CDC Etiology of Pneumonia in the Community (EPIC) Study of Community-Acquired Pneumonia (CAP) Requiring Hospitalization in the US (NEJM, 2015) [MEDLINE]
Incidence
Annual Community-Acquired Pneumonia Incidence was 24.8 Cases Per 10k Adults
Highest Community-Acquired Pneumonia Rates were Observed Among the 65-79 y/o Age Group (63.0 Cases Per 10k Adults) and Among the ≥80 y/o Age Group (164.3 Cases Per 10k Adults)
Community-Acquired Pneumonia Incidence Increased with Age for All of the Pathogens
Median Age of Community-Acquired Pneumonia Patients was 57 y/o
Pathogen Identification and Distribution
A Community-Acquired Pneumonia Pathogen was Detected in Only 38% of Cases
One or More Viruses: 23% of cases
Bacteria: 11% of cases
Bacterial and Viral Pathogens: 3% of cases
Fungal or Mycobacterial Pathogen: 1% of cases
Approximately 5% of Cases Had Co-Detected Pathogens (i.e More Than One Pathogen Detected)
Incidence of Community-Acquired Pneumonia Pathogens (In Descending Order of Incidence)
Approximately 21% of Community-Acquired Pneumonia Cases Required ICU Care
Overall Mortality Rate was 2%
Predisposing Factors/Epidemiologic Factors Associated with Various Infectious Etiologies of Community-Acquired Pneumonia (Clin Infect Dis, 2007) [MEDLINE]
Advanced Age
General Risk
Systematic Review of Risk Factors for Community-Acquired Pneumonia in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
Factors Associated with an Increased Risk of Community-Acquired Pneumonia
In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Chronic Kidney Disease was Associated in 31.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Chronic Lung Disease was Associated in 34.7% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
Studies Suggest that Cirrhosis is Associated with an Increased Risk for Staphylococcus Aureus Pneumonia in the Hospital Setting (Pulm Med, 2016) [MEDLINE] (Chin Med J (Engl), 2019) [MEDLINE]
In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Cardiovascular Disease was Associated in 31.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
Systematic Review of Risk Factors for CAP in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
Factors Associated with an Increased Risk of Community-Acquired Pneumonia
English Retrospective Cohort Study of Primary Care Patients with/without Type 1/II Diabetes (Diabetes Care, 2018) [MEDLINE]: 102,493 primary care patients (age 40-89 y/o)
Risk of Pneumonia (Type I DM): Incidence Rate Ratio 2.98 (95% CI: 2.40–3.69)
Risk of Pneumonia (Type II DM): Incidence Rate Ratio 1.58 (95% CI: 1.53–1.64)
South Korean National Chort Study (Diabetes Metab J, 2019) [MEDLINE]: n = 66,426 diabetics and 132,852 age/sex/region-matched non-diabetic controls
Diabetics Had an Increased Risk of Respiratory Infection (Adjusted Incidence Ratio 1.76; 95% CI: 1.72–1.81)
Diabetics Had an Increased Risk of Pneumonia (Adjusted Incidence Ratio Ratio 1.57; 95% CI, 1.52-1.62)
Spanish Study of Community-Acquired Pneumonia in Primary Care (BMC Infect Dis, 2019) [MEDLINE]: n = 51,185
Approximately 16% of Community-Acquired Pneumonia Patients in the Primary Care Setting Had Diabetes as Comorbidity
Study of Risk Scoring System to Identify Patients with MRSA Admitted with CAP (BMC Infect Dis, 2013) [MEDLINE]: n = 5975
Risk Factors Included Recent Hospitalization or ICU Admission (2 pts), Female Sex with Diabetes (1 pt), Age <30 or >79 (1 pt), Prior Antibiotic Exposure (1 pt), Dementia (1 pt), Cerebrovascular Disease (1 pt), Recent Exposure to a Nursing Home/Long-Term Acute Care Facility/Skilled Nursing Facility (1 pt)
Prevalence of MRSA Increased with Increasing Score: Low Risk (0 to 1 pts), Medium Risk (2-5 pts) and High Risk (≥6 pts)
In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Diabetes Mellitus was Associated in 29.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
Studies Suggest that Diabetes Mellitus is Associated with an Increased Risk for Staphylococcus Aureus Pneumonia in the Hospital Setting (Pulm Med, 2016) [MEDLINE] (Chin Med J-Engl, 2019) [MEDLINE]
In VA Retrospective Cohort Studies (n = 34,759), Patients with Diabetes Taking Metformin and Who are Hospitalized with Pneumonia were Demonstrated to Be at Decreased Risk of Mortality (Clin Infect Dis, 2022) [MEDLINE] (see Metformin)
Unadjusted 30-Day Mortality was 9.6% for Patients Who Had Received Metformin vs 13.9% in Patients Who Had Not Received Metformin (P < 0.003)
Unadjusted 90-Day Mortality was 15.8% for Patients Who Had Received Metformin vs 23.0% for Patients Who Had Not Received Metformin (P < 0.0001)
After Propensity Matching, Both 30-day (Relative Risk 0.86; 95% CI 0.78-0.95) and 90-Day (Relative Risk 0.85; 95% CI: 0.79-0.92) Mortality was Significantly Lower for Metformin Users
Systematic Review of Risk Factors for CAP in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
Factors Associated with an Increased Risk of Community-Acquired Pneumonia
Systematic Review and Meta-Analysis of the Effect of Tobacco Smoking on the Risk of Developing Community-Acquired Pneumonia (PLoS One, 2019) [MEDLINE]: n = 27 studies
Current Smokers (Pooled OR 2.17, 95% CI: 1.70-2.76, n = 13 Studies; Pooled HR 1.52, 95% CI: 1.13-2.04, n = 7 Studies) and Ex-Smokers (Pooled OR 1.49, 95% CI: 1.26-1.75, n = 8 Studies; Pooled HR 1.18, 95% CI: 0.91-1.52, n = 6 Studies) Had an Increased Risk of Developing CAP, as Compared to Never Smokers
Dose-Response Analyses of Data from 5 Studies Indicated a Significant Trend, Such that Current Smokers Who Smoked a Higher Amount of Tobacco Had a Higher CAP Risk
Although the Association Between Passive Smoking and Risk of CAP in Adults of All Ages was Not Statistically Significant (Pooled OR 1.13, 95% CI: 0.94-1.36, n = 5 Studies), Passive Smoking in Adults ≥65 y/o was Associated with a 64% Increased CAP Risk (Pooled OR 1.64; 95% CI: 1.17-2.30, n = 2 Studies)
