目的:对河南省报告的新型冠状病毒肺炎确诊病例流行病学特征与临床特征进行描述与分析.方法:选取截至2020年2月19日中国疾病预防控制信息系统报告的河南省所有新型冠状病毒肺炎确诊病例,结合传染病报告卡和个案调查,分析其流行病学特征和临床特征.结果:1237例确诊病例中,男性680例(55.0％),女性557例(45.0％);中位年龄45岁;城市559例(45.2％),农村678例(54.8％).发病高峰在2020年1月24日,报告病例较多的省辖市为信阳、郑州、南阳、驻马店和商丘.临床症状主要有发热(87.4％)、干咳(37.2％)、乏力(25.1％)、咳痰(25.1％),发病早期白细胞正常或减少(95.8％)、淋巴细胞减少(36.2％),胸部CT影像结果异常(95.7％).重症病例年龄中位数(53岁)大于轻症病例(44岁),差异有统计学意义(P<0.001).重症病例慢性基础性疾病、最高体温>38℃、干咳、呼吸困难、淋巴细胞减少、胸部X射线影像结果异常、胸部CT影像结果异常、收入ICU治疗的比例均高于轻症病例,差异有统计学意义(P<0.05).重症病例发病到报告、发病到隔离、发病到确诊时间间隔均大于轻症病例(P<0.05).结论:河南省新型冠状病毒肺炎病例主要发生在男性、农村、20～59岁人群,主要分布在与湖北接壤的豫南地区和郑州市.应关注重点地区、重点人群,针对重症的危险因素早期进行预警,积极救治,改善预后.

目的 分析发热伴血小板减少综合征(FTLS)季节性特征.方法 FTLS疫情资料来源于国家疾病监测信息报告管理系统,应用集中度、季节指数和圆形分布法分析FTLS季节性分布特征.结果 2009-2014年,信阳市共报告FTLS病例2901例,发病呈逐年上升趋势(Z=23.822,P＜0.001).2009-2014年各年度FTLS集中度M值分别为0.564、0.557、0.636、0.645、0.561和0.566,平均值为0.585.不同月份和季度的季节指数均不相同.5月份季节指数最大,为292.04％;2月份季节指数最小,为0.41％.第1-4季度各季度季节指数分别为5.24％、213.03％、142.71％和39.02％.2009-2014年信阳市各年份FTLS发病均存在集中趋势(雷氏检验P值均＜0.05),6年间信阳市FTLS流行高峰期为4月27日-8月25日.应用Watson-Williams检验对不同年份的平均角(a)进行检验,F=7.036,P＜0.05,不同年份FTLS发病高峰日不完全相同.实际流行高峰期与圆形分布拟合的流行高峰期开始时间基本一致,从4月下旬或5月上旬开始,但持续时间延长,最长持续至10月上旬.结论 信阳市FTLS发病具有明显的季节性,发病高峰出现在第2季度,可用圆形分布法来粗略估计其流行高峰期.

目的 探讨新布尼亚病毒感染致发热伴血小板减少综合征发病的危险因素.方法 采用1∶2配对的病例-对照研究,对40例病例和80例对照进行问卷调查,同时采集患者血清标本,应用荧光RT-PCR和IgM、IgG抗体试剂盒检测新布尼亚病毒核酸及抗体.采用条件Logistic回归分析发病的危险因素.结果 病例组农民占90.00％(36/40),显著高于对照组62.50％(50/80)(P＜0.01).病例组暴露于养狗、养猫、养牛、家禽养殖、生活区周围有蜱、病前1月被蜱叮咬、从事田间作业、工作区及住宅周围有杂草灌木的风险显著高于对照组(OR值均大于1,P值均小于0.05).多因素分析表明,在调整了性别、年龄、民族和职业因素后,生活区周围有蜱(OR=5.44,P＜0.01)是新布尼亚病毒感染致发热伴血小板减少综合征发病的危险因素.结论 不同形式的蜱暴露为新布尼亚病毒感染致发热伴血小板减少综合征的危险因素.

