Severity of disease and mortality for hospitalized patients with community-acquired viral pneumonia compared to patients with community-acquired bacterial pneumonia

Abstract

Background: There exists a large body of literature to help identify, diagnose, treat, and manage community-acquired pneumonia (CAP). Despite this, there is little data that directly compares the clinical syndromes and complications of pure bacterial pneumonia to pure viral pneumonia. Our study compares the clinical presentation, morbidity and mortality of viral vs. bacterial etiologies of CAP. Methods: This was a secondary data analysis of the Community-Acquired Pneumonia Organization (CAPO) international study database. Data was collected concerning patient demographics, physical examination findings, laboratory findings, radiological findings, severity of illness, and clinical outcomes and stratified according to the two study groups, CAVP and CABP. A microbiological diagnosis of CABP was based on the isolation of a bacterium from a respiratory sample, blood culture and/or identification of a urinary antigen for Streptococcus or Legionella; microbiological diagnosis of CAVP was based on polymerase chain reaction or antigen detection from respiratory samples. Results: Our study included 1,913 patients. Of these, 286 (15.0%) had viral infection, while 1,627 (85.0%) had CAVP. We found that bacterial CAP patients are older, more frequently male, and suffer from a higher proportion of comorbidities when compared to viral CAP patients. Comparison of physical exam findings and laboratory values failed to find a clinically significant difference between bacterial and viral CAP patients. When comparing severity of illness, bacterial CAP patients had greater frequency of PSI ≥ class IV; however, viral CAP patients more frequently needed ICU admission, ventilator support, vasopressor support, and had higher rate of in hospital mortality. Conclusions: Our study confirms the extreme difficulty differentiating CABP from CAVP using demographics, physical exam, or x-ray findings. We found no major clinical or laboratory findings distinguishing CABP from CAVP. The increased severity of illness of CAVP compared to bacterial etiologies shows that PSI scores may not be an accurate indicator of severity of disease. More studies are needed to identify the best process of care for patients with CAP, including the potential benefits of routine respiratory viral panel testing and empiric antiviral therapy.

Prepandemic viral community‐acquired pneumonia: Diagnostic sensitivity and specificity of nasopharyngeal swabs and performance of clinical severity scores

“…Regarding the PSI, our results do not confirm the data from Kim et al, 15 who observed no differences in this score, between viral and bacterial CAP, nor in mortality between these two groups (15% and 16%, respectively). However, our results agree with those from other authors who evaluated disease severity in the setting of viral versus bacterial CAP 35 . Their results showed that bacterial CAP more frequently had PSI ≥ class IV, despite the fact that viral CAP significantly showed higher frequencies of ICU admission, intubation, and in hospital mortality, concluding that PSI scores cannot be used to accurately predict the outcome in viral CAP 35 …”

“…However, our results agree with those from other authors who evaluated disease severity in the setting of viral versus bacterial CAP. 35 Their results showed that bacterial CAP more frequently had PSI ≥ class IV, despite the fact that viral CAP significantly showed higher frequencies of ICU admission, intubation, and in hospital mortality, concluding that PSI scores cannot be used to accurately predict the outcome in viral CAP. 35 The low number of deaths and patients per PSI and CURB-65 scores risk classes, especially in the viral CAP group, are limitations of this study to confirm our findings regarding the usefulness of the severity scores, especially in the viral etiology.…”

“…However, our results agree with those from other authors who evaluated disease severity in the setting of viral versus bacterial CAP. 35 Their results showed that bacterial CAP more frequently had PSI ≥ class IV, despite the fact that viral CAP significantly showed higher frequencies of ICU admission, intubation, and in hospital mortality, concluding that PSI scores cannot be used to accurately predict the outcome in viral CAP. 35 …”

“…35 Their results showed that bacterial CAP more frequently had PSI ≥ class IV, despite the fact that viral CAP significantly showed higher frequencies of ICU admission, intubation, and in hospital mortality, concluding that PSI scores cannot be used to accurately predict the outcome in viral CAP. 35 The low number of deaths and patients per PSI and CURB-65 scores risk classes, especially in the viral CAP group, are limitations of this study to confirm our findings regarding the usefulness of the severity scores, especially in the viral etiology. In addition, comparison of NP and sputum results with BAL samples was not possible because the latter were only obtained in three patients in whom this invasive technique was clinically indicated.…”