Age-Dependent Clinical Characteristics of Acute Lower Respiratory Infections in Young Hospitalized Children with Respiratory Syncytial Virus Infection

INTRODUCTION: Human respiratory syncytial virus (HRSV) is the most common cause of acute lower respiratory infection (LRTI) in children. The main clinical manifestations are fever, cough, wheezing, and intercostal retractions. Its age-dependent clinical characteristics remain to be defined. OBJECTIVE: We investigated whether HRSV caused any age-related differences in clinical manifestations of LRTI. METHODS: We enrolled 130 hospitalized children with LRTI caused by HRSV. These were stratified into four age groups. The main signs and symptoms and rates thereof were compared across the four age groups. RESULTS: The incidence of pneumonia was the same in all four age groups. Patients in the 1–6 months old group experienced fever and the highest body temperature ≥ 38.5°C less frequently than patients in other age groups.The frequency of fever increased with age among the patients under 24 months old. Children over 12 months old experienced less wheezing, tachypnoea, hypoxia, and intercostal retractions than children in the 1–6 months old group. CONCLUSION: HRSV caused age-related differences in clinical manifestations of LRTI. Reduced fever responses among patients 6 months old and younger during RSV infection does not implicate less severity, wheezing, tachypnoea, hypoxia, and intercostal retractions are the main clinical manifestations, Fever responses were enhanced with advancing age among children under 24 months old.