Community-Acquired
Pneumonia
Shireesha Dhanireddy, MD
Division of Allergy & Infectious Diseases
University of Washington
12 September 2014
Objectives

Diagnosis and management of CAP

Differentiate between healthcare-associated
pneumonia (HCAP) and CAP

Identify risk factors for resistant organisms
and less common causes of pneumonia
CAP - Epidemiology

Very common




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5 million cases/year in North America
At least 1 million hospitalizations/year
9th leading cause of infectious death in US
30 day morality for hospitalized patients is up
to 23%
$17 billion/year in healthcare costs in US
www.cdc.gov/flu
Which of these patients have
community-acquired pneumonia
(CAP)?
✔
34
yo hospital employee, previously healthy,
admitted for acute pneumonia.
✔56
yo man admitted with CHF, noted to have
pneumonia the day after admission.

76 yo bedridden man transferred from a nursing
home for acute confusion, noted to have a new
infiltrate on CXR.
Alphabet Soup of Terms

CAP: Community-acquired pneumonia


HCAP: Healthcare-associated pneumonia


Long-term or extended care facility, hemodialysis,
outpatient chemo, wound care, etc.
HAP: Hospital-acquired pneumonia


Outside of hospital or extended-care facility
≥ 48 h from admission
VAP: Ventilator-associated pneumonia

≥ 48 h from endotracheal intubation
Pneumonia - Definitions
Kollef MH et al. CID 2008:46 (suppl 4)
Case 1
70 yo man presents to ED with acute onset of cough
productive of yellow sputum, R-sided pleuritic CP and
dizziness.
Hx diabetes
and
HTN.
Meds include:
HCTZ,
Which
of following
is the
most
appropriate
management?
lisinopril, glyburide and metformin.
1. Admit to general medical floor.
T 35°
C, BP 110/70
HR 120 RR 36
2.PEx:
Admit
to intensive
care unit.
3.GEN:
Observe
in the
ED forrespiratory
12 hours.distress. PULM:
Appears
in acute
4.Dullness
Treat astooutpatient.
percussion, increased fremitus, crackles at R
base. NEURO: Oriented only to self.
LABS: WBC 23 (40% bands), Hct 42%, Plts 150. BUN 46,
Cr 1.4.
ABG: 7.48 /30 /50 on RA. CXR shows RLL infiltrate.
Clinical Presentation
Acute cough (>90%)
Fevers/chills (80%)
Sputum production (66%)
Dyspnea (66%)
Pleuritic chest pain (50%)
Tachypnea (RR > 24)
Egophony
Bronchial breath sounds
Percussion dullness
Diminished breath sounds
Clinical Presentation
Acute cough (>90%)
Fevers/chills (80%)
Sputum production (66%)
Dyspnea (66%)
Pleuritic chest pain
(50%)
Lung
physical
exam
Sensitivity 47-69% ; Specificity 58-75%
Tachypnea (RR > 24)
Egophony
Bronchial breath sounds
Percussion dullness
Diminished breath sounds
CXR
To Admit or Not?
Pneumonia Severity & Deciding Site of
Care

Objective criteria to risk stratify & assist in decision re
outpatient vs inpatient management

Pneumonia Severity Index (PSI)

