河南省流行性乙型脑炎流行特征与防控策略探讨

目的 分析河南省流行性乙型脑炎(乙脑)流行趋势、特征,以及影响因素和防控策略.方法 对1980-2008年河南省64 401例乙脑患者资料用Excel 2003和SPSS 12.0软件进行统计、分析.并选取罗山、新安、西华、邓县、滑县为监测点,5-10月每旬1次,用人工小时法和蚊帐法采集蚊虫标本,计算蚊虫密度.同时每旬采集30～40头仔猪血液标本,用酶联接免疫吸附剂测定(EHSA)方法检测猪血清乙脑IgG抗体.结果 1980-2008年河南省乙脑累计发病64 401例,发病率波动在0.34/10万(315/93 599 969)～6.72/10万(5246/78 076 567),其中1980-1994年平均发病率为4.39/10万(3530/80 381 469),1995-2008年平均发病率为0.86/10万(811/94 217 549),2008年达最低,为0.34/10万(315/93 599 969);发病集中于7-9月,占89.40%(57 572/64 401);患者主要分布在信阳、南阳、驻马店、周口、洛阳五市,占81.02%(52 175/64 401);河南省发病年龄以0～14岁为主(79.01%,50 884/64 401),洛阳市≥15岁明显上升(57.83%,2120/3666),二者发病年龄构成比经χ~2检验差异有统计学意义(χ~2=2705.32,P<0.05);监测点蚊虫密度高低的不同、猪乙脑抗体50%阳转日早晚的差异,反映了乙脑发病的强度.结论 河南省乙脑发病呈下降性、季节性、地域性和年龄分布差异的特点,监测宿主动物猪乙脑抗体水平和媒介蚊虫密度可以预测乙脑流行趋势.控制全省小年龄组、洛阳市大年龄组和高发区人群的发病,加强监测和预测,是河南省乙脑防控的重点.

The prevalence characteristic and prevention strategy of Japanese B Encephalitis in Henan province

Objective To analyze the prevalence trend, prevalence characteristics and influence factors of Japanese B Encephalitis (JE) in Henan province. Methods The data that of 64 401 JE patients in Henan from 1980 to 2008 were statistically analyzed by SPSS12. 0 and EXCEL2003 software. Luoshan, Xinan,Xihua, Deng county and Hua county were chosen as monitoring sites. The mosquito specimens were gathered with the artificial hour method and the mosquito curtain method ,the mosquito density was calculated one time each ten day period from May to July. At the same time, 30 -40 newborn pig blood samples were gathered each ten-day period and the pig serum JE IgG antibody was detected by ELISA method. Results The Cumulative incidence of JE was 64 401 cases in Henan province from 1998 to 2008, the range of incidence rate was from 0. 34/100 000 (315/93 599 969 ) to 6. 72/100 000 (5246/78 076 567) ; The average incidence of JE was 4. 39/100 000 (3530/80 381 469) from 1980 to 1994;The average incidence of JE was 0. 86/100 000 (811/94 217 549) from 1995 to 2008;In 2008,the incidence rate reached the lowest point for 0.34/100 000(315/93 599 969) ; The incidence occurred mainly in July-September,accounting for 89. 40% of the total eases (57 572/64 401 );the patients were concentrated mainly in 5 cities, which were Xinyang, Nanyang,Zhumadian, Zhoukou, Luoyang, accounting for 81.02% (52 175/64 401 ). The 0 - 14 years old age group was the dominant group (79.01% ,50 884/64 401). In Luoyang city,incidence of≥15 years old group was significantly increased (57. 83%, 2120/3666 ), the constitution of JE incidence were significantly different between 0 - 14 years old group and ≥15 years old age group (χ~2=2705. 32,P< 0.05) in Henan province and Luoyarlg city. The different density of the mosquitoes and the different positive -times for 50% of the antibodies of JE in piglets on the monitor sites showed the intensity of JE disease. Conclusion The incidence of JE showed a decreasing trend, seasonal, regional characteristics and age distribution difference in Henan province. The monitoring of host animal pig JE antibody level and the medium mosquito density may forecast the JE prevalence tendency. To control the incidence in the younger groups in Henan province, older age group in Luoyang city and high-incidence areas, it is important to strengthen the monitoring and forecasting measures to prevent JE in Henan province.