Down syndrome increases risk of hospitalization for RSV

Abstract

Zachariah et al in Colorado used three retrospective administrative databases and study designs to investigate hospitalizations of children with Down syndrome (DS) due to respiratory synctial virus lower respiratory tract infection (RSV LRTI) during the approximate years of 1995 to 2006. They were able to show that population-based incidence of RSV LRTI in DS was approximately 6-fold higher than in children without DS (67 versus 12 per 1000 child-years during the first 2 years of life, respectively). Children with DS without other underlying conditions (such as congenital heart disease, pulmonary hypertension, chronic lung disease or prematurity) still had higher incidence of RSV LRTI hospitalization (42 per 1000 child-years; OR 3.5, 95% CI 3.10-4.12) than children without DS. Severity scores, clinical features of fever, pulmonary consolidation, bronchodilator use, and durations of hospitalization also were higher in patients with DS.Interpretation of these conglomerated studies has substantial limitations, such as use of administrative databases alone to capture infants with DS in Colorado, assumption of accurate and complete coding of underlying conditions and clinical findings, lack of knowledge of co-factors such as number of siblings and daycare attendance, and potential biases of providers to over-admit and over-treat patients with DS.Despite limitations, the conclusion that children with DS (at least in Colorado) with and without underlying conditions have increased severity of RSV LRTI is likely to be valid. This fits with accumulating evidence of innate and adaptive immunologic differences in these patients, as well as potential vulnerability because of altered anatomy and function of the upper and lower respiratory tract. Prospective, generalizable, rigorous data on incidence of hospitalization of patients with DS with RSV LRTI, as well as a fuller understanding of complex reasons for hospitalization, and efficacy and safety of monoclonal antibody prophylaxis in this population are lacking. The findings of this study should not be construed as evidence to indicate palivizumab use for all children with DS. This study does highlight room for improvement in implementation of current recommendations for palivizumab prophylaxis. Of the 35 children with DS admitted with RSV LRTI to The Children's Hospital Denver from 2000-2006, 19 children had underlying conditions that likely indicated its use, but only 1 child had received antibody prophylaxis.Article page 827▶ Zachariah et al in Colorado used three retrospective administrative databases and study designs to investigate hospitalizations of children with Down syndrome (DS) due to respiratory synctial virus lower respiratory tract infection (RSV LRTI) during the approximate years of 1995 to 2006. They were able to show that population-based incidence of RSV LRTI in DS was approximately 6-fold higher than in children without DS (67 versus 12 per 1000 child-years during the first 2 years of life, respectively). Children with DS without other underlying conditions (such as congenital heart disease, pulmonary hypertension, chronic lung disease or prematurity) still had higher incidence of RSV LRTI hospitalization (42 per 1000 child-years; OR 3.5, 95% CI 3.10-4.12) than children without DS. Severity scores, clinical features of fever, pulmonary consolidation, bronchodilator use, and durations of hospitalization also were higher in patients with DS. Interpretation of these conglomerated studies has substantial limitations, such as use of administrative databases alone to capture infants with DS in Colorado, assumption of accurate and complete coding of underlying conditions and clinical findings, lack of knowledge of co-factors such as number of siblings and daycare attendance, and potential biases of providers to over-admit and over-treat patients with DS. Despite limitations, the conclusion that children with DS (at least in Colorado) with and without underlying conditions have increased severity of RSV LRTI is likely to be valid. This fits with accumulating evidence of innate and adaptive immunologic differences in these patients, as well as potential vulnerability because of altered anatomy and function of the upper and lower respiratory tract. Prospective, generalizable, rigorous data on incidence of hospitalization of patients with DS with RSV LRTI, as well as a fuller understanding of complex reasons for hospitalization, and efficacy and safety of monoclonal antibody prophylaxis in this population are lacking. The findings of this study should not be construed as evidence to indicate palivizumab use for all children with DS. This study does highlight room for improvement in implementation of current recommendations for palivizumab prophylaxis. Of the 35 children with DS admitted with RSV LRTI to The Children's Hospital Denver from 2000-2006, 19 children had underlying conditions that likely indicated its use, but only 1 child had received antibody prophylaxis. Article page 827▶