CURB-65

Caveats
 Other reasons to admit apart from risk of death
 Not validated for ward vs ICU
 Not validated in some populations (i.e. HIV+)
70
20
15
20
10
Total 135
Criteria for Severe CAP
(Admit to ICU)
Minor criteria
Respiratory rate ≥30 breaths/min
PaO2/FiO2 ratio ≥ 250
Multilobar infiltrates
Confusion/disorientation
Uremia (BUN ≥20 mg/dL)
Leukopenia (WBC <4000 cells/mm3)
Thrombocytopenia (platelets <100,000 cells/mm3)
Hypothermia (core T <36C)
Hypotension requiring aggressive fluid resuscitation
Major criteria
Invasive mechanical ventilation
Septic shock with the need for vasopressors
2007 IDSA/ATS Guidelines for CAP in Adults.
Microbiology
TYPICAL
– Streptococcus pneumoniae
– Haemophilus influenzae
– Moraxella catarrhalis
– Klebsiella pneumoniae
ATYPICAL
– Mycoplasma pneumoniae
– Chlamydophila pneumoniae
– Legionella pneumophila
Microbiology of CAP among
hospitalized patients
Outpatient
Streptococcus pneumoniae
Mycoplasma pneumoniae
Haemophilus influenzae
Chlamydophila pneumoniae
Respiratory viruses
Inpatient (Ward)
S. pneumoniae
M. pneumoniae
H. influenzae
C. Pneumoniae
Legionella species
Respiratory viruses
Aspiration
Inpatient (ICU)
S. pneumoniae
Legionella spp.
Staphylococcus aureus
Gram-negative bacilli
Age-specific
Rates of
Hospital
Admission by
Pathogen
Marsten. Community-based pneumonia incidence study group.
Arch Intern Med 1997;157:1709-18
Comorbidities & Associated
Pathogens
Alcoholism





Strep pneumoniae
Oral anaerobes
Klebsiella pneumoniae
Acinetobacter spp
M. tuberculosis
COPD and/or
Tobacco






Haemophilus influenzae
Pseudomonas aeruginosa
Legionella spp
S. pneumoniae
Moraxella catarrhalis
Chlamydophila pneumoniae
Aspiration
Lung Abscess
Structural lung
disease (e.g.
bronchiectasis)
Advanced HIV




Gram-negative enteric pathogens
Oral anaerobes
CA-MRSA
Oral anaerobes, microaerophilic
streptococci, Actinomyces, Nocardia spp
 Endemic fungi
 M. tuberculosis, atypical mycobacteria
 P. aeruginosa
 Burkholderia cepacia
 S. aureus






Pneumocystis jirovecii
Cryptococcus
Histoplasma
Tuberculosis
Aspergillus
P. aeruginosa
MRSA
Modern-day CAP pathogen



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

51 Staphylococcus aureus CAP cases in 19 states
reported 2006-2007
79% MRSA
Median age 16 yrs (range <1 to 81)
47% antecedent viral illness
11 of 33 (33%) tested had lab-confirmed influenza
51% died a median of 4 days from symptom onset
Lesson: Must consider MRSA, MSSA coverage in
severe CAP, esp during flu season!
Kallen, Ann Emerg Med. 2009 Mar;53(3):358-65.
MRSA CAP
Clinical Features


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Cavitary infiltrate or necrosis
Rapidly increasing pleural effusion
Gross hemoptysis (not just blood-streaked)
Concurrent influenza
Neutropenia
Erythematous rash
Skin pustules
Young, previously healthy patient
Severe pneumonia during summer months
Wunderink, N Engl J Med. 2014;370:543-51.
Is sputum culture helpful?

Sputum Gram stain
and culture



Low sensitivity (25-40%)
Considered optional for
outpatients
Blood culture


Positive < 10%
May help guide
antibiotic therapy
textbookofbacteriology.net
Diagnosis: Cultures

Pre-abx Blood Cultures




Pre-abx expectorated sputum Gs & Cx





Yield 5-15%
Stronger indication for severe CAP
Host factors: cirrhosis, asplenia, complement
deficiencies, leukopenia
Yield can be variable
Depends on multiple factors: specimen collection,
transport, speed of processing, use of cytologic criteria
Adequate sample w/ predominant morphotype seen in
only 14% of 1669 hospitalized CAP pts (Garcia-Vasquez,
Arch Intern Med 2004)
Pre-abx endotracheal aspirate Gs & Cx
Pleural effusions >5 cm on lateral upright CXR
Diagnosis: Other testing

Urinary antigen tests

S. pneumoniae

L. pneumophila serogroup 1

60-80% sensitive, >90%
specific in adults

Pros: rapid (15 min), simple,
more sensitive than Cx, can
detect Pneumococcus after
abx started

