Transcript The ABC’s of Infections

The ABC’s of
Infections
Eleana M. Zamora, MD
Department of Internal Medicine
Division of Pulmonary/Critical
Care/Sleep
Objectives
• Understand the difference between
nosocomial and community-acquired
• Know where to find antibiogram data
• Have a basic understanding of how to
approach common infections in the
inpatient and outpatient setting
Overview
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Community vs. nosocomial
Upper/Lower respiratory infections
C.difficile-associated diarrhea
Intra-abdominal infections
Skin-soft tissue infections
Bacteremia
Osteomyelitis, septic joints
Gram positives
Gram negatives
Urine Antibiogram
Objectives: Crash Course
• Commonly encountered infections in
inpatient and outpatient settings
– What bugs?
– What drugs?
• Common clinical syndromes
Community vs. Nosocomial
• Why important?
– Atypicals
– MDRO
– MRSA
– Pseudomonas
• Broadened definition of “nosocomial”
– SNF, OPAT, jail, community-living, homeless,
etc.
Common Outpatient Infections
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Upper respiratory
Lower respiratory
Sinusitis
Pharyngitis
UTI
SST
Upper Respiratory Infection
• Def’n:
– Acute infxn which is typically viral
– Sinus, pharngeal, or lower airway symptoms
may be present, but are not prominent
• Abx are rarely indicated
– Although most “colds” have sinus symptoms,
less than 2% have complication of acute
bacterial sinusitis
– Presence of green mucus does not necessarily
indicate bacterial infection
Acute Pharyngitis
• GAS causes 10% of adult pharyngitis
– 90% are NOT GAS!
– DDx: EBV, CMV (less likely), gonococcus,
HSV, HIV, Syphilis
• ABX are rarely indicated for routine
pharyngitis
– Use the Centor diagnostic criteria to decide who
to test
– Treat only positive GAS rapid screens or
patients who have all 4 criteria
Centor Criteria
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History of fever
Tonsillar exudates
No cough
Tender anterior cervical LAD
≥2 of the above = treat
Treatment of GAS Pharyngitis
• Treatment of choice: Penicillin V 500mg BID
or 250mg QID x 10 days
• Alternatives
– Benzathine PCN 1.2 MU IM x 1 dose (for
noncompliant patients)
– 2nd gen cephalosporin: cefuroxime or cefprozil
500 mg qday, etc. etc
– Azithro 500mg x1, then 250mg po day x 4d
– If macrolide failure or pcn-allergy: FQ
– Bactrim does not cover GAS
Acute Sinusitis
• Most cases of sinusitis are viral
• Bacterial rhinosinusitis
– Sx lasting ≥7 d who have maxillary pain or
tenderness in the face or teeth (esp. unilateral)
and purulent nasal secretions
• Severe dz: dramatic symptoms of severe
unilateral maxillary pain, swelling, and
fever.
Sinusitis Guidelines: IDSA 2012
IDSA: Treatment
• First line = B-lactam (amox/clav)
– Preferred over respiratory FQ
– Doxycycline is equivalent to amox/clav
– Not recommended to cover for MRSA
• Not recommended for use:
– Macrolides, Bactrim
• Duration of tx: 5-7 days
– Recommended over 10-14 days
Acute Sinusitis
• Etiology
– Community-acquired from obstruction of ostia,
allergens, post-viral infxn:
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S.pneumo 31%
H.influenzae 21%
M.catarrhalis 10%
S.aureus 4%
– Diabetic, neutropenic, IV iron therapy:
• mucor/rhizopus, aspergillus
Etiology of Acute Sinusitis
– Nosocomial , NGT, or nasal intubation:
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Gram neg (pseudomonas, acinetobacter) 47%
Staph aureus/gram pos 35%
Yeast 18%
Polymicrobial 80%
Chronic Sinusitis
• Pathogenesis is multifactorial
– Smoking
– Nasal polyps
– Periodontitis
• Antibiotics are rarely effective
– Refer to ENT
– STOP SMOKING!