Objective To understand the species, distribution and genotype of mosquito?borne arboviruses in some regions of Henan province. Methods Mosquito samples were collected from Xixian county and Xin’an county in Henan province from May to August, 2012. After species identification, mosquitoes were inter?cells cross cultured for viral isolation. RT?PCR using specific primer for common arboviruses was used to identify the positive isolates. Molecular biological analysis were conducted by using software of Clustal X2.1, MegAlign, Genedoc 3.2 and Mega v5.1, and genotype for the virus was identified. Results A total of 7149 mosquitoes which belong to 5 species in 4 genera were collected. The predominant mosquito specie in Xin’an county was Armigeres subalbatus (2055, 51.36%), but the mainly species in Xixian county was Culex pipens pallens (2964, 94.16%). Five strains from Cx. pipens pallens and Cx. tritaeniorhynchus were identified as genotypeⅠJapanese encephalitis virus (JEV), which caused slightly cytopathic effect (CPE) in C6/36 cells, and no CPE in BHK-21. But severe CPE was observed in BHK-21 when 3 days after inoculating the C6/36 culture of the viruses onto BHK-21 cells. Conclusion In Xixian county and Xin’an county of Henan province, both JEV and its primary vectors exist, and GenotypeⅠJEV is still the mainly JEV circulating in local natural environment.

目的 探讨发热伴血小板减少综合征(SFTS)死亡病例的流行病学和临床特征.方法 应用病例-对照研究方法,分别对16例SFTS死亡病例(病例组)和16例一般病例(对照组)的临床与流行病学信息进行统计分析,本研究所有病例均为发热伴血小板减少综合征实验室确诊病例.结果 病例组和对照组有蜱叮咬史的比例分别为25.00％和18.75％,有田间劳作史的比例分别为75.00％和81.25％,差异均无统计学意义(P值均＞0.05).死亡病例发病至死亡平均时间为10天,发病至确诊平均时间为4天.病例组从发病到首诊的时间间隔和住院治疗天数均显著小于对照组,差异有统计学意义(P值均＜0.05).62.50％的死亡病例伴有基础疾病,显著高于对照组25％的比例,差异有统计学意义(P=0.035).病例组具有神经系统症状的比例(87.50％)显著高于对照组(37.50％),差异有统计学意义(P＜0.05).病例组ALT、AST、LDH、CK和BUN均高于对照组,但两组比较差异均无统计学意义.结论 既往有基础疾病史和有神经系统症状的患者,死亡风险较高.

目的 分析2012～2013年河南省发热伴血小板减少综合征(SFTS)流行特征及病原学特点. 方法 应用描述流行病学方法分析河南省2012～2013年SFTS病例特征,利用PHGIS1.7.0软件绘制SFTS地区分布图,采用时间分布曲线结合圆形分布法分析SFTS季节性分布特征.收集病例急性期血清标本,应用实时荧光定量RT-PCR检测发热伴血小板减少综合征布尼亚病毒(SFTSV)核酸. 结果 2012～2013年河南省共报告SFTS病例1 225例,确诊病例年均发病率为0.2948/10万.死亡18例,病死率为1.47％.信阳市报告病例1 210例,占98.78％.病例主要集中在4～10月,5月份出现第1个发病高峰,9月份出现第2个发病高峰;2年间SFTS总的流行高峰期为4月23日～8月18日,SFTS发病在时间上存在集中趋势(Z=nr2=441.00,P＜0.01).男性发病率0.4869/10万,女性发病率为0.8292/10万,差异有统计学意义(x2 =84.35,P＜0.01).病例年龄1～93岁,平均59岁,其中40～79岁年龄组占病例总数的90.29％.农民1 172例,占病例总数的95.67％.本省医疗机构共报告SFTS 1 207例,占病例总数的98.53％;三级医院、二级医院和一级医院分别占报告机构总数的60.87％、30.43％和8.70％.2012和2013年SFTSV检测阳性率为57.14 ％和50.87％,差异无统计学意义(x2=3.21,P＞0.05). 结论 河南省SFTS发病具有明显的地域性和季节性,发病范围有扩大趋势.高龄女性农民为高危人群,SFTSV仍为主要致病病原.

In 2011, human coxsackievirus B5 (CVB5) caused an outbreak of viral encephalitis in Henan, China. Complete genome sequence analysis based on two isolates showed that the 5′ half of the genome (nt 1-4540) had high similarity (>97 %) to that of CVB5 strain GU376747, and the 3′ half (nt 4700–7402) showed high similarity (>96 %) to that of human coxsackievirus B3 (CVB3) strain GQ141875. These isolates had the highest similarity (97.7 %) to the Changchun strain, based on the complete genome, rather than to other CVB5 strains isolated from Henan in recent years. There were therefore at least two groups of CVB5 circulating in Henan Province, which evolved at different rates.

