Host characteristics predict outcome among adult patients admitted by severe acute respiratory infection

Abstract

Background: Except for influenza pandemics, different observational studies have failed to demonstrate differences in mortality between various etiologies in adult patients hospitalized for respiratory infections. Aim: To compare clinical and mortality differences between different viral pathogens associated with severe acute respiratory infections (SARI) in hospitalized adults. Material and Methods: One-year prospective study in a sentinel center. We included 132 patients with SARI hospitalized for any of the nine viruses under study by PCR. Clinical variables were compared, excluding cases of coinfection. Results: A viral coinfection was identified in 12% and influenza infection in 56% of cases. Eighty percent of patients were aged ≥ 65 years, with a high frequency of comorbidities, 27% were bedridden. Twenty four percent were admitted to critical care units, 20% required ventilatory assistance and 16% died. Cases occurred throughout the year, with an expected seasonal peak between autumn and spring and a predominance of infections not associated with influenza during summer months. In the multivariate analysis, only being bedridden was significantly associated with mortality at discharge (Odds ratio 23.46; 95% confidence intervals 3.33-165.12, p < 0.01), without association with age, comorbidity, viral pathogen involved, laboratory parameters, clinical presentation or CURB65 score. No major clinical dissimilarities were found between different viral pathogens. Conclusions: In our series of patients, mostly elderly, only bedridden status was significantly associated with mortality at discharge in patients hospitalized for SARI. Viral pathogens were not relevant.

Burden of influenza in the elderly: a narrative review

“…Risk factors for influenza-related mortality in the elderly are age and comorbidities (including immunosuppression, chronic cardiovascular and liver diseases) [33,36]. Another major determinant might rely in the functional status, as a daily walking time of at least 1 h has been associated with a lower risk of pneumonia mortality [37 ▪ ,38]. Among circulating virus strains, the elderly are distinguished by influenza-attributable excess mortality due to A(H3N2) compared with A(H1N1) or B viruses [24,39,40].…”