CDC Etiology of Pneumonia in the Community (EPIC) Study of Community-Acquired Pneumonia (CAP) Requiring Hospitalization in the US (NEJM, 2015) [MEDLINE]
General Comments
A Community-Acquired Pneumonia Pathogen was Detected in Only 38% of Cases
Approximately 5% of Cases Had Co-Detected Pathogens (i.e More Than One Pathogen Detected)
Most Common Community-Acquired Pneumonia Pathogens
Risk Factors for Staphylococcus Aureus Community-Acquired Pneumonia
Influenza Active in Community
Specific Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) Community-Acquired Pneumonia
Hospitalization with Intravenous Antibiotic Exposure within the Last 90 Days (Am J Respir Crit Care Med, 2019) [MEDLINE]
Prior Identification of Methicillin-Resistant Staphylococcus Aureus (MRSA) in the Respiratory Tract within the Prior Year (Am J Respir Crit Care Med, 2019) [MEDLINE]
General Comments Regarding Diagnostic Testing for Patients with Community-Acquired Pneumonia (CAP)
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Patients with Community-Acquired Pneumonia Should Undergo Diagnostic Testing to Detect Specific Suspected Pathogens that Would Significantly Alter the Choice of Empiric Antibiotic Therapy (Strong Recommendation, Level II Evidence)
Routine Diagnostic Testing to Identify an Etiologic Organism in Outpatients with Community-Acquired Pneumonia is Optional (Moderate Recommendation, Level III Evidence)
Dutch Cross-Sectional Study of Symptoms, Signs, Erythrocyte Sedimentation Rate, C-Reactive Protein in the Diagnosis of Pneumonia by Outpatient General Practitioners (Br J Gen Pract, 2003) [MEDLINE]: n= 246 presenting with lower respiratory tract infection
Dry Cough, Diarrhea, and T >38 Degrees C were Statistically Significant Predictors of Pneumonia
Pulmonary Auscultation and Clinical Diagnosis of Pneumonia by the General Practitioner were Not Statistically Significant Predictors of Pneumonia
Erythrocyte Sedimentation Rate and C-Reactive Protein Had Higher Diagnostic Odds Ratios than Any of the Symptoms
Adding C-Reactive Protein to the Final Symptoms and Signs Model Significantly Increase the Probability of Correct Diagnosis
Applying a Prediction Rule for Low-Risk Patients (Including a C-Reactive Protein <20 mg/dL), 80 of the 193 Antibiotic Prescriptions Could Have Been Prevented with a Maximum Risk of 2.5% of Missing a Pneumonia Case
Dutch Cross-Sectional Study of Symptoms, Signs, Erythrocyte Sedimentation Rate, C-Reactive Protein in the Diagnosis of Pneumonia by Outpatient General Practitioners (Br J Gen Pract, 2003) [MEDLINE]: n= 246 presenting with lower respiratory tract infection
Dry Cough, Diarrhea, and T >38 Degrees C were Statistically Significant Predictors of Pneumonia
Pulmonary Auscultation and Clinical Diagnosis of Pneumonia by the General Practitioner were Not Statistically Significant Predictors of Pneumonia
Erythrocyte Sedimentation Rate and C-Reactive Protein Had Higher Diagnostic Odds Ratios than Any of the Symptoms
Adding C-Reactive Protein to the Final Symptoms and Signs Model Significantly Increase the Probability of Correct Diagnosis
Applying a Prediction Rule for Low-Risk Patients (Including a C-Reactive Protein <20 mg/dL), 80 of the 193 Antibiotic Prescriptions Could Have Been Prevented with a Maximum Risk og 2.5% of Missing a Pneumonia Case
Serum Procalcitonin is the Peptide Precursor of Calcitonin Which is Released by Parenchymal Cells in Response to Bacterial Toxins
Serum Procalcitonin is Elevated in Bacterial Infections
Serum Procalcitonin is Downregulated in Viral Infections
Clinical Efficacy
Cochrane Database Systematic Review and Meta-Analysis of Using Serum Procalcitonin to Start or Stop Antibiotics in Acute Respiratory Tract Infection (Cochrane Database Syst Rev, 2017) [MEDLINE]
Use of Serum Procalcitonin to Guide Initiation and Duration of Antibiotics Results in Lower Risks of Mortality, Lower Antibiotic Consumption, and Lower Risk of Antibiotic-Associated Adverse Effects
Results were Similar for Different Clinical Settings and Types of Acute Respiratory Tract Infections
Future Research is Required to Confirm the Results in Immunocompromised Patients and Patients with Non-Respiratory Infections
Prospective Multicenter Study of the Ability of Serum Procalcitonin to Differentiate Viral vs Bacterial Pneumonia at Hospital Admission (Clin Infect Dis, 2017) [MEDLINE]: n = 1,735
Median Procalcitonin Concentration was Lower with Viral Pathogens (0.09 ng/mL; Interquartile Range <0.05-0.54 ng/mL) than Atypical Bacteria (0.20 ng/mL; Interquartile Range <0.05-0.87 ng/mL; P = 0.05), and Typical Bacteria (2.5 ng/mL; IQR, 0.29-12.2 ng/mL; P < 0.01)
Procalcitonin Discriminated Bacterial Pathogens, Including Typical and Atypical Bacteria, from Viral Pathogens with an Area Under the Receiver Operating Characteristic Curve of 0.73 (95% CI: 0.69-0.77)
A Procalcitonin Threshold of 0.1 ng/mL Resulted in 80.9% (95% CI, 75.3%-85.7%) Sensitivity and 51.6% (95% CI, 46.6%-56.5%) Specificity for Identification of Any Bacterial Pathogen
Procalcitonin Discriminated Between Typical Bacteria and the Combined Group of Viruses and Atypical Bacteria with an Area under the Receiver Operating Characteristic Curve of 0.79 (95% CI: 0.75-0.82)
In Conclusion, No Procalcitonin Threshold Perfectly Discriminated Between Viral and Bacterial Pathogens, But Higher Procalcitonin Strongly Correlated with Increased Probability of Bacterial Pathogens (Particularly Typical Bacteria)
Meta-Analysis of Serum Procalcitonin in Acute Respiratory Tract Infection (Lancet Infect Dis, 2018) [MEDLINE] (Lancet Infect Dis, 2018) [MEDLINE]
Reported Sensitivity of Serum Procalcitonin to Detect Bacterial Infection Ranges from 38-91%, Underscoring that This Test Alone Cannot Be Used to Justify Withholding Antibiotics from Patients with Community-Acquired Pneumonia
ProACT Trial of Procalcitonin Use for Suspected Lower Respiratory Tract Infection (NEJM, 2018) [MEDLINE]: n = 1656
