Comparison of clinical characteristics and outcomes between respiratory syncytial virus and influenza-related pneumonia in China from 2013 to 2019

Abstract

This study aims to compare clinical characteristics and severity between adults with respiratory syncytial virus (RSV-p) and influenza-related pneumonia (Flu-p). A total of 127 patients with RSV-p, 693 patients with influenza A-related pneumonia (FluA-p), and 386 patients with influenza B-related pneumonia (FluB-p) were retrospectively reviewed from 2013 through 2019 in five teaching hospitals in China. A multivariate logistic regression model indicated that age ≥ 50 years, cerebrovascular disease, chronic kidney disease, solid malignant tumor, nasal congestion, myalgia, sputum production, respiratory rates ≥ 30 beats/min, lymphocytes < 0.8×10⁹/L, and blood albumin < 35 g/L were predictors that differentiated RSV-p from Flu-p. After adjusting for confounders, a multivariate logistic regression analysis confirmed that, relative to RSV-p, FluA-p (OR 2.313, 95% CI 1.377-3.885, p = 0.002) incurred an increased risk for severe outcomes, including invasive ventilation, ICU admission, and 30-day mortality; FluB-p (OR 1.630, 95% CI 0.958-2.741, p = 0.071) was not associated with increased risk. Some clinical variables were useful for discriminating RSV-p from Flu-p. The severity of RSV-p was less than that of FluA-p, but was comparable to FluB-p.

Keywords: Clinical characteristic; Influenza virus; Outcome; Pneumonia; Respiratory syncytial virus.

Fig. 1

Screening algorithm of patients hospitalized with RSV-p and Flu-p. The medical records of 3375 patients with RSV or influenza RNA positive were reviewed. A total of 127 laboratory-confirmed RSV-p patients and 1079 Flu-p patients (including 693 FluA-p patients and 386 FluB-p patients) were included

Fig. 2

Distribution of patients with RSV-p and Flu-p by months. RSV-p and Flu-p had similar seasonality, both covered from October to May

Fig. 3

Forest plot of predictors for RSV-p. Age ≥ 50 years, cerebrovascular disease, chronic kidney disease, solid malignant tumor, nasal congestion, respiratory rates ≥ 30 beats/min, and blood albumin < 35 g/L favored RSV-p; myalgia, sputum production, and lymphocytes < 0.8×10⁹/L favored Flu-p

Fig. 4

Comparison of severity and outcomes by virus types (reference: RSV-p). Compared to RSV-p, FluA-p was associated with increased risks for invasive ventilation, ICU admission, and 30-day mortality; the risks for invasive ventilation, ICU admission, and 30-day mortality of FluB-p were not significantly different with RSV-p

Fig. 5

Survival rate of patients hospitalized with FluA-p, FluB-p, and RSV-p (censored at 30 days after admission). After adjustment for confounders, the 30-day mortality of FluA-p patients was significantly higher than that of RSV-p patients, while the 30-day mortality of patients with FluB-p and RSV-p was similar