Influence of respiratory viruses, cold weather and air pollution in the incidence of lower respiratory tract infections in infants children

Background: All winters, there is an increase in the number of pediatric co nsultations, associated to three factors: cold weather, air pollution and r espiratory virus epidemics. Aim: To study the influence of these three fact ors in the demand for pediatric consultations between March and September, in an area of Metropolitan Santiago. Patients and Methods: The number of co nsultations between March and September 1998 in the emergency room and the number of hospital discharges due to lower respiratory tract infections, we re registered in a public pediatric hospital of Santiago. A respiratory vir us surveillance (respiratory syncytial virus, adenovirus, influenza and par ainfluenza virus) was done among children admitted for lower respiratory in fections. Atmosphere temperature values and air pollution, measured as the number of particles of 10 mu m or more per m(3) (MP 10), were obtained from local health services. Results: Two elevation waves of outpatient consulta tions were detected at weeks 19 and 26, that coincided with the periods of maximal detection of influenza and syncytial respiratory virus, respectivel y. The epidemics of respiratory syncytial virus coincided with the maximal number of hospital admissions for lower respiratory tract infections at wee k 27. There was no correlation between air pollution and the number of pedi atric consultations. The lower ambient temperatures coincided with the high er detection of respiratory syncytial virus at week 28, moment in which the demand for consultations or hospital admissions was descending. Conclusion s: There is a direct relationship between respiratory virus epidemics and t he demand for pediatric consultations. There is also a minor influence of a mbient temperature.