imipenem, Meropenem
• Aztreonam
• Colistin
2. Anaerobes:
 Flagyl
 Clindamycin
 Zosyn
 Unasyn
 Augmentin
 Carbipenem
 Moxifloxacin
 Tigecycline
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3. MRSA:
 Bactrim
 Clindamycin
 Doxycyclin
 Vancomycin
 Linezolid
 Tigecycline
 Daptomycin – cannot use in lungs!
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4. VRE:
 Linezolid
 Tigecycline
 Daptomycin
TAKE HOME POINTS
• Deescalate antibiotics based on sensitivities
• Antibiotics should be individualized based on
patient circumstances (allergy, tolerability,
compliance), local community resistance
prevalence, availability, cost, and patient and
provider threshold for failure