基于增强回归树模型评估宁夏回族自治区气象因素和大气污染物对流行性腮腺炎发病影响

Associations of meteorological factors and ambient air pollutants with mumps incidence in Ningxia Hui Autonomous Region:boosted regression tree model analysis

目的评估宁夏回族自治区气象因素和大气污染物对流行性腮腺炎发病的影响,为流行性腮腺炎的早期预防和反应系统的建设提供参考依据。方法收集宁夏回族自治区2015年1月1日—2019年12月31日流行性腮腺炎的发病数据以及每日气象和大气污染物数据,应用增强回归树(BRT)模型来确定最能解释流行性腮腺炎新发病例的气象因素和大气污染物的最佳滞后,并评估该地区气象因素和大气污染物对流行性腮腺炎发病的影响。结果宁夏回族自治区2015—2019年流行性腮腺炎新发病例数为6660例,其中男性3936例(59.1%),女性2724例(40.9%);年龄<4岁2230例(33.5%),4~15岁3537例(53.1%),>15岁893例(13.4%)。BRT模型验证结果显示,滞后7 d时模型具有最大的训练集受试者工作特征曲线下面积(AUC)值为0.915、测试集AUC值为0.717、标准误为0.027,宁夏回族自治区1周前气象因素和大气污染物对流行性腮腺炎新发病例变化的解释作用最大。BRT模型分析结果显示,日均气温对流行性腮腺炎发病的相对重要性最大为26.36%,其次为日均相对湿度,相对重要性为13.90%;日均气温–3℃~23℃和日均相对湿度>40%为流行性腮腺炎发病风险增加的原因;较高的日均气压和日均风速对流行性腮腺炎的发病具有抑制作用;空气中臭氧(O_(3))浓度较低时对流行性腮腺炎的发病具有促进作用;空气中二氧化硫(SO_(2))浓度<100μg/m^(3)时对流行性腮腺炎的发病具有促进作用,浓度≥100μg/m^(3)则转变为抑制作用;较低浓度的一氧化碳(CO)、二氧化氮(NO_(2))、细颗粒物(PM_(2.5))和可吸入颗粒物(PM_(10))均对流行性腮腺炎的发病具有促进作用。结论宁夏回族自治区日均气温、日均相对湿度、日均气压、日均风速等气象因素以及O_(3)、SO_(2)、CO、NO_(2)、PM_(2.5)、PM_(10)等大气污染物在一定范围内对流行性腮腺炎的发病均具有显著促进作用。

Objective To evaluate the associations of meteorological factors and ambient air pollutants with the incidence of mumps in Ningxia Hui Autonomous Region,and to provide a reference for the development of early warning and response systems for mumps epidemic.Methods Data on the daily number of mumps cases in Ningxia Hui Autonomous Region from 2015 to 2019 were obtained from the Notifiable Infectious Disease Surveillance System of the region,and data on meteorological factors(daily mean temperature/relative humidity/atmospheric pressure/wind speed)and air pollutants(daily concentrations of ozone,[O_(3)],sulfur dioxide[SO_(2)],carbon monoxide[CO],nitrogen dioxide[NO_(2)],and particulate matter with aerodynamic diameter<2.5/10 mum[PM_(2.5)/PM_(10)])for the same period were obtained from the National Meteorological Science Data Center.A boosted regression tree(BRT)model was used to determine the optimal lag of meteorological factors and air pollutants that best explained mumps cases and to evaluate the associations of meteorological factors and air pollutants with the daily number of mumps cases in the region.Results A total of 6660 new cases of mumps were reported in the region during the period,including 3936 males(59.1%)and 2724 females(40.9%);2230(33.5%)were aged less than 4 years,3537(53.1%)were aged 4–15 years and 893(13.4%)were aged>15 years.The BRT model validation results showed that the model had the largest area under the receiver operating characteristic curve(AUC)value of 0.915 for the training set and 0.717 for the test set at a lag of 7 days,with a standard error of 0.027,indicating that in the region,meteorological factors and air pollutants one week prior had the greatest explanatory power for changes in the number of new mumps cases.BRT model analysis showed that daily mean temperature had the greatest relative importance on mumps incidence at 26.36%,followed by daily mean relative humidity at 13.90%.Daily mean temperatures of–3℃to 23℃and daily mean relative humidity>40%were risk factors for mumps incidence.Higher daily mean barometric pressure and daily mean wind speed had an inhibitory effect on mumps incidence.Lower ambient O_(3)concentrations promoted mumps incidence;ambient SO_(2)concentrations<100μg/m^(3)promoted mumps incidence,whereas SO_(2)concentrations≥100μg/m^(3)had an inhibitory effect.Lower concentrations of CO,NO_(2),PM_(2.5),and PM_(10)all promoted mumps incidence.Conclusion Daily mean temperature/relative humidity/air pressure/wind speed,as well as ambient air O_(3),SO_(2),CO,NO_(2),PM_(2.5),and PM_(10),all significantly contributed to the incidence of mumps in Ningxia Hui Autonomous Region.