Viral aetiology and clinical outcomes in hospitalised infants presenting with respiratory distress.

Falkenstein-Hagander, Kathy; MÃ¥nsson, Ann-Sofie; Redmo, Johan; Nilsson Wimar, Percy; Widell, Anders

AIM To determine the prevalence of various types of viruses in infants hospitalised due to respiratory distress, compare molecular diagnostic tests and evaluate symptom severity. METHODS All 136 nasopharyngeal aspirates from infants hospitalised for respiratory distress over a 9-month period were analysed for virus type by in-house respiratory syncytial virus (RSV) polymerase chain reaction (PCR) microarray-based and/or Luminex-based multiplex molecular tests. Medical records were reviewed retrospectively for clinical data. RESULTS Viral aetiology was confirmed in 126 subjects (92.6%) with 26 infected by more than one virus. RSVA/B was the most common (50.9%), followed by entero/rhinovirus (21.6%), human metapneumovirus (10.5%), parainfluenza virus (5.9%) and influenza (3.3%). RSV-infected infants had significantly lower saturation levels (89% versus 92%, p < 0.001), higher demand for oxygen (42.7% versus 21.6%, p = 0.021) and fluids (28% versus 9.8%; p = 0.014) and longer hospital stays (4 versus 3 days, <0.001) than other viruses. Luminex assays gave repeatable, slightly less sensitive results than in-house RSV PCR. Microarray-based assays were more sensitive, however, producing some unrepeatable results. CONCLUSION Respiratory syncytial virus dominates as the viral cause in hospitalised infants with respiratory distress in Sweden during the winter season, resulting in a clinical course that is significantly more severe. The multiplex assays produced reasonably concordant results.