The Provision of Procalcitonin Assay Results, Along with Instructions on Their Interpretation, to Emergency Department and Hospital-Based Clinicians Did Not Result in Less Use of Antibiotics Than Did Usual Care Among Patients with Suspected Lower Respiratory Tract Infection
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
Empiric Antibiotic Therapy Should Be Initiated in Adults with Clinically Suspected and Radiographically Confirmed Community-Acquired Pneumonia, Regardless of Initial Serum Procalcitonin Level (Strong Recommendation, Moderate Quality of Evidence)
Army Medical Center Emergency Department Study of the Diehr Rule for the Prediction of Pneumonia in Patients Presenting with Acute Cough (J Chronic Dis, 1984) [MEDLINE]: n = 1,819
Pneumonia was Radiographically Diagnosed in 2.6% of the Patients
Clinical Decision Rule (Validated in 483 Patients)
Rhinorrhea: -2 point
Sore Throat: -1 point
Night Sweats/Myalgias/All-Day Sputum Production: 1 point
Respiratory Rate >25 breaths/min: 2 points
T >100 °F (37.8 °C)
Interpretation of Score
Score of -2 to -3 Points: likelihood of pneumonia was<1%
Score of 3-6 Points: likelihood of pneumonia was 27%
Emergency Department Study of Gennis Rule for the Diagnosis of Pneumonia (J Emerg Med, 1989) [MEDLINE]: n= 308
38% of the Patients Had Radiographic Pneumonia
Symptoms
No Single Symptom or Sign was Reliably Predictive of Pneumonia
Cough was the Most Common Symptom (Present in 86% of Cases, But was Equally Common in Patients without Pneumonia)
Fever was Absent in 31% of Patients with Pneumonia
Abnormal Lung Exam (Rales, Rhonchi, Decreased Breath Sounds, Wheezes, Altered Fremitus, Egophony, Dullness to Percussion) were Found in <50% of the Patients with Pneumonia and 22% of Patients with a Completely Normal Lung Exam Had Pneumonia
Rule Criteria for Obtaining a Chest X-Ray, Based on Presence of At Least One of the Following (97% Sensitivity)
Temperature >100 °F (37.8 °C)
Heart Rate >100 beats/min
Respiratory Rate >20 breaths/min
Emergency Department Prospective Observational Study of Singal Rule for the Diagnosis of Pneumonia (Ann Emerg Med, 1989) [MEDLINE]: n = 255 adults
15.6% of Adult Patients Had Radiographic Pneumonia
Univariate Predictors of Pneumonia were Fever, Cough, Crackles
In Absence of Fever, Cough, and Crackles, Incidence of Pneumonia was Only 4.3%
Emergency Department Study of the Heckerling Rule for the Diagnosis of Pneumonia (Ann Intern Med, 1990) [MEDLINE]: n= 1,436 (3 different emergency departments)
Rule was Developed in 1,134 Patients and Validated in 302 Patients
Rule Criteria for Obtaining a Chest X-Ray (from Stepwise Logistic Regression Model; p <0.001)
Temperature >100 °F (37.8 °C): 1 point
Heart Rate >100 beats/min: 1 point
Crackles: 1 point
Decreased Breath Sounds (Locally): 1 point
Absence of Asthma: 1 point
Interpretation of Score (Pre-Test Probability was 5% in Primary Care and 15% in Emergency Department)
Score 0
Post-Test Probability of Pneumonia (Primary Care): 1%
Post-Test Probability of Pneumonia (Emergency Department): 2%
Likelihood Ratio: 0.12
Score 1
Post-Test Probability of Pneumonia (Primary Care): 1%
Post-Test Probability of Pneumonia (Emergency Department): 3%
Likelihood Ratio: 0.2
Score 2
Post-Test Probability of Pneumonia (Primary Care): 4%
Post-Test Probability of Pneumonia (Emergency Department): 11%
Likelihood Ratio: 0.7
Score 3
Post-Test Probability of Pneumonia (Primary Care): 8%
Post-Test Probability of Pneumonia (Emergency Department): 22%
Likelihood Ratio: 1.6
Score 4
Post-Test Probability of Pneumonia (Primary Care): 27%
Post-Test Probability of Pneumonia (Emergency Department): 56%
Likelihood Ratio: 7.2
Score 5
Post-Test Probability of Pneumonia (Primary Care): 47%
Post-Test Probability of Pneumonia (Emergency Department): 75%
Likelihood Ratio: 17
Rule Had a Receiver Operating Characteristic (ROC) Area 0.82
In the Validation Sets, the Rule Discriminated Pneumonia and Non-Pneumonia with ROC Areas of 0.82 and 0.76 (After Adjusting for Differences in Disease Prevalence)
Comparative Prospective Study of Diehr/Gennis/Heckerling/Singal Rules with Physician Judgement for the Diagnosis of Pneumonia in Emergency Department and Outpatient Settings (Ann Emerg Med, 1991) [MEDLINE]: n = 290
All Patients Had an Acute Cough and Fever, Hemoptysis, or Sputum Production
7% of Patients Had Radiographic Pneumonia (6% in Outpatient Setting, 10% in Emergency Department)
Recommendations (American Academy of Family Physicians/AAFP Point-of-Care Guidelines) (Am Fam Physician, 2007) [MEDLINE]
Simple Rule for Determining the Need for Chest Radiography in Patients with Acute Respiratory Illness
Chest Radiography Should Be Performed if Either of the Following are Present
Presence of One of the Following
T >100 °F (37.8 °C)
Heart Rate >100 Beats/min
Respiratory Rate >20 Breaths/min
Presence of Two of the Following
Absence of Asthma
Crackles (Rales)
Decreased Breath Sounds
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Demonstrable Infiltrate by Chest X-Ray or Chest CT (with/without Supporting Microbiologic Data) is Required for the Diagnosis of Pneumonia (Moderate Recommendation, Level III Evidence)
Chest CT has Higher Sensitivity for the Detection of Infiltrates than Chest X-Ray
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Demonstrable Infiltrate by Chest X-Ray or Chest CT (with/without Supporting Microbiologic Data) is Required for the Diagnosis of Pneumonia (Moderate Recommendation, Level III Evidence)
In the Outpatient Setting, Yield of Blood Cultures in Patients with Community-Acquired Pneumonia is 2% (Am J Respir Crit Care Med, 2019) [MEDLINE]
In the Inpatient Setting, Yield of Blood Cultures in Patients with Community-Acquired Pneumonia is 9% (Am J Respir Crit Care Med, 2019) [MEDLINE]
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
In the Outpatient Setting, Blood Cultures are Not Recommended in Adults with Community-Acquired Pneumonia (Strong Recommendation, Very Low Quality of Evidence)