• Atypical pathogens
– Prevotella, anaerobes, fusobacterium,
Pseudomonas, fungi/molds
URI
Non-Specific URI
• Resistant Strep pneumoniae
– outpatient abx
– Treating a viral URI with abx directly increases
the risk of resistant bug transmission
• Upper URI account for over 75% of
outpatient RX each year
For URI Syndromes:
Very strongly consider NO
abx:
• Adult uncomplicated
acute bronchitis
– Not acute exacerbations of
chronic bronchitis)
• Acute sinusitis
• Pharyngitis
• Nonspecific URI
ABX should be used for:
• Documented GAS
pharyngitis
• Severe sinusitis with
fever, ptosis, etc.
• Pneumonia (LRI)
WHATUP!
Lower Respiratory
Lower Respiratory Infections
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Tracheitis – biggest airways
Bronchitis –large airways
Bronchiolitis – smallest airways, wheezing
Pneumonia – air space infection
– Basic concepts are the same for all
Stepwise Approach
• Decide viral, bacterial, atypical, other?
– Not always so easy…sometimes more
than one
– Rule of thumb: cover the top 3
– Risk factors
• Smoking, travel, immunosuppression,
diabetes
Pseudomonas?
• Community-acquired vs. nosocomial +/aspiration
– Hospitalized vs. non-hospitalized
– Remember new broader risk categories for
MDRO
– Pseudomonas and Acinetobacter longer
duration of tx
Powers of Pseudomonas Prediction
Common CAP Etiologies
IDSA CAP Guidelines
2007
Outpatient CAP Tx
To Hospitalize or not?
• Pneumonia severity
index (PSI)
• CURB-65
• Your gut feeling
counts
• CURB-65
• Confusion, Uremia, RR, low BP,
age>65
• Score > 2admit
Severe CAP
• IDSA Guidelines 2007
Inpatient, non-ICU CAP Tx
• UNMH Formulary
1. Ceftriaxone + azithromycin/doxy
2. If β-lactam allergy: moxifloxacin
1. Moxi not for UTI or Pseudomonas
Inpatient CAP, ICU
• UNMH Formulary
1. Ceftriaxone + azithromycin
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Not doxy
2. If β-lactam allergy:
moxifloxacin
Pseudomonal Risk Factors
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UNM: Know the antibiogram!
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Available to you without ID consult: Zosyn (87%S), Cefepime (82%), Cipro (72%), Gent/Tobra
(85%)
ID Consult only: Meropenem (95%), amikacin (89%), doripenem, colistin
Infectious Diarrhea
Clostridium difficile
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SHEA/IDSA Guidelines 2010
Who to test?
What to do?
How to treat?
When to take out of isolation?
The New CDAD
• 4 x’s increase in cases over 13 year period
• Increase in disease severity
• Major risk factors for NAP1 strain
– Age > 65
– Recent use of FQs
Severity assessment score
• ≥2 points
classified as
severe
• 1 point given
for each of the
following:
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Age > 60
Temp >38.3
WBC > 15K
Albumin < 2.5mg/dL
2 points for endoscopic
evidence of CDAD
– (Alternate: AKI)
– (Alternate: sepsis, ICU)
Case Definition
1. Presence of diarrhea (>3 unformed
stools in 24 hours)
2. Stool test positive for Cdiff or its toxins
3. Colonoscopic evidence of Cdifficile
Who to test?
• Anyone with diarrhea?
– Do not test asymptomatic patients
– Only patients with diarrhea, not formed
• Unless toxic megacolon/ileus
• High risk:
– SNF, jail, group home
– Recent (<90d) abx
– Recent (<30d) hospitalization
– Known contact (2-3 days avg)
– Severe, ICU intraabdominal source suspected
What test?
• Previously used test for toxin
• UNMH uses PCR confirmation
– A single test per episode of diarrheal illness is
recommended
– No more than one test every 7 days
– Do not need multiple tests to “rule-out”
– Do not need test of cure
Understanding the test
• Stool tested for Antigen (Ag) and toxin (T)
– Ag (+) T (+)  positive C.diff (red)
– Ag (+) T (-)  reflex to PCR (red)
– Ag (-) T (+)  reflex to PCR (red)
– Ag (-) T (-) negative C.diff
What to do?
• If you think it, patient must be in isolation
– NEVER EVER order the test without putting
patient in isolation at same time
– Never treat empirically without putting in
isolation at same time
• If patient is ill, empiric tx is ok
How to treat?
Consider calling general
surgery for severe disease!
