1999—2015年红塔区伤寒与副伤寒流行特征和气象变量的研究

Epidemiological features of typhoid/paratyphoid fever and meteorological variables from 1999 to 2015 in Hongta area,China

目的分析1999-2015年红塔区伤寒与副伤寒(typhoid and paratyphoid fever,TPF)地方病区域流行特征和气象变量的关系,为TPF监测控制和危险因素评价提供科学依据。方法采用描述流行病学方法和自主研发计算机软件建立中国疾病预防控制信息系统红塔区TPF病例分布与流行特征数据库,用Pearson相关分析和多元线性逐步回归分析研究TPF发病和气象变量关系。结果 1999-2015年报告TPF病例数为8 398例,1999、2015年分别报告23、44例。1999-2015年期间每年3~5月、6~10月、11月~次年2月分别为发病上升期(月均增长率63.8%)、高峰期(月均降低率2.0%)和下降期(月均降低率25.7%),每年度病例数都呈现3月~10月季节性升高和11月~次年2月季节性降低;2000年8月至2010年12月每月病例数都大于8例,2000-2002、2004-2005、2005-2007、2007-2008、2008-2010年出现五个高强度流行峰,峰期范围是12~24个月,周期范围是11~40个月;2001、2004、2006、2007、2009年五个高峰年度6~10月病例数范围分别为86~217、67~215、125~216、97~131、63~95例;1999、2000、2002、2003、2005、2008、2010、2015年八个低峰年度6~10月病例数范围分别为1~3、1~17、32~60、30~43、46~55、43~78、22~61、2~11例。单因素分析TPF月平均发病率与月平均降雨量(r=0.825,P<0.01)、月平均气温(r=0.797,P<0.01)和月平均相对湿度(r=0.706,P<0.05)呈正相关;经多元逐步回归分析建立TPF月平均发病率(Y)与月平均降雨量(X)的拟合模型方程Y=4.563+0.051X。结论红塔区TPF发病呈现季节性升高与降低、周期性流行、长期趋势特点;发病率与降雨量、气温、相对湿度呈正相关;传染源积累、重污染源形成、暴露人群增加驱动着流行特征与气象变量关系;相应规律、机制、政策、评估有助TPF的监测控制。

Objective To analyze the associations between the epidemiological features of typhoid/paratyphoid fever （TPF） and meteorological variables in Hongta area from 1999 to 2015, and provide scientific basis for TPF monitoring and control, as well as risk factor evaluation. Methods Descriptive epidemiology method and independently-developed computer software were used to establish the database of distribution and epi demlc features of TPF cases in Hongta District. The impacts of rainfall, temperature and relative humidity on incidence of TPF were analyzed with Pearsonls correlation analysis and multiple stepwise regression anal ysis. Results 8,398 cases of TPF were reported from 1999 to 2015, including 23 and 44 cases in 1999 and 2015 respectively. The annual growth period, peak period and decline period of TPF cases were during March-May （average monthly growth rate of 63.8%）, June-October （average monthly reduction rate of 2.0%）, and November-February （average monthly reduction rate of 25.7%）, respectively. The annual number of cases showed a seasonal increase from March to October, and a seasonal decline from November to February. Five high-intensity epidemic peaks appeared during 2000 - 2002, 2004 - 2005, 2005 - 2007, 2007 - 2008 and 2008 - 2010 respectively; the peak periods ranged from 12 to 24 months, and the cyclic fluctuation periods ranged from 11 to 40 months. Pearsonrs correlation analysis showed that the monthly average incidence of TPF was positively correlated with the monthly average rainfall （r= 0. 825, P〈0.01）, monthly average temperature （r=0. 797, P〈0.01） and monthly average relative humidity （r=0. 706, P〈 0.05） . The fitted model equation of monthly average incidence （Y） and monthly average rainfall （X） of TPF was Y=4. 563＋0. 051X, established by multiple stepwise regression analysis. Conclusion The incidence of TPF in Hongta area featured seasonal increase/reduction, periodic prevalence and long term trend; the incidence of TPF is closely related to rainfall, temperature and relative humidity. The accumulation of infectious sources, the formation of heavy pollution sources and the increase of exposed population contribute to the relationships between the epidemiological features of TPF and meteorological variables.