In the Inpatient Setting, Blood Cultures are Not Routinely Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Very Low Quality of Evidence)
Indications for Blood Cultures (Any of the Following)
Empiric Treatment for Either Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Strong Recommendation, Very Low Quality of Evidence)
Prior Infection with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Especially Prior Respiratory Tract Infection) (Conditional Recommendation, Very Low Quality of Evidence)
These are the Strongest Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
Prior Hospitalization or Receipt of Parenteral Antibiotics within the Last 90 Days (Conditional Recommendation, Very Low Quality of Evidence)
These Factors Increase the Risk of Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Strong Recommendation, Very Low Quality of Evidence)
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
Endotracheal Tube Aspirate: when patient is intubated
Expectorated Sputum Culture: when patient is not intubated
Procedures
Bacterial Gram Stain and Culture
Fungal Stain and Culture: recommended for patient with cavitary infiltrates, etc
Acid Fast Bacterial (AFB) Stain and Culture: recommended for patient with cavitary infiltrates, etc
Clinical Efficacy
In Patients with Community-Acquired Pneumonia Who Have Been Newly Intubated, Endotracheal Aspirate Has a Better Yield (Yield >50%) of Microbiological Organisms Than Sputum Culture (Ann Am Thorac Soc, 2016) [MEDLINE]
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
Indications for Sputum Gram Stain/Culture (Any of the Following)
Empiric Treatment for Either Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Strong Recommendation, Very Low Quality of Evidence)
Prior Infection with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Especially Prior Respiratory Tract Infection) (Conditional Recommendation, Very Low Quality of Evidence)
These are the Strongest Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
Prior Hospitalization or Receipt of Parenteral Antibiotics within the Last 90 Days (Conditional Recommendation, Very Low Quality of Evidence)
These Factors Increase the Risk of Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Strong Recommendation, Very Low Quality of Evidence)
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
Meta-Analysis of Methicillin-Resistant Staphylococcus Aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia (Clin Infect Dis, 2018) [MEDLINE]: n = 1,563 (22 studies)
For All MRSA Pneumonia Types
Pooled Sensitivity of MRSA Nare Testing for All MRSA Pneumonia Types: 70.9%
Pooled Specificity of MRSA Nare Testing for All MRSA Pneumonia Types: 90.3%
With a 10% Prevalence of Potential MRSA Pneumonia, the Calculated Positive Predictive Value was 44.8% and the Negative Predictive Value was 96.5%
For Community-Acquired Pneumonia (CAP) and Healthcare-Associated MRSA Pneumonia (HCAP)
Pooled Sensitivity of MRSA Nare Testing for All MRSA Pneumonia Types: 85%
Pooled Specificity of MRSA Nare Testing for All MRSA Pneumonia Types: 92.1%
With a 10% Prevalence of Potential MRSA Pneumonia, the Calculated Positive Predictive Value was 56.8% and the Negative Predictive Value was 98.1%
For Ventilator-Associated MRSA Pneumonia
Pooled Sensitivity of MRSA Nare Testing for All MRSA Pneumonia Types: 40.3%
Pooled Specificity of MRSA Nare Testing for All MRSA Pneumonia Types: 93.7%
With a 10% Prevalence of Potential MRSA Pneumonia, the Calculated Positive Predictive Value was 35.7% and the Negative Predictive Value was 94.8%
Data Supporting the Negative Predictive Value of Rapid Methicillin-Resistant Staphylococcus Aureus (MRSA) Testing are Robust (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
Treatment for Methicillin-Resistant Staphylococcus Aureus (MRSA) Pneumonia Can Generally Be Withheld When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Swab is Negative, Especially in Non-Severe Community-Acquired Pneumonia
However, the Positive Predictive Value of Methicillin-Resistant Staphylococcus Aureus (MRSA) Culture is Not as High
Therefore, When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Swab is Positive, Coverage for Methicillin-Resistant Staphylococcus Aureus (MRSA) Pneumonia Should Generally Be Initiated (In the Specific Clinical Situations Noted Below), But Blood/Sputum Cultures Should Be Obtained and Therapy Deescalated if Cultures are Negative
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Indications for Urinary Legionella Antigen Testing
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
Routine Urine Legionella Antigen Testing is Not Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Low Quality of Evidence)
Urine Legionella Antigen Testing is Recommended in Adults with Community-Acquired Pneumonia with Either of the Following
Presence of Either Epidemiologic Risk Factors for Legionella (Conditional Recommendation, Low Quality of Evidence
Association with Legionella Outbreak
Recent Travel
Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Conditional Recommendation, Low Quality of Evidence
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
In Adults with Severe Community-Acquired Pneumonia, Legionella Testing Should Consist of Both of the Following (Conditional Recommendation, Low Quality of Evidence)
Urinary Pneumococcal Antigen Remains Positive for Days After the Start of Antibiotic Treatment
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
Routine Urine Pneumococcal Antigen Testing is Not Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Low Quality of Evidence)
Urine Pneumococcal Antigen Testing is Recommended in Adults with Severe Community-Acquired Pneumonia, as Defined by the Following (Conditional Recommendation, Low Quality of Evidence)
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
Study Examining the Use of Influenza Testing in US Hospitals from 2010-2015 (Chest, 2022) [MEDLINE]: n = 166,268 patients with community-acquired pneumonia (data from 179 Hospitals in the Premier Database)