Intra-Abdominal
Complicated Intra-abdominal
Infections
• Examples:
– Perf diverticulum
– Complicated GB infection
– Abscess
– Peritonitis
• Location matters
– Flora of upper small bowel vs. from beyond small
bowel vs. from beyond ileum vs. rectum
It’s All About Location!
• Upper GI, duodenum, biliary system,
proximal small bowel
– Peritonitis common
– Gram pos, gram neg aerobic and facultative
organisms
– Enterococcus is not a real concern
• Distal small bowel
– Less GPC, more GNR (aerobes, facultative)
– Often evolve into abscesses (not peritonitis)
Location, location, location
• Colon
– Facultative (E.coli) and obligate anaerobes
(B.frag), Streptococci (S.bovis)
• Abscesses
– Abscesses, in general, should be drained
– ABX have hard time getting into abscess
• Exception?
– ALWAYS send aspirate for anaerobic/aerobic
culture
So, Why So Complicated?
• Location
– Some drugs are inactive in abscesses
– Some drugs are pH dependent
• Bugs
– Some bugs are resistant
• B.frag vs. clinda/fq/cefotetan/cefoxitin
• Community-Acquired vs. Nosocomial?
– Pseudomonas is less common in abscesses
Who to Treat?
• Bowel trauma that get surgically repaired
within 12 hours, upper GI perf in the
absence of antacids, or acute appendicitis
– Abx used for <24h
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Acute uncomplicated cholecystitis = NO
Ascending cholangitis = YES
Acute pancreatitis = NO
Necrotizing pancreatitis = YES
What to
give?
Note: Empiric coverage of
Candida is NOT
recommended.
If candida is found, strongly
consider if it needs therapy
Questions?
References
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Gonzales et.al. “Principles of Appropriate Antibiotic Use for Treatment of
Nonspecific Upper Respiratory Tract Infections in Adults: Background” Ann Intern
Med. 2001;134:490-494.
Cooper et.al. “Principles of Appropriate Antibiotic Use for Acute Pharyngitis in
Adults: Background” Ann Intern Med. 2001;134:509-517.
Hickner et.al. “Principles of Appropriate Antibiotic Use for Acute Rhinosinusitis in
Adults: Background” Ann Intern Med. 2001;134:498-505.
IDSA Guidelines or Acute Bacerial Rhinosinusitis in Children and Adults 2012
Gonzales R, et.al. “Principles of Appropriate Antibiotic Use for Treatment of Acute
Respiratory Tract Infections in Adults: Background, Specific Aims, and Methods”
Ann Int Med 2001; 134:479-486
Mandell, LA, et.al. “Infectious Diseases Society of America/American Thoracic
Society Consensus Guidelines on the Management of Community-Acquired
Pneumonia in Adults” CID 2007;44:S27-72
Joint statement of ATS/IDSA 2004 “Guidelines for the Management of Adults with
Hospital-acquired, Ventilator-associated, and Healthcare-associated Pneumonia”
Am J Respir Crit Care Med 171:388-416
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Cohen SH, et.al. “Clinical Practice Guidelines for Clostridium difficile Infection in
Adults: 2010 Update by the Society for Heathcare Epidemiology of America (SHEA)
and the Infectious Diseases Society of America (IDSA)” ICHE 2010;31(5): 000-000
Solomkin JS, et.al. “Diagnosis and Management of Complicated Intra-abdominal
Infection in Adults and Children: Guidelines by the Surgical Infection Society and
the Infectious Diseases Society of America.” CID 2010;50:133-64
Stevens DL, et.al. “Practice Guidelines for the Diagnosis and Management of Skin
and Soft-Tissue Infections” CID 2005;41:1373-1406
Lipsky, BA, et.al. “Diagnosis and Treatment of Diabetic Foot Infections” CID
2004;39:885-910
Nicolle, LE, et.al. “Infectious Disease Society of America Guidelines for the
Diagnosis and Treatment of Asymptomatic Bacteriuria in Adults” CID 2005;40-64354
Hooton TM, et.al. “Diagnosis, prevention, and Treatment of Catheter-Associated
Urinary Tract Infection in Adults: 2009 International Clinical Practice Guidelines
from the Infectious Disease Society of America.” CID 2010;50:625-663.