title: Respiratory syncytial virus infections in hospitalized infants: association between viral load, virus subgroup, and disease severity.
abstract: The relationships between host factors, virus strain, viral load, and illness severity in respiratory syncytial virus (RSV)-induced bronchiolitis are poorly defined. These relationships were evaluated prospectively in 81 previously healthy infants hospitalized with RSV bronchiolitis. Disease severity was determined by the respiratory rate, the duration of hospitalization, and whether patients during their hospitalization required pediatric intensive care unit admission or mechanical ventilation. RSV typing into subgroup A and B was obtained by RT-PCR-hybridization assay. The nasopharyngeal RSV viral loads were measured by real-time quantitative RT-PCR. Disease severity correlated significantly with the presence of risk factor (estimated gestational age < 37 weeks and/or birth weight < 2,500 g) and with chronologic age <or= 28 days at time of sample collection. The results revealed significant association between disease severity and nasopharyngeal RSV viral load. Analysis also showed that disease severity was not associated significantly with RSV subgroup. Thus, RSV disease severity is likely to be determined by an interplay between host and virus factors, including RSV load.
authors.affiliation: Research Unit UR06SP20, Laboratory of Bacteriology-Virology, University Hospital Sahloul, Sousse, Tunisia.
authors.forename: Imène
authors.initials: I
authors.lastname: Fodha
authors.forename: Astrid
authors.initials: A
authors.lastname: Vabret
authors.forename: Leila
authors.initials: L
authors.lastname: Ghedira
authors.forename: Hassen
authors.initials: H
authors.lastname: Seboui
authors.forename: Slaheddine
authors.initials: S
authors.lastname: Chouchane
authors.forename: John
authors.initials: J
authors.lastname: Dewar
authors.forename: Neji
authors.initials: N
authors.lastname: Gueddiche
authors.forename: Abdelhalim
authors.initials: A
authors.lastname: Trabelsi
authors.forename: Noureddine
authors.initials: N
authors.lastname: Boujaafar
authors.forename: François
authors.initials: F
authors.lastname: Freymuth
mesh_terms: D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis* / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000145:classification*; D019562:Viral Load