Climatic factors and lower respiratory tract infection due to respiratory syncytial virus in hospitalised infants in northern Spain.

Objective: To analyse the influence of climatic factors on the number of hospitalised infants with respiratory syncytial virus (RSV) per week.

Methods: A retrospective observational case-control study was designed enrolling infants under 2 years of age, admitted to hospital between October 1995 and June 2000 with lower respiratory tract infection due to RSV. Climatic and seasonal data were included.