Cons: no susceptibility data,
not helpful in patients with
recent CAP (prior 3 months)
Diagnosis: Other testing

Acute-phase serologies



C. pneumoniae, Mycoplasma, Legionella spp
Not practical given slow turnaround & single acute-phase
result unreliable
Influenza testing

Hospitalized patients: Severe respiratory illness (T> 37.8°C
with SOB, hypoxia, or radiographic evidence of pneumonia)
without other explanation and suggestive of infectious etiology
should get screened during season

NP swab or nasal wash/aspirate
Rapid flu test (15 min) - Distinguishes A vs B
 Sensitivity 50-70%; specificity >90%
Respiratory virus DFA & culture - reflex subtyping for A
Respiratory viral PCR panel - reflex subtyping for A
Epidemic Influenza PCR panel – screens for A & B with
reflex subtyping for A


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
Case
29 yo previously healthy but morbidly obese woman admitted
in March with 5 days of progressive SOB, intubated in field
after being found home unresponsive, hypoxic with Sat 80%.
Initial BP 100/80, HR 120. PaO2 60 on 80% FiO2.
CXR reveals diffuse patchy infiltrates with some lower lobar
consolidation R>L.
Sputum could not be obtained but endotracheal aspirate
shows 3+ polys and 3+GPC in clusters. Which of the following
abx would you start empirically?
1.
2.
3.
4.
5.
Ceftriaxone + azithromycin
Zanamavir + vancomycin + azithromycin
Oseltamavir + vancomycin + azithromycin
Oseltamavir + vancomycin + piperacillin-tazobactam
Oseltamavir + daptomycin + azithromycin
Outpatient Empiric CAP Abx

Healthy; no abx x past 3 months



Comorbidities; abx x past 3 mon



Macrolide: azithromycin
2nd choice: doxycycline
Respiratory fluoroquinolone: Moxifloxacin, levofloxacin
750 mg, gemifloxacin
Beta-lactam (preferred: amoxicillin 1 g3 or amox/clav 2
g2; alternative: ceftriaxone, cefuroxime 500 mg2), +
macrolide
Regions with >25% high-level macrolide-resistant S.
pneumo (MIC ≥16), consider alternative agents
2007 IDSA/ATS Guidelines for CAP in Adults.
Inpatient Empiric CAP Abx1

Inpatients in ward



Inpatients in ICU



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
ß-lactam + macrolide
Respiratory fluoroquinolone for PCN-allergic pts
Pseudomonas (if concerns exists)


Respiratory fluoroquinolone
ß-lactam (cefotaxime/ceftriaxone or ampicillin/sulbactam) +
macrolide
Anti-pneumococcal & anti-pseudomonal ß-lactam +
azithromycin + cipro/levofloxacin (750 mg)
Can substitute quinolone with aminoglycoside
PCN-allergic: can substitute aztreonam
CA-MRSA: Add vanco or linezolid* (or ceftaroline2)
CA-MSSA: Nafcillin or cefazolin or ceftriaxone
1 2007
IDSA/ATS Guidelines for CAP in Adults.
2 File, et. al. CID 2010. 51(12): 1395-1405.
Risk Factors for Multidrug
Resistance (MDR)
Antibiotics in the past 90 days
High frequency of antibiotic resistance in community
Immunosuppressive disease or medications
HCAP Risk Factors:
• Hospitalization for at least 2 days in the past 90 days
• Residence in a SNF
• Home infusion therapy
• Dialysis within 30 days
• Family member with MDR infection
Kollef MH et al. CID 2008:46 (suppl 4)
Kollef MH et al. CID 2008:46 (suppl 4)
Influenza pneumonia
Treatment


First-line Tx is neuroaminidase inhibitors for both
influenza A and B:

Oseltamavir 75-150* mg PO BID x 5+ days

Zanamavir 10 mg INH BID x 5+ days
NOTE: influenza A resistant to adamantanes
(amantadine, rimantadine)
* There is limited data in support of double dosing. But we
do it anyway.
Antiviral Therapy for Influenza
Should be started ASAP in:

