The Importance of Viral Etiology in Hospitalized Patients with
Community Acquired Pneumonia in Jefferson County
Martin Gnoni MD, Swetha Kadali, MD, Jorge Perez, MD, Rehab Abdelfattah, MD, MPH, Daniel Curran, MD, Murali Kolikonda, MD, Srinivas Uppatla, MD, Sridivya
Peddapalli, MD, Robert Kelley, PhD, Paula Peyrani, MD
ABSTRACT
RESULTS
Background: Community Acquired Pneumonia (CAP) is a leading cause of
infectious disease-related death in the world. Traditionally CAP has been
considered primarily a bacterial infection. A few studies have addressed
the role of viruses as etiologic agents of CAP. The pathogenic role of
rhinovirus isolated from clinical samples in hospitalized patients with
lower respiratory tract infections (LRTIs) is not clear in the literature. The
objective of this study is to determine the incidence of respiratory viruses
in hospitalized adult patients with CAP and the possible role of rhinovirus
as a pathogen.
Methods: Hospitalized patients with CAP from the Rapid Empiric
Treatment with Oseltamivir Study (RETOS) database were included in the
study. A sub analysis was made of the patients with a viral organism
identified by PCR. Incidence of organism isolation calculated.
Results: A total of 262 viral CAP patients were identified in the RETOS
database. Influenza was the most common virus isolated overall (n=112,
43%). The second most common virus was rhinovirus(n=67, 26%) . In
55(21%) of the viral CAP patients, rhinovirus was the only organism
isolated.
Discussion: We conclude that because rhinovirus was the sole isolate in a
high percentage of viral-CAP patients, rhinovirus may be considered a real
pathogen in hospitalized adult patients with CAP. This study supports the
need for an extensive microbiologic work up in patients with CAP for both
bacterial and viral etiologies.
• From a total of 800 hospitalized patients with CAP identified in the
RETOS database 262 (32%) were identified as viral CAP (v-CAP) (Table 1,
Figure 1).
INTRODUCTION
Community Acquired Pneumonia (CAP) is a leading cause of infectious
disease-related death in the world [1] despite improvements in antibiotic
and supportive treatment. Traditionally CAP has been considered primarily
a bacterial infection. Until recently few studies have addressed the role of
viruses as etiologic agents of CAP probably due to the poor sensitivity and
specificity of diagnostic assays along with the lack of available biomolecular
tests (PCR) [2]. The pathogenic role of rhinovirus isolated from clinical
samples in hospitalized patients with lower respiratory tract infections
(LRTIs) including CAP is controversial in the literature [3-5]. The objective of
this study is to determine the incidence of respiratory viruses in
hospitalized adult patients with CAP and the possible role of rhinovirus as a
pathogen.
MATERIALS AND METHODS
Hospitalized patients with CAP from the Rapid Empiric Treatment with
Oseltamivir Study (RETOS) database were included in the study. A sub
analysis was made of the patients with a viral organism identified by PCR.
Incidence of organism isolation was calculated.
Definitions:
CAP: The presence of criteria A plus at least one of the following
criteria :
•X-ray evidence of new pulmonary infiltrate (at time of
hospitalization )
•New or increased cough with/without sputum production
•Fever > 37.8 oC (100.0oF) or hypothermia <35.6oC (96.0oF)
•Changes in WBC (leukocytosis, left shift or leukopenia)
Viral CAP(v-CAP):The presence of CAP plus a positive PCR for one of
the viruses included in the viral panel (multiplex PCR)
RESULTS (con’t)
CONCLUSIONS (con’t)
• There are some limitations of this study. In a considerable number of our
patients rhinovirus was the only organism isolated. However we cannot
ignore the fact that we utilized nasopharyngeal swabs in most of our
patients for diagnosis so we were unable to distinguish if the viral
etiology was a real pathogen or a predisposing condition for a
superimposed viral/bacterial infection that was not detected.
• 29 (11%) v-CAP were admitted to ICU (ICU-v-CAP)
• 233 (89%) v-CAP were admitted to the ward (W-v-CAP)
• We also identified a significant number of viral CAP in our cohort that
has risk factors for HCAP. The significance of the association between
risk factors for HCAP and viral CAP remains unknown.
• 11(38%) ICU-v-CAP were associated with coinfections
• 35 (15%) W-v- CAP were associated with coinfections
• A strength of this study is that it is one of the few multicenter studies
addressing the viral etiology of CAP.
• Influenza was the most common virus isolated (10 out of 29 -34%- ICU-vCAP , and 101 out of 233 - 43% - W-v-CAP).
• Another strength is the use of molecular techniques for diagnosis of viral
respiratory infections.
• The second most common virus was rhinovirus (9 out of 29 -31%- ICU-vCAP and 58 out of 233 -25%- W–v-CAP).
• In 55 (21%) of the v-CAP patients, rhinovirus was the only organism
isolated.
Figure 1: Overall percentage of virus isolated in patients with CAP
• We conclude that one third of adult hospitalized patients with CAP are
infected with a respiratory virus, with influenza and rhinovirus being the
two most common.
• The patients with more severe disease that are admitted to the ICU are
more likely to have a dual infection.
Table 1: Characteristics and outcomes of hospitalized patients with LRTI
and HRV detection
Variable
Age, mean
Male
Chronic hemodialysis
COPD
Diabetes
Chronic heart failure
Cerebrovascular disease
Liver disease
Kidney disease
Previous hospitalization prior 90 days
Antibiotic therapy prior 90 days
Nursing home
Multilobar infiltrates
PSI score, mean
Value
n (%)
62
116 (44%)
7 (3%)
113 (43%)
95 (36%)
69 (26%)
31 (12%)
20 (8%)
54 (20%)
63 (24%)
45 (17%)
13 (5%)
137 (52%)
84
CONCLUSIONS
• Viruses are a common etiology of CAP either in the ward or ICU.
• Because rhinovirus was the sole isolate in a high percentage of viral-CAP
patients, rhinovirus may be considered a real pathogen in hospitalized
adult patients with CAP.
• Influenza and Rhinovirus were the two most common viruses isolated in
our cohort.
• The severity of the ICU-v-CAP patients can be explained by the fact that
one third of the ICU-v-CAP are associated with coinfections.
REFERENCES
• Since most of the respiratory viruses can be transmitted from patient to
patient, our study suggests that one out of three adult hospitalized
patients with CAP may need some sort of respiratory and/or contact
isolation in Jefferson County.
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• This study also supports the need for an extensive microbiologic work up
in patients with CAP (ICU-CAP and W-CAP) for both bacterial and viral
etiologies in order to target therapy and improve clinical outcomes.
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it was the only organism isolated.
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