Only 35.6% of the Community-Acquired Pneumonia Patients were Tested for Influenza
Interestingly, the Rates of Influenza Testing were Low Even During Influenza Season
Influenza-Positive Patients Received Antiviral Agents More Often and Antibacterial Agents Less Often and for Shorter Courses than Influenza-Negative Patients (5.3 vs 6.4 Days; P < 0.001)
Influenza-Positive Patients Receiving Oseltamivir on Hospital Day 1 (n = 2,585) Had a Lower 14-Day In-Hospital Mortality Rate (Adjusted Odds Ratio 0.75; 95% CI: 0.59-0.96), Lower Costs (Adjusted Ratio of Means 0.88; 95% CI: 0.81-0.95), and Shorter Length of Stay (Adjusted Ratio of Means 0.88; 95% CI: 0.84-0.93) vs Patients Receiving Oseltamivir Later or Not at All (n = 1,742)
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
In the Setting of Community-Acquired Pneumonia, When Influenza Viruses are Circulating in the Community, Testing for Influenza with a Rapid Influenza Molecular Assay (i.e. Influenza Nucleic Acid Amplification Test) is Recommended Over a Rapid Influenza Diagnostic Test (i.e. Antigen Test) (Strong Recommendation, Moderate Quality of Evidence
The Benefits of Antiviral Therapy Support Testing of Patients During Periods of High Influenza Activity
During Periods of Low Influenza Activity in the Community, Testing Can Be Considered, But May Not Be Routinely Performed
Recommendations for Diagnostic Testing for Influenza (Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza) (Clin Infect Dis, 2019) [MEDLINE]
Which Patients Should Be Tested for Influenza
Outpatients (including the Emergency Department)
During Influenza Activity (Defined as the Circulation of Seasonal Influenza A/B Viruses in the Local Community)
Clinicians Should Test for Influenza in High-Risk Patients, Including Immunocompromised Patients Who Present with Influenza-Like Illness, Pneumonia, or Nonspecific Respiratory Illness (i.e. Cough without Fever) if the Testing Result Will Influence Clinical Management (A–III)
Clinicians Should Test for Influenza in Patients Who Present with Acute Onset of Respiratory Symptoms with/without Fever, and Either Exacerbation of Chronic Medical Conditions (Asthma, Chronic Obstructive Pulmonary Disease, Heart Failure) or Known Complications of Influenza (Pneumonia) if the Testing Result Will Influence Clinical Management (A-III)
Clinicians Can Consider Influenza Testing for Patients Not at High Risk for Influenza Complications Who Present with Influenza-Like Illness, Pneumonia, or Nonspecific Respiratory Illness (i.e. Cough without Fever) and Who are Likely to Be Discharged Home if the Results Might Influence Antiviral Treatment Decisions or Reduce the Use of Unnecessary Antibiotics, Further Diagnostic Testing, and Time in the Emergency Department, or if the Results Might Influence Antiviral Treatment or Chemoprophylaxis Decisions for High-Risk Household Contacts (C-III)
During Low Influenza Activity without Any Link to an Influenza Outbreak
Clinicians Can Consider Influenza Testing in Patients with Acute Onset of Respiratory Symptoms with/without Fever (Especially for Immunocompromised and High-Risk Patients) (B-III)
Inpatients
During Influenza Activity (Defined as the Circulation of Seasonal Influenza A/B Viruses in the Local Community)
Clinicians Should Test for Influenza on Admission in All Patients Requiring Hospitalization with Acute Respiratory illness (Including Pneumonia) with/without Fever (A-II)
Clinicians Should Test for Influenza on Admission in All Patients with Acute Worsening of Chronic Cardiopulmonary Disease (Asthma, Chronic Obstructive Pulmonary Disease, Coronary Artery Disease, or Heart Failure), as Influenza Can Be Associated with Exacerbation of Underlying Conditions (A-III)
Clinicians Should Test for Influenza on Admission in All Patients Who are Immunocompromised or at High Risk of Complications and Present with Acute Onset of Respiratory Symptoms with/without Fever, as the Manifestations of Influenza in Such Patients are Frequently Less Characteristic than in Immunocompetent Individuals (A-III)
Clinicians Should Test for Influenza in All Patients Who, While Hospitalized, Develop Acute Onset of Respiratory Symptoms, with/without Fever, or Respiratory Distress, without a Clear Alternative Diagnosis (A-III)
During Low Influenza Activity without Any Link to an Influenza Outbreak
Clinicians Should Test for Influenza on Admission in All Patients Requiring Hospitalization with Acute Respiratory Illness, with/without Fever, Who Have an Epidemiological Link to a Patient Diagnosed with Influenza, an Influenza Outbreak or Outbreak of Acute Febrile Respiratory Illness of Uncertain Etiology, or Who Recently Traveled from an Area with Known Influenza Activity (A-II)
Clinicians Can Consider Testing for Influenza in Patients with Acute, Febrile Respiratory Tract illness, Especially Children and Adults Who are Immunocompromised or at High Risk of Influenza Complications, or if the Results Might Influence Antiviral Treatment or Chemoprophylaxis Decisions for High-Risk Household Contacts (B-III)
Nucleic Acid Testing for Respiratory Pathogens
General Comments
Note that in Rhinovirus Infection, Asymptomatic Viral Shedding is Common, Making Multiplex Testing of Unclear Utility (Since No Specific Therapy is Available, Regardless)
Positive Rhinovirus PCR Has Been Reported in 6% of Asymptomatic Adults and 35% of Asymptomatic Children at Any Given Point in Time (mSphere, 2018) [MEDLINE] (Pediatrics, 2014) [MEDLINE] (J Infect Dis, 2018) [MEDLINE]
In Any Patient Presenting with an Acute Respiratory Illness, an Oropharyngeal Swab with Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) Testing for SARS-CoV-2 is Required for the Purpose of Infection Control
Clinical Efficacy