Anyone hospitalized with suspected or confirmed
influenza

Anyone with severe, complicated or progressive
respiratory illness

Anyone at higher risk of complications from influenza
CDC Guidelines for Influenza 2012-2013
Individuals at Higher Risk for
Influenza Complications


Extremes of age: children <2, adults ≥65 years
Comorbid conditions:

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
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


Chronic pulmonary
Cardiovascular (except HTN alone)
Renal, hepatic, hematologic, metabolic (DM)
Neurologic, neuromuscular (cerebral palsy, epilepsy, CVA, SCI)
Immunosuppression (caused by meds, HIV infection)
Pregnant or post-partum (<2 wks) women
Persons <19 years on long-term aspirin
American Indians & Alaskan Natives
Morbidly obese (BMI ≥40)
Residents in NH or chronic-care facilities
CDC Guidelines for Influenza 2012-2013
Influenza pneumonia
What about the 48-hr rule?

Antiviral treatment within 48 hrs



Reduce likelihood of lower tract complications &
antibacterial use in outpatients
Hospitalized patients likely benefit even if started up to 35 days from illness onset 1,2,3
Additional exceptions to <48 h rule:


Immunocompromised patients
Severe, complicated or progressive illness
1 Siston,
et. al. JAMA 2009.
Clin Infect Dis 2011.
3 Louie, Clin Infect Dis 2012.
2 Yu,
Follow-up Response
Expected improvement?



Clinical improvement w/ effective abx: 48-72 hrs
Fever can last 2-5 days with Pneumococcus, longer
with other etiologies, esp Staph aureus
CXR clearing



If healthy & <50 yo, 60% have clear CXR x 4 wks
If older, COPD, bacteremic, alcoholic, etc. only 25% with
clear CXR x 4 wks
Switch from IV to PO


Hemodynamically stable, improving clinically
Able to ingest meds with working GI tract
Question…
What is far & away the most common reason
for non-response to antibiotics in CAP?
1.
2.
3.
4.
5.
Cavitation
Pleural effusion
Multilobar involvement
Discordant antibiotic/etiology
Host factors
• May. Kennewick, WA.
• A 58 y/o man with advanced liver disease,
construction worker in outdoor excavation
• C/O acute fever, cough, pleuritic chest pain,
WBC 23,000.
• CXR and chest CT show RML nodule and
effusion. No response to Unasyn + Levo.
• Concern for pneumococcal pneumonia.
Thoracentesis and BAL are performed….
NW Infections: Coccidioides
Coccidioides immitis
- Endemic to the desert southwest
- Dissemination more common in non-Caucasians,
pregnant, immunocompromised
- Acute & chronic pulmonary syndromes (“valley
fever”—fever, cough, arthralgias, Erythema
nodosum)
- Diagnosis based on serology, culture, or
histopathology
Exposures & Associated Pathogens
Hotel or cruise ship, built water
sources
Travel or residence in SW US
Travel or residence in SE or E
Asia
 Legionella spp
 Coccidioides spp
 Hantavirus pulmonary
syndrome (Sin Nombre virus)
 Burkolderia pseudomallei
 Avian influenza A (H7N9)
Travel or residence in Arabian
Peninsula
 MERS-CoV
Influenza active in community




Cough >2 wks with whoop or
posttussive vomitting
 Bordetella pertussis
Influenza
S. pneumoniae
Staph aureus (MSSA, MRSA)
H. influenzae
Zoonotic Exposures & Associated
Pathogens
Bat or bird
droppings
 Histoplasma capsulatum
Birds
 Chlamydophila psittaci
 Avian influenza (H7N9)
Rabbits
 Francisella tularensis
Farm animals or
parturient cats
 Coxiella burnetti (Q fever)
Take Home Points

Ask patients about co-morbidities and
travel/other potential exposures when they
present with a respiratory illness

Evaluate patients for MDR risk factors when
managing patients in the community with
respiratory illness