Objective To understand the risk factors for adult Japanese encephalitis (JE) in Zibo prefecture in Shandong province and Luoyang prefecture in Henan province.Methods To select the laboratory-confirmed JE cases in year 2009 and 2010 as the cases,matched by ages for the non-JE cases in the same hospital with a ratio of 1:3.To conduct investigation for both cases and controls,collecting the demographic information,occupation,economic status,health status,activities,living environment and other factors.The Chi-square test and multivariate conditional Logistic regression analysis were used for unvariate and multivariate analysis.Results Univariate analysis showed that the "Occupation was peasant"etc.totally 7 items were risk factors,and "Living in the city"etc.totally 7 items were protective factors.Multivariate analysis showed that"Feeding pigs in house or neighborhood"was the highest JE risk factor,and the estimated attributable risk percent (AR%) was 95.3 % .Conclusions Risk factors of JE for adults were similar with the previous findings conducted for children.The population of peasant,especially those feeding pigs in house or neighborhood,was targeted population need the intervention.We recommend to take comprehensive methods,including the health education,environmental improvement,JE vaccination for the high-risk population.

Objective To analyze the epidemiological characteristics of fever thrombocytopenia and leukopenia syndrome(FTLS)in Henan province,China in 2007-2011.Methods Data from specific surveillance system for FTLS in Henan and Information Management System of Chinese Center for Disease Control and Prevention were used to collect the information of the cases.Descriptive epidemiological methods were used to analyze the surveillance data during 2007-2011.Patients' sera were collected to detect new bunyavirus using fluorescent RT-PCR and virus isolation.Results During 2007-2011,1021 FTLS cases were reported in Henan province.The fatality rate was 2.25％ with 23 deaths.The cases reported in Xinyang city were 1007,accounting for 98.75％.Cases were mainly occurred between April and October,accounting for 96.47％(985/1021).Epidemic peak was May to July,accounting for 59.16％(604/1021).The second peak occurred in September,accounting for 12.05％(123/1021).The age of the cases ranged from 1 to 88 years old with the median age of 59.Sex ratio(male:female)was 1:1.50(408:613).In all cases,93.73％(957/1021)were farmers.In 465 patients' sera,the positive rate of new bunyavirus was 69.25％(322/465)using fluorescent RT-PCR.In 164 patients' sera,67 strains of new bunyavirus were isolated with isolation rate of 40.85％(67/164).Conclusion FTLS in Henan province is caused mainly by the new bunyavirus and has certain regional and seasonal characteristics.Most cases are female older farmers.

OBJECTIVE:To understand the epidemic characteristics and viral antibody level among healthy people of Japanese B encephalitis (JE) in Henan province in 2010.METHODS:A total of 433 selected JE cases in Henan province in 2010 were analyzed by descriptive epidemiological method. Xinyang and Luoyang were selected as survey sites in 2010.12 administrative villages were randomly selected from both cities. As the investigation objects, 519 healthy people from the two cities were randomly selected by eight age groups:less than one year old, 1 - 2 years old, 3 - 4 years old, 5 - 6 years old, 7 - 14 years old, 15 - 19 years old, 20 - 59 years old, and above 60 years old. A total of 1008 samples of blood specimens were collected both in May and November, and JE viral antibody was detected by micro-cytopathic effect neutralization test.RESULTS:The incidence rate of JE was 0.46/100 000 (433/94 130 434) in Henan province in 2010.97.69% (423/433) of the patients were found between July and September, and 81.06% (351/433) were distributed in Nanyang, Xinyang, Luoyang, Zhumadian and Zhoukou city. Children aged 0 to 14 years were the primarily affected group (82.22%, 356/433), the people above 15 years old accounted for 17.78% (77/433) of whole cases in Henan province, but the same group accounted for 65.79% (50/76) of whole cases in Luoyang city, which obviously higher than the percentage in Henan province (χ(2) = 79.57, P < 0.05). Most patients were scattered children in Henan province, accounting for 58.89% (255/433). In Luoyang city, most patients were peasants, accounting for 44.74% (34/76). The antibody positive rate of JE among health people above 15 years old in Luoyang city was 48.94% (46/94), which was lower than it in Xinyang city at 97.78% (88/90). The difference showed statistical significance (χ(2) = 55.42, P < 0.05). The antibody positive rate among healthy people under vaccination was 50.41% (61/121), which was obviously higher than that among people without vaccination, at 16.67% (6/36) in Luoyang city. The difference showed statistical significance (χ(2) = 12.92, P < 0.05). The antibody positive rate among healthy people under vaccination was 67.11% (51/76) in Xinyang city, which was obviously higher than that among people without vaccination, at 46.39% (45/97). The difference showed statistical significance (χ(2) = 7.40, P < 0.05).CONCLUSION:The incidence of JE showed seasonal and regional characteristics, there were differences among ages and occupations. The difference was consistent with the difference in viral antibody level among health people in Henan province and Luoyang city.

