Analysis On The Relationship Between Influenza And Meteorology In Hangzhou And The Establishment Of Early Warning Models

ObjectiveInfluenza is an acute respiratory infectious disease which could be a severe threat to all human beings. It can cause an outbreak or epidemic among people, or even a worldwide pandemic, thus leading to increased morbidity and mortality eventually. Therefore, surveillance and early warning of this disease have been the routine tasks in many countries. This study aims to assess the effects of diverse meteorological indicators on the number of influenza-like illness in Hangzhou, and establish suitable early warning models of them, in order to provide guidance to practice as well as minimize the social and economic losses.MethodsBased on the daily number of influenza-like illness collected from certain hospitals and meteorological data in Hangzhou during2007to2009, the delayed and cumulative effects of different meteorological indicators on influenza-like illness were examined using generalized additive models and distributed lag non-linear models. The maximal lag was set to7days.ResultsIt was found that the daily average temperature of34.8degrees Celsius, the temperature range of0.6degrees Celsius, the atmospheric pressure of1010.0hectopascal, the relative humidity of64%and the wind velocity of0.6meters per second were the values of minimal overall relative risk of influenza-like illness, while the temperature of7.0degrees Celsius, the temperature range of17.6degrees Celsius, the atmospheric pressure of1033.4hectopascal, the relative humidity of24%and the wind velocity of6.4meters per second were the situations of maximal overall relative risk over a lag of7days. The relative risks of morbidity vary according to different meteorological indicators and lags.ConclusionsAll of daily meteorological indicators concerned in the study may have effects on the number of influenza-like illness. Particularly, the lower temperature below16.0degrees Celsius, the larger temperature range above13.0degrees Celsius, the higher atmospheric pressure above1020.0hectopascal, the faster wind velocity above4.0meters per second and either lower relative humidity below40%or higher one above70%indicate an increased risk of influenza-like illness.