南宁市2019年登革热暴发疫情与当年伊蚊监测数据分析

An analysis of dengue fever outbreak and Aedes surveillance data in Nanning,Guangxi Autonomous Region,China,2019

目的分析广西壮族自治区南宁市2019年登革热暴发疫情与伊蚊监测密度的相关性,评价南宁市媒介伊蚊监测数据对登革热暴发流行预警的作用,为改进伊蚊监测工作提供参考。方法收集南宁市2019年登革热暴发疫情病例资料和当年的伊蚊监测资料,采用描述性流行病学方法,分析疫情暴发的流行病学特点和伊蚊密度消长的情况及二者相关性。结果2019年首例本地病例发病日期是6月28日,发病时间四分位数Q25、Q50、Q75分别是9月29日、10月9日和10月20日,6-12月的月病例数分别是1、0、12、275、647、93、5例;常规监测全市的布雷图指数(BI)在6、7和9月处于全年的较高水平,但全市和病例数较多的江南、西乡塘、青秀和良庆区的BI均<5;常规监测全市的诱蚊诱卵指数(MOI)在6、8和9月处于全年的较高水平,但全市和青秀区MOI均<5;常规监测全市的帐诱指数在5、6、7和9月均>2只(/顶·h),但西乡塘和良庆区帐诱指数均<2只(/顶∙h);应急监测(灭蚊前)全市BI几乎都>5;应急监测(灭蚊前)良庆区帐诱指数<1只(/顶∙h);应急监测(灭蚊后)青秀和良庆区的BI比常规监测高。各月登革热病例数与常规监测、应急监测和总BI、MOI(应急监测无此指标)和帐诱指数未显示出统计学意义的相关性(均P>0.05)。结论南宁市2019年的伊蚊监测数据总体上未显示出与当年登革热暴发疫情的相关性,具体原因有待进一步调查分析,南宁市媒介伊蚊监测工作和数据利用需进一步完善。

Objective To analyze the correlation between the dengue fever outbreak and Aedes surveillance density in Nanning,Guangxi Autonomous Region,China in 2019,and evaluate the role of Aedes surveillance in the early warning of dengue outbreaks in Nanning,and to provide a reference for improving local surveillance of Aedes mosquitoes.Methods We collected the data on the dengue outbreak and Aedes surveillance in Nanning in 2019 to analyze the epidemiological characteristics of the outbreak,the fluctuations in the density of Aedes mosquitoes,and the correlation between the outbreak and Aedes density fluctuations using descriptive epidemiological methods.Results The date of onset of the first local case of dengue fever in 2019 was June 28,and the quartiles(Q25,Q50,and Q75)of onset time were September 29,October 9,and October 20,respectively.The monthly cases of dengue fever from June to December were 1,0,12,275,647,93,and 5,respectively.The Breteau index(BI)by routine surveillance in Nanning was higher in June,July,and September in 2019,but in Nanning and its Jiangnan district,Xixiangtang district,Qingxiu district,and Liangqing district with the largest numbers of cases,the BI was all<5.The mosquito ovitrap index(MOI)by routine surveillance in Nanning was higher in June,August,and September in 2019,but the MOI in Nanning and its Qingxiu district was both<5.The mean net trap index by routine surveillance in Nanning was>2 mosquitoes/net·hour in May,June,July,and September,but it was<2 mosquitoes/net·hour in Xixiangtang district and Liangqing district.Before mosquito control,the BI by emergency monitoring was almost all>5 across Nanning,and the net trap index by emergency monitoring was<1 mosquito/net·hour in Liangqing district.After mosquito control,the BI of Qingxiu and Liangqing districts by emergency monitoring was higher than that by routine monitoring.The number of cases of dengue fever in each month had no significant correlation with the BI,MOI,or net trap index,regardless of routine surveillance,emergency surveillance,and overall analysis(all P>0.05).Conclusion The surveillance densities of Aedes mosquitoes in Nanning in 2019 were generally not correlated with the dengue fever outbreak in that year.The specific reasons need further investigation,and Aedes surveillance and data utilization in Nanning need to be improved.