目的通过对肾综合征出血热病例县区层面空间聚集性的拟合,展示Poisson分布与负二项分布的详细计算过程。方法对河南省2010年肾综合征出血热病例县区层面分布数据按发病数进行归类整理,利用Poisson分布与负二项分布原理对其进行拟合与检验。其中负二项分布聚集性参数k采用最大似然法估算。结果 Poisson分布χ2=67.1213,P<0.05;负二项分布聚集性参数^k=0.8455,χ2=7.2543,P>0.05。结论河南省2010年肾综合征出血热病例在县区层面服从负二项分布,具有空间聚集性。

OBJECTIVE:To develop an indirect immunofluorescence assay (IFA) for detection of IgG antibodies against new bunyavirus.METHODS:The antigen slides were prepared with 5 new bunyavirus strains isolated using Africa green monkey kidney (Vero) cells. Specificity and sensitivity evaluation of IFA were carried out by optimizing working conditions of IFA. Using established IFA, serum samples from both acute and recovery phases were tested for 126 cases with fever thrombocytopenia and leukopenia syndrome in Xinyang, Henan province in 2007 - 2011. The results were compared with detections by RT-PCR.RESULTS:The new bunyavirus stable immunofluorescence specific WZ69 strain was selected to prepare antigen slides of IFA. The optimum conditions of IFA were: optimum dilution for primary antibody (serum) and secondary antibody (isosulfocyanic acid fluorescence marked goat anti-human IgG antibody) was 1:40 and 1:150 respectively. The optimum dilution for Evans blue in secondary antibody was 1:20 000. Among the 126 patients, 96 paired serum specimens were tested positive to the new bunyavirus and 30 patients were tested negative to the virus. The positive rate of antibodies was 76.19%. There was no significant difference in results between IFA and RT-PCR (72.22% (91/126)) (P > 0.05).CONCLUSION:The IFA has high sensitivity and specificity with easy operation. It can be used in detecting the new bunyavirus infection in patients with fever, thrombocytopenia and leukopenia syndrome.

Objective To identify the pathogen that caused an outbreak of viral encephalitis in Henan area in 2011.Phylogenic analysis was carried out on Coxsackie-virus B5 (CVB5) which was isolated during this outbreak.Methods Five throat swab,21 stool and 14 cerebrospinal fluid (CSF) specimens were collected from 29 inpatients during this outbreak.Viral isolation and real time RT-PCR were then performed for all specimens.Viral nucleic acid of enterovirus 71 (EV71),coxsackievirus A 16 (CA16) and pan-enterovirus (PE)were detected by real time RT-PCR.Phylogenetic tree based on entire VP1 sequences was constructed among CVB5 isolates from 2 stool and 3 CSF specimens of 5 inpatients and others published data retrieved from GenBank.Results The real time RT-PCR results showed that the PE nucleic acid positive rates of throat swab,stool and CSF specimens were 60.0％ (3/5),61.9％ (13/21) and 85.7％ (12/14) respectively.All of these specimens were negative for EV71 and CA16.The isolation rates of throat swab,stool and CSF specimens were 20.0％ (1/5),25.0％ (5/21) and 29.0％ (4/14),respectively.BLAST with both VP1 and 5′-UTR sequences and molecular typing indicated that CVB5 was the main pathogen.Analysis among the 5 positve isolates based on the complete VP1 sequences showed 97.9％-99.5％ homology.Data from homologous comparisons indicated that these isolates had the highest nucleotide acid identity with the Changchun CVB5 CC10/10/Changchun strain (97.1％-98.1％) which caused hand,foot,and mouth disease (HFMD) outbreak in Changchun in 2010,and lower identity (89.0％-89.6％ and 91.8％-92.5％) with the COXB5/Henan/2010 and 03001N strain isolated from Pingdingshan,Henan in 2010 and 2012,respectively.Phylogenetic tree in VP1 region showed that isolates of this outbreak belonged to genotype D,the same clade with Changchun strain.Conclusion CVB5 was the major etiological agent correlated with this outbreak.The shift of predominant genotype might serve as one of the causes that associated with this outbreaks.