In Patients Hospitalized with Community-Acquired Pneumoniaa, >95% of Patients Received Antibiotics Regardless of Whether They were Found to Be Respiratory Virus Panel Negative or Positive (Am J Infect Control, 2017) [MEDLINE]
Automated Microscopy System, Currently in Development
Recommendations (American Thoracic Society Clinical Practice Guideline for Nucleic Acid-based Testing for Noninfluenza Viral Pathogens in Adults with Suspected Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2021) [MEDLINE]
In Outpatients with Suspected Community-Acquired Pneumonia, Routine Nucleic Acid–Based Testing of Respiratory Samples for Viral Pathogens Other than Influenza (and Presumably SARS-CoV-2) is Not Recommended (Conditional Recommendation, Very Low Quality Evidence)
In Inpatients with Suspected Community-Acquired Pneumonia, Nucleic Acid–Based Testing of Respiratory Samples for Viral Pathogens Other than Influenza (and Presumably SARS-CoV-2) is Recommended Only in the Following Groups (Conditional Recommendation, Very Low Quality Evidence)
Patients with Severe Community-Acquired Pneumonia, as Defined by the Following
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]
Bronchoscopy May Be Indicated for Patient with Community-Acquired Pneumonia Who is Admitted to the Intensive Care Unit (ICU)
Clinical Classification of Pneumonia (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2016 Clinical Practice Guidelines for the Management of HAP/VAP (Clin Infect Dis, 2016) [MEDLINE]
Definition: lung infiltrate associated with clinical evidence that an infiltrate is of an infectious origin (new onset of fever, purulent sputum, leukocytosis, and decline in oxygenation)
Community-Acquired Pneumonia (CAP)
Definition
Pneumonia Which Occurs Either as Outpatient or Within 48 hrs of Hospital Admission
Criteria for Severe Community-Acquired Pneumonia (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
General Comments
Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
Pneumonia Which is Not Incubating at the Time of Hospital Admission and Which Occurs ≥48 hrs After Admission
This Definition Importantly Excludes Any Pneumonia Which is Associated with Mechanical Ventilation
Ventilator-Associated Tracheobronchitis
Definition
Fever (Without Another Recognizable Cause) Associated with New or Increased Sputum Production, Positive Endotracheal Aspirate Culture (>10 to the 6th CFU/mL) Yielding a New Bacteria and No Radiographic Evidence of Pneumonia (Crit Care, 2005) [MEDLINE]
Pneumonia Which Occurs >48 hours After Endotracheal Intubation
Clinical Types of Ventilator-Associated Pneumonia
Early Onset Ventilator-Associated Pneumonia (Within 5 Days of Intubation): usually results from aspiration
Late Onset Ventilator-Associated Pneumonia (After 5 Days of Intubation): usually caused by antibiotic-resistant pathogens and is associated with increased morbidity and mortality
Clinical-Pneumonia Scoring
Clinical Pneumonia Scoring Systems
Pneumonia Severity Index (PSI)
CURB-65
SOFA
Clinical Data
Spanish Cohort Study Comparing Community-Acquired Pneumonia (CAP) Severity Indices in Predicting the In-Hospital Mortality Rate (Am J Respir Crit Care Med, 2017) [MEDLINE]: n = 6874
Overall 6.4% of Patients Died in the Hospital
Most Accurate Predictors: PSI > CURB-65 > mSOFA> CRB > qSOFA > SIRS
qSOFA and CRB (Confusion, Respiratory Rate and Blood Pressure) Criteria Outperformed SIRS and Had Better Clinical Usefulness as Prompt Tools for CAP patients in the Emergency Department
PSI (Pneumonia Severity Index) was More Accurate at Predicting In-Hospital Mortality than mSOFA and CURB-65
Clinical Manifestations
Pulmonary Manifestations
Clinical Efficacy of Symptoms and Signs in the Diagnosis of Community-Acquired Pneumonia (CAP)
Army Medical Center Emergency Department Study of the Diehr Rule for the Prediction of Pneumonia in Patients Presenting with Acute Cough (J Chronic Dis, 1984) [MEDLINE]: n = 1,819
Pneumonia was Radiographically Diagnosed in 2.6% of the Patients
Clinical Decision Rule (Developed in 1,00 of Patients, Validated in 483 Patients)
Rhinorrhea: -2 point
Sore Throat: -1 point
Night Sweats/Myalgias/All-Day Sputum Production: 1 point
Respiratory Rate >25 breaths/min: 2 points
T >100 °F (37.8 °C)
Interpretation of Score
Score of -2 to -3 Points: likelihood of pneumonia was<1%
Score of 3-6 Points: likelihood of pneumonia was 27%
Emergency Department Study of Gennis Rule for the Diagnosis of Pneumonia (J Emerg Med, 1989) [MEDLINE]: n= 308
38% of the Patients Had Radiographic Pneumonia
Symptoms
No Single Symptom or Sign was Reliably Predictive of Pneumonia
Cough was the Most Common Symptom (Present in 86% of Cases, But was Equally Common in Patients without Pneumonia)
Fever was Absent in 31% of Patients with Pneumonia
Abnormal Lung Exam (Rales, Rhonchi, Decreased Breath Sounds, Wheezes, Altered Fremitus, Egophony, Dullness to Percussion) were Found in <50% of the Patients with Pneumonia and 22% of Patients with a Completely Normal Lung Exam Had Pneumonia
Rule Criteria for Obtaining a Chest X-Ray, Based on Presence of At Least One of the Following (97% Sensitivity)
Temperature >100 °F (37.8 °C)
Heart Rate >100 beats/min
Respiratory Rate >20 breaths/min
Emergency Department Prospective Observational Study of Singal Rule for the Diagnosis of Pneumonia (Ann Emerg Med, 1989) [MEDLINE]: n = 255 adults
15.6% of Adult Patients Had Radiographic Pneumonia
Univariate Predictors of Pneumonia were Fever, Cough, Crackles
In Absence of Fever, Cough, and Crackles, Incidence of Pneumonia was Only 4.3%
Emergency Department Study of the Heckerling Rule for the Diagnosis of Pneumonia (Ann Intern Med, 1990) [MEDLINE]: n= 1,436 (3 different emergency departments)
Rule was Developed in 1,134 Patients and Validated in 302 Patients
Rule Criteria for Obtaining a Chest X-Ray (from Stepwise Logistic Regression Model; p <0.001)
Temperature >100 °F (37.8 °C): 1 point
Heart Rate >100 beats/min: 1 point
Crackles: 1 point
Decreased Breath Sounds (Locally): 1 point
Absence of Asthma: 1 point
