Nutritional status and clinical evolution of hospitalized Chilean infants with infection by respiratory syncytial virus (RSV)

Respiratory syncycial virus (RSV) is the first cause of acute lower respiratory tract infection in Chilean infants. A significant impact of nutrition on clinical course of these infections has been described. In order to analyze the association between nutritional status (NS) and clinical course of infants hospitalized with acute lower respiratory tract infection due to RSV, 130 infants (mean age 5.8 +/- 4.9 m) without chronic diseases, admitted to hospital with confirmed RSV infection, were studied. Clinical course of disease was assessed (hospitalization days and days with oxygen therapy) according to nutritional status on admission (weight/length (W/L), ratio, arm muscle area, lymphocyte count and albumin), antropometrics changes, and hospital dietary intake. On admission prevalence of malnutrition by W/L (z score) was 1%, 14% overweight and 8% were obese. Median value of hospitalization days was 5 d (2-29 d) and days receiving oxygen was 3 d (0-19 d). Longer admission were observed in fasted patients than in those who were fed everyday (Wilcoxon and Log-rank test, 8 d vs 5 d; P < 0.01). Obese children (Wilcoxon and Log-rank test, 5 d vs. 3d in normal patients; P < 0.05), and patients not fed enterally (Wilcoxon and Log-rank test, 7 d vs. 3 d; P < 0.01) required oxygen for longer time. Fasting and severity of illness (Tal score) were correlated variables (X2 0.001). The multivariate analysis showed an association of Tal score and NS on admission, with days receiving oxygen therapy. We conclude that obesity is a risk factor for worse clinical course of acute lower respiratory tract infection in Chilean infants with RSV infection and without chronic disease.