To analyze the epidemic characteristics and influence factors of Japanese B Encephalitis(JE) in Xinyang and Luoyang of Henan Province,the epidemic situation information of JE in Xinyang and Luoyang from 2004 to 2010,the information of mosquitoes survey in 2 cities in 2010,and the information of healthy people′ antibodies in 2010 were all statistically analyzed by SPSS 12.0 and Excel 2003.JE neutralizing antibody was examining by using MCPENT.From 2004 to 2010,the annual average incidence rate of JE and the annual average mortality rate were 1.97/100,000 and 2.92% in Xinyang,and 1.01/100,000 and 9.73% in Luoyang.The 91.47% of total cases in Xinyang were occurred from July to August;84.29% of the total cases in Luoyang were occurred from August to September of 97.52% of patients in Xinyang were in 14-year-old group;57.08% of patients in Xinyang were in ≧ 15-year-old group.They had statistical significance.(χ2=557.71,P 0.05).Most patients were scattered children(68.36%) in Xinyang and farmers(46.46%) in Luoyang.The peak of mosquito density appeared from June to July in Xinyang,and the density was 25.09 per labor hour in June and 27.31 in July.The peak of mosquito density appeared from July to August in Luoyang,and the density was 13.94 per labor hour in July and 14.12 in August.The JE neutralizing antibody positive rate of ≧ 15-year-old age group was were 97.78% in Xinyang and 48.94% in Luoyang.They had statistical significance(χ2 =55.42,P0.05).The peak of incidence of JE in Xinyang was a month earlier than Luoyang and this was consistent with the peak of mosquito density.The primary patients were in 14-year-old group;in Xinyang,the primary patients were in ≧ 15-year-old group in Luoyang.This is consistent with the difference between the JE neutralizing antibody in 2 cities.Targeted prevention and control measures are the keys to reduce the incidence of JE.

To explore the relationship between meteorological factors and incidences of fever,thrombocytopenia and leukopenia syndrome(FTLS),incidence data of FTLS in Xinyang City were collected and described.The relationship between FTLS and monthly meteorological factors such as average atmospheric pressure,average temperature,average relative humidity,average wind speed and precipitation was analyzed with simple correlation and multi-stepwise linear regression.The results showed that there was a significant negative correlation between incidence of FTLS and monthly average atmospheric pressure(P0.01),and there were significant positive correlations between monthly average temperature,monthly average relative humidity,monthly precipitation and incidence of FTLS(P0.05).The multi-stepwise regression showed that the regression equation was Y(monthly cases) =-12.70 + 0.28X_2(monthly average temperature),and the coefficient of determination was 0.76.The incidences of FTLS are correlated with temperature.

Objective To isolate and identify arboviruses from mosquito pools in Xinyang city of Henan province in 2009.MethodsMosquitoes were collected from Xinyang city of Henan province in 2009.Isolated viruses were inoculated into BHK-21 cells and identified the virus species by PCR and sequencing.ResultsA total of 3 050 mosquitoes were collected and three isolates produced CPE in BHK-21 cell culture with two isolates were identified as Getah virus and one unknown strain,respectively.ConclusionsTwo strains of Getah virus and one unknown strain were isolated from mosquitoes and reported first time in Xinyang city of Henan province.

Objective To analyze pathogen species and prevalent characteristics of the viral encephalitis in some areas of Henan province.Methods Surveillance data on all viral encephalitis(VE)cases diagnosed in 2008 were collected from Xinxiang,Kaifeng,and Luoyang.The blood and cerebrospinal fluid(CSF) samples were collected from the cases and IgM antibody against Japanese encephalitis(JE) was detected with enzyme-linked immunosorbent assay(ELISA).The antibody of other virus was detected with reverse transciption-PCR(RT-PCR).Cell culture separation was conducted for IgM antibody negative specimens.Results A total of 215 viral encephalitis cases were reported and 47(21.86%) cases were positive for IgM antibody against JE.A total of 24(14.29%) intestinal virus strains were isolated from the cerebrospinal fluid of 168 IgM antibody negative cases.Among the the virus,there were twelve of ECHO30,seven of ECHO6,four of ECHO25,and one of CoxB5.The 47 JE and 168 intestinal virus and other viral encephalitis cases occurred mainly in July to September,accounting for 93.62% and 70.24% of the cases.The 0-14 years old group of JE and intestinal virus and other virus encephalitis cases occurred mainly in Xinxiang(91.91% and 92.31%) and Kaifeng(97.92% and 98.41%).The 0-14 years old cases of intestinal virus and other viral encephalitis cases accounted for 92.99% of all cases in Luoyang city and≥15 years old cases of JE significantly increased(56.52%).The incidences of JE,intestinal virus,and other viral encephalitis were significantly different between 0-14 years old group and≥15 years old group(χ2= 21.13,P0.05).The JE cases were mainly farmers in Luoyang and the JE cases of intestinal virus and other viral encephalitis in Xinxiang and Kaifeng were mostly scattered children,children in and kindergarten,or students.Conclusion Japanese encephalitis virus and intestinal virus are main pathogens of viral encephalitis in Xinxiang,Kaifeng,and Luoyang.The peak season of the intestinal virus and other viral encephalitis was the same as that of JE.The age and occupation distribution of the cases are different in different areas.