Interpretation of Score (Pre-Test Probability was 5% in Primary Care and 15% in Emergency Department)
Score 0
Post-Test Probability of Pneumonia (Primary Care): 1%
Post-Test Probability of Pneumonia (Emergency Department): 2%
Likelihood Ratio: 0.12
Score 1
Post-Test Probability of Pneumonia (Primary Care): 1%
Post-Test Probability of Pneumonia (Emergency Department): 3%
Likelihood Ratio: 0.2
Score 2
Post-Test Probability of Pneumonia (Primary Care): 4%
Post-Test Probability of Pneumonia (Emergency Department): 11%
Likelihood Ratio: 0.7
Score 3
Post-Test Probability of Pneumonia (Primary Care): 8%
Post-Test Probability of Pneumonia (Emergency Department): 22%
Likelihood Ratio: 1.6
Score 4
Post-Test Probability of Pneumonia (Primary Care): 27%
Post-Test Probability of Pneumonia (Emergency Department): 56%
Likelihood Ratio: 7.2
Score 5
Post-Test Probability of Pneumonia (Primary Care): 47%
Post-Test Probability of Pneumonia (Emergency Department): 75%
Likelihood Ratio: 17
Rule Had a Receiver Operating Characteristic (ROC) Area 0.82
In the Validation Sets, the Rule Discriminated Pneumonia and Non-Pneumonia with ROC Areas of 0.82 and 0.76 (After Adjusting for Differences in Disease Prevalence)
Comparative Prospective Study of Diehr/Gennis/Heckerling/Singal Rules with Physician Judgement for the Diagnosis of Pneumonia in Emergency Department and Outpatient Settings (Ann Emerg Med, 1991) [MEDLINE]: n = 290
All Patients Had an Acute Cough and Fever, Hemoptysis, or Sputum Production
Abnormal Pulmonary Exam Findings
Findings Consistent with Consolidation (Alveolar Filling Process)
Presence of Pleural Effusion at Emergency Department Presentation with Pneumonia Predicts an Increasing Likelihood of Being Admitted, Longer Hospital Stay, and Increased 30-Day Mortality Rate (Chest, 2016) [MEDLINE]
Preferences for home vs hospital care among low-risk patients with community-acquired pneumonia. Arch Intern Med 1996; 156:1565–71 [MEDLINE]
A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997 Jan 23;336(4):243-50 [MEDLINE]
The cost of treating community-acquired pneumonia. Clin Ther. 1998 Jul-Aug;20(4):820-37 [MEDLINE]
Risk factors for venous thromboembolism in hospitalized patients with acute medical illness: analysis of the MEDENOX Study. Arch Intern Med 2004; 164:963–8 [MEDLINE]
Validation of predictive rules and indices of severity for community acquired pneumonia. Thorax 2004; 59:421–7 [MEDLINE]
Risk factors of treatment failure in community acquired pneumonia: implications for disease outcome. Thorax 2004;59:960-965 [MEDLINE]
Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. Clin Infect Dis. 2007 Mar 1;44 Suppl 2:S27-72 [MEDLINE]
CDC Etiology of Pneumonia in the Community (EPIC) Study. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373(5):415-27. doi: 10.1056/NEJMoa1500245. Epub 2015 Jul 14 [MEDLINE]
Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. 2016 Sep 1;63(5):e61-e111. doi: 10.1093/cid/ciw353. Epub 2016 Jul 14 [MEDLINE]
Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67. doi: 10.1164/rccm.201908-1581ST [MEDLINE]
Epidemiology
A risk score for identifying methicillin-resistant Staphylococcus aureus in patients presenting to the hospital with pneumonia. BMC Infect Dis. 2013 Jun 6;13:268. doi: 10.1186/1471-2334-13-268 [MEDLINE]
Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease. Thorax. 2015 Oct;70(10):984-9. doi: 10.1136/thoraxjnl-2015-206780 [MEDLINE]
Liver Cirrhosis and Diabetes Mellitus Are Risk Factors for Staphylococcus aureus Infection in Patients with Healthcare-Associated or Hospital-Acquired Pneumonia. Pulm Med. 2016;2016:4706150. doi: 10.1155/2016/4706150 [MEDLINE]
Risk Factors for Community-Acquired Pneumonia in Adults: A Systematic Review of Observational Studies. Respiration. 2017;94(3):299-311. doi: 10.1159/000479089 [MEDLINE]
Undiagnosed Diabetes Mellitus in Community-Acquired Pneumonia: A Prospective Cohort Study. Clin Infect Dis. 2017 Nov 29;65(12):2091-2098. doi: 10.1093/cid/cix703 [MEDLINE]
Risk Factors for Legionella longbeachae Legionnaires’ Disease, New Zealand. Emerg Infect Dis. 2017 Jul;23(7):1148-1154. doi: 10.3201/eid2307.161429 [MEDLINE]
Risk of Infection in Type 1 and Type 2 Diabetes Compared With the General Population: A Matched Cohort Study. Diabetes Care. 2018 Mar;41(3):513-521. doi: 10.2337/dc17-2131 [MEDLINE]
Differences between diabetic and non-diabetic patients with community-acquired pneumonia in primary care in Spain. BMC Infect Dis. 2019 Nov 15;19(1):973. doi: 10.1186/s12879-019-4534-x [MEDLINE]
The Glycemic Gap and 90-Day Mortality in Community-acquired Pneumonia. A Prospective Cohort Study. Ann Am Thorac Soc. 2019 Dec;16(12):1518-1526. doi: 10.1513/AnnalsATS.201901-007OC [MEDLINE]
Methicillin-resistant Staphylococcus aureus pneumonia in diabetics: a single-center, retrospective analysis. Chin Med J (Engl). 2019 Jun 20;132(12):1429-1434. doi: 10.1097/CM9.0000000000000270 [MEDLINE]
Diabetes and the Risk of Infection: A National Cohort Study. Diabetes Metab J. 2019 Dec;43(6):804-814. doi: 10.4093/dmj.2019.0071 [MEDLINE]
Effect of tobacco smoking on the risk of developing community acquired pneumonia: A systematic review and meta-analysis. PLoS One. 2019 Jul 18;14(7):e0220204. doi: 10.1371/journal.pone.0220204. eCollection 2019 [MEDLINE]
Hospital-acquired Legionella pneumonia outbreak at an academic medical center: Lessons learned. Am J Infect Control. 2021 Aug;49(8):1014-1020. doi: 10.1016/j.ajic.2021.02.013 [MEDLINE]
Risk of sepsis and pneumonia in patients initiated on SGLT2 inhibitors and DPP-4 inhibitors. Diabetes Metab. 2022 Jun 23;101367. doi: 10.1016/j.diabet.2022.101367 [MEDLINE]
Metformin Use Is Associated With Lower Mortality in Veterans With Diabetes Hospitalized With Pneumonia. Clin Infect Dis. 2022 Dec 28;ciac900. doi: 10.1093/cid/ciac900 [MEDLINE]
Microbiology
Etiology of community-acquired pneumonia treated in an ambulatory setting. Resp Medicine 2005; 99:60
