Association between nutritional status and severity of RSV-associated lower respiratory tract infection: a retrospective study in hospitalised children under 5 years of age.

Introduction: Severe lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV) is a major cause of respiratory morbidity in children. Nutritional status is hypothesised to influence the severity of RSV infection, affecting clinical outcomes. Objective: To evaluate the association between malnutrition and the severity of RSV-related LRTI in children. Methods: A retrospective study was conducted at Naresuan University Hospital, including children under 5 years of age diagnosed with RSV LRTI between January 2014 and December 2018. Nutritional status was assessed using Z-scores for wasting (weight-for-height), underweight (weight-for-age), stunting (height-for-age) and both undernutrition and overnutrition (body mass index). Data were analysed using STATA V.18. Univariate analysis used t-test and χ Results: A total of 250 children met the inclusion criteria, with 36 (14.4%) classified as having severe RSV LRTI and 214 (85.6%) as non-severe cases. Among those with severe RSV-related LRTI, 16 (44.4%) were male and 20 (55.6%) were female, whereas in the non-severe group, 119 (55.6%) were male and 95 (44.4%) were female. Multivariable analysis revealed that severe wasting (aOR=3.70; 95% CI 1.01 to 13.55; p=0.048) and severe underweight (aOR=9.09; 95% CI 2.62 to 31.50; p=0.001) were strongly correlated with severe RSV LRTI. Discussion: Severe wasting and severe underweight are significant risk factors for severe RSV LRTI in children. These findings suggest that improving nutritional status may help reduce the severity of RSV LRTI.