Objective To analyze the neutralizing antibody levels against epidemic Japanese encephalitis(JE) virus as well as the morbidity rates of JE in two counties in Henan Province,China.Methods The neutralizing antibody levels against JE virus as well as the morbidity rates of JE in Xi County,Xinyang City and in Xin′an County,Luoyang City were monitored.Healthy populations in each county were divided into various age groups and determined for serum neutralizing antibody levels against JE by microneutralization test before(in May) and after(in November) epidemic season respectively,based on which the neutralizing antibody positive rates and morbidity rates as well as relationship to age were analyzed.Results The mean neutralizing antibody positive rate against JE in healthy populations in Xi County reached 69.96% before epidemic season,which increased gradually with the increasing age,and was 100% in those at ages of more than 20 years.However,in Xin′an County,the neutralizing antibody positive rate varied with the age,which showed two peak values in the populations at ages of 1 ～ 2 and 20 ～ 59 years respectively.Cases of JE were observed in children at ages of less than 5 years in both the counties,while in both children and adults in Xin′an County.The morbidity rate of JE in population at ages of more than 80 years in Xin′an County reached 26.93%.Conclusion In the two counties in Henan Province,the serum neutralizing antibody positive rates were closely related to the morbidity rates of JE,which showed significant difference in the populations at various ages and in those at the same age group in two counties.

OBJECTIVE:To analyze and summarize the clinical characteristics, experience of diagnosis and treatment of cases infected by new bunyavirus, which occurred in Henan province in 2010.METHODS:The clinical characteristics and effect of diagnosis and treatment of 5 cases were analyzed using descriptive epidemiological method. Blood specimens were detected by RT-PCR and pathogen separation.RESULTS:PCR testing was positive for all 5 cases. New bunyavirus were isolated from 2 cases. In 5 cases, fever (5/5), the whole body aches (5/5), fatigue (5/5), anorexia (5/5), nausea (5/5), the chills (4/5), cough (4/5), expectoration (4/5), vomiting (3/5), conjunctival hyperemia (3/5); Leukocyte reduction (5/5), thrombocytopenia (5/5), elevated alanine aminotransferase (4/5), elevated aspartate aminotransferase (4/5), elevated lactate dehydrogenase (5/5), creatine kinase elevations (4/5), urinary protein (3/5). By symptomatic and supportive treatment and prophylactic antibiotics, the first case died and the other 4 cases were cured. The average course of disease was 15.4 days.CONCLUSION:Cases infected by new bunyavirus have complicated clinical feature and multiple organ damage. If symptomatic treatment is in time, prognosis will be good.

OBJECTIVE To analyze the epidemiological characteristics and risk factors of Japanese encephalitis (JE) in Henan province. METHODS Epidemiological characteristics and related factors of JE cases in Henan province from 2006 to 2010 were analyzed with descriptive epidemiological method and JE IgM antibodies of the serum or cerebrospinal fluid of the cases were detected by ELISA. RESULTS 3099 cases were reported in Henan province from 2006 to 2010. The incidence fluctuated from 0.39/100 000 to 1.08/100 000, and the incidence rate was decreasing. Patients were concentrated mainly in Xinyang, Nanyang and Luoyang cities, which accounted for 60.12% of the total. The peak season was in July-September, accounted for 93.26% of all the cases. Most cases were in 0 - 14 year old (83.61%) in the whole province. However, in Luoyang city, number of cases in the ≥ 15 year old group, had an obvious increase (57.63%). Compared with the provincial data, significant difference was found between the two ≥ 15 year old groups (χ(2) = 330.0341, P < 0.05) statistically. 20.23% of the JE cases were vaccinated but 75.54% of them did