A comparative study of community-acquired pneumonia patients admitted to the ward and the ICU. Chest 2008; 133:610
Microbial aetiology of community-acquired pneumonia and its relation to severity. Thorax 2011; 66:340
EPIC Study. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373(5):415-27. doi: 10.1056/NEJMoa1500245 [MEDLINE]
Diagnosis
General
Contributions of symptoms, signs, erythrocyte sedimentation rate, and C-reactive protein to a diagnosis of pneumonia in acute lower respiratory tract infection. Br J Gen Pract. 2003;53:358–64 [MEDLINE]
Use of tracheal aspirate culture in newly intubated patients with community-onset pneumonia. Ann Am Thorac Soc 2016;13:376–381 [MEDLINE]
Impact of respiratory virus molecular testing on antibiotic utilization in community-acquired pneumonia. Am J Infect Control 2017;45: 1396–1398 [MEDLINE]
The Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis With Antimicrobial Stewardship Implications. Clin Infect Dis. 2018 Jun 18;67(1):1-7. doi: 10.1093/cid/ciy024 [MEDLINE]
Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza. Clin Infect Dis. 2019;68(6):e1 [MEDLINE]
Nucleic Acid-based Testing for Noninfluenza Viral Pathogens in Adults with Suspected Community-acquired Pneumonia. An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2021;203(9):1070 [MEDLINE]
Prediction of pneumonia in outpatients with acute cough—a statistical approach. J Chronic Dis. 1984;37:215–25 [MEDLINE]
Clinical criteria for the detection of pneumonia in adults: guidelines for ordering chest roentgenograms in the emergency department. J Emerg Med. 1989;7:263–8 [MEDLINE]
Decision rules and clinical prediction of pneumonia: evaluation of low-yield criteria. Ann Emerg Med. 1989;18:13–20 [MEDLINE]
Clinical prediction rule for pulmonary infiltrates. Ann Intern Med. 1990;113:664–70 [MEDLINE]
Comparison of physician judgment and decision aids for ordering chest radiographs for pneumonia in outpatients. Ann Emerg Med. 1991;20:1215–9 [MEDLINE]
Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination. JAMA. 1997;278:1440–5 [MEDLINE]
Predicting pneumonia in adults with respiratory illness. Am Fam Physician. 2007 Aug 15;76(4):560-2 [MEDLINE]
High serum procalcitonin concentrations in patients with sepsis and infection. Lancet 1993; 341:515–8 [MEDLINE]
Accuracy of procalcitonin for sepsis diagnosis in critically ill patients: systematic review and meta-analysis. Lancet Infect Dis. 2007;7(3):210 [MEDLINE]
Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2012 Sep 12;(9):CD007498. doi: 10.1002/14651858.CD007498.pub2 [MEDLINE]
Procalcitonin to guide initiation and duration of antibiotic treatment in acute respiratory infections: an individual patient data meta‐analysis. Clin Infect Dis 2012: 55(5):651–662 [MEDLINE]
An ESICM systematic review and meta‐analysis of procalcitonin‐guided antibiotic therapy algorithms in adult critically ill patients. Intensive Care Med 2012: 38(6):940–949 [MEDLINE]
Procalcitonin‐guided therapy in intensive care unit patients with severe sepsis and septic shock—a systematic review and meta‐analysis. Crit Care 2013: 17(6):R291 [MEDLINE]
Procalcitonin‐guided antibiotic therapy: a systematic review and meta‐analysis. J Hosp Med 2013: 8(9):530–540 [MEDLINE]
Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta‐analysis. Lancet Infect Dis 2013: 13(5):426–435 [MEDLINE]
Procalcitonin as a diagnostic marker in differentiating parapneumonic effusion from tuberculous pleurisy or malignant effusion. Clin Biochem. 2013;46(15):1484 [MEDLINE]
Biomarkers: what is their benefit in the identification of infection, severity assessment, and management of community-acquired pneumonia? Infect Dis Clin North Am. 2013 Mar;27(1):19-31. Epub 2012 Dec 6 [MEDLINE]
Procalcitonin guided antibiotic therapy of acute exacerbations of asthma: a randomized controlled trial. BMC Infect Dis. 2013;13:596. Epub 2013 Dec 17 [MEDLINE]
Procalcitonin testing to guide antibiotic therapy for the treatment of sepsis in intensive care settings and for suspected bacterial infection in emergency department settings: a systematic review and cost‐effectiveness analysis. Health Technol Assess 2015: 19(96):v–xxv, 1–236 [MEDLINE]
Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial. Lancet Infect Dis. 2016 Jul;16(7):819-27. doi: 10.1016/S1473-3099(16)00053-0. Epub 2016 Mar 2 [MEDLINE]
Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016 Sep 1;63(5):e61-e111. doi: 10.1093/cid/ciw353. Epub 2016 Jul 14 [MEDLINE]
Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial. Lancet Infect Dis. 2016 Jul;16(7):819-27. doi: 10.1016/S1473-3099(16)00053-0. Epub 2016 Mar 2 [MEDLINE]
Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2017 Oct 12;10:CD007498. doi: 10.1002/14651858.CD007498.pub3 [MEDLINE]
Procalcitonin as a marker of etiology in adults hospitalized with community-acquired pneumonia. Clin Infect Dis 2017;65:183–190 [MEDLINE]
Effect of procalcitonin-guided antibiotic treatment on mortality in acute respiratory infections: a patient level meta-analysis. Lancet Infect Dis. 2018 Jan;18(1):95-107. doi: 10.1016/S1473-3099(17)30592-3 [MEDLINE]
Low procalcitonin, community acquired pneumonia, and antibiotic therapy. Lancet Infect Dis 2018;18:496–497 [MEDLINE]
ProACT Trial. Procalcitonin-Guided Use of Antibiotics for Lower Respiratory Tract Infection. N Engl J Med. 2018 Jul 19;379(3):236-249. doi: 10.1056/NEJMoa1802670 [MEDLINE]
Severity assessment tools to guide ICU admission in community-acquired pneumonia: systematic review and meta-analysis. Intensive Care Med 2011;37:1409–1420 [MEDLINE]
New Sepsis Definition (Sepsis-3) and Community-acquired Pneumonia Mortality: A Validation and Clinical Decision-making Study. Am J Respir Crit Care Med. 2017 Jun 14. doi: 10.1164/rccm.201611-2262OC [MEDLINE]
Prevention
Facilitating influenza and pneumococcal vaccination through standing orders programs. JAMA 2003; 289:1238 [MEDLINE]
