ABSTRACT
Objective TostudytheinfluenceofmeteorologicalconditionschangingontheactivityintensityofinfluenzaA (H1 N1 )and to establish the prediction model of H1 N1 positive rate associated with meteorological factors.Methods TheinfluenzaA(H1N1)datafromAprilof2009toJanuaryof2011insentinelhospitalanddailymeteorologicaldatain the same period were collected,which were analyzed by Spearman correlation analysis.The prediction model was establishedusingChi-squaredautomaticinteractiondetector(CHAID).Results Weeklyaverageatmospheric pressure(r =0.50),highest atmospheric pressure (r =0.51 ),lowest atmospheric pressure (r =0.50),average temperature (r=-0.40),highest atmospheric temperature(r=-0.41),lowest atmospheric temperature(r=-0.39), precipitation(r=-0.23 )and average wind speed (r=-0.22 )were positively correlated with the activity intensity of H1N1(all P<0.05).Factors that affected H1N1 positive rate were lowest atmospheric pressure,average wind speed and precipitation(P<0.05 ).The prediction model of H1 N1 positive rate showed that the correct rate of prediction was 66.67%.Conclusion Lowestatmosphericpressure,averagewindspeedandprecipitationarecloselyassociatedwith the activity intensity of influenza A (H1 N1 ).CHAID method can be used to predict the H1 N1 epidemics.
ABSTRACT
Objective To discuss the relationship between chronic bronchitis and meteorological conditions in Nanjing. Methods Took the record of the recrudescing time of 200 old chronic bronchitis patients for a year. The correlation between the changing of air temperature and pressure and the monthly chronic bronchitis recrudescing in a year was analyzed. The main meteorological conditions by which recrudescing were affected in different season were selected with multiple stepwise correlation analysis. Results There were chronic bronchitis patients recrudescing the whole year, but the most were in winter and the least in summer. The most recrudescing happened in December and April, and the least in May and July. The meteorological factors that affected chronic bronchitis patients recrudescing were air temperature, pressure and wind speed. The relative coefficient of case numbers between 24 hours variations of air temperature and pressure was 0.5762(P=0.0499) and 0.5841(P=0.0461), respectively. Conclusion The steady meteorological conditions are not good for recrudescing of chronic bronchitis patients. And temperature descent and high air pressure are the main meteorological factors that induce chronic bronchitis recrudescing.