title: Predictors of hospitalization for lower respiratory tract infection in children aged <2 years in the province of Quebec, Canada.
abstract: Young age, adverse environmental conditions and infectious agents are established risk factors of lower respiratory tract infection (LRTI), whereas pneumococcal conjugate vaccines may be protective. To explore their relative role as predictors of hospitalizations under the continental climate prevailing in the province of Quebec, Canada, an ecological study was performed. Records with a main diagnosis of LRTI in children born during 2007-2010 and observed up to their second-year anniversary were extracted from the provincial hospital administrative database. Respiratory virus surveillance data and statistics on ambient air temperature were obtained. Vaccine use in different birth cohorts was derived from the Quebec City Immunization Registry. Additive and multiplicative Poisson regression models were applied to estimate attributable fractions. Age, month of birth, ambient temperature, and respiratory syncytial virus (RSV), human metapneumovirus (hMPV) and influenza-positive test proportions were significant predictors of LRTI hospitalizations. No substantial differences were observed in cohorts exposed to the 7-valent or 10-valent pneumococcal conjugate vaccines. In the additive model, the fraction of hospitalizations explained by temperature variation was 37%, whereas RSV circulation explained 28%, hMPV 4% and influenza 1%. Complex interplay between biological, environmental and social mechanisms may explain the important role of ambient air temperature in predicting LRTI hospitalization risk in young children.
authors.affiliation: Quebec University Hospital Research Center,Quebec City,Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Direction des Risques biologiques et Santé au Travail,Institut national de Santé publique du Québec,Quebec City,Canada.
authors.forename: R
authors.initials: R
authors.lastname: Gilca
authors.affiliation: Quebec University Hospital Research Center,Quebec City,Canada.
authors.forename: G
authors.initials: G
authors.lastname: Deceuninck
authors.affiliation: Departement of Pediatrics,Laval University,Quebec City,Canada.
authors.forename: F D
authors.initials: FD
authors.lastname: Boucher
authors.affiliation: Laboratoire de Santé publique du Québec,Institut national de Santé publique du Québec,Sainte-Anne-de-Bellevue,Canada.
authors.forename: H
authors.initials: H
authors.lastname: Charest
authors.affiliation: Departement of Social and Preventive Medicine,Laval University,Quebec City,Canada.
authors.forename: P
authors.initials: P
authors.lastname: DE Wals
mesh_terms: D000367:Age Factors; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011792:Quebec / Q000453:epidemiology; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology*; D012307:Risk Factors; D013696:Temperature
chemical_list: D022242:Pneumococcal Vaccines
keywords: Ambient temperature; ecological study; hospital admissions; pneumococcal conjugate vaccine; respiratory infections; respiratory virus