Pneumococcal Pneumonia and Influenza A Pneumonia: A Comparative Study

Abstract

Introduction: Pneumonia is defined as an infection of the lung
parenchyma. The most common overall pathogen is Streptococcus
pneumoniae, however, influenza virus is also common
and is associated with severe disease. The viral etiology of
pneumonia is underdiagnosed. We analyzed and compared
the clinical, laboratory and radiological data, severity at admission
and outcome of patients with influenza A pneumonia
and pneumococcal pneumonia.
Methods: Retrospective analysis of clinical and epidemiological
data of hospitalized patients between October 1, 2013 and
March 31, 2014, in a medium-sized Hospital, with confirmed
influenza A pneumonia and/or pneumococcal pneumonia.
Results: We identified 40 cases of pneumococcal pneumonia
and 40 cases of influenza A pneumonia. In the viral pneumonia
group the mean age was 65.8 years (vs 74.6 (p = 0.017)).
Pneumococcal pneumonia patients had higher Charlson comorbidities
index (median 7 vs 4, p < 0.001), higher CURB-65
(p = 0.001) and white blood cells count (15273 vs 9656 / μL, p
< 0.001) and C-reactive protein at admission (191 vs 115 mg /
L, p = 0.014) were higher. In viral cases there was more need
to escalate level of medical care (43% vs 18%, p = 0.015), with
no significant difference in in-hospital mortality.
Conclusion: We obtained the same number of patients in each
group, which reveals a higher prevalence of influenza than we
normally expect. Compared to patients with pneumococcal
pneumonia, patients with viral pneumonia were younger and
had a lower comorbidities index; on admission, they presented
lower inflammatory parameters and CURB-65; the need to
escalate care was higher, however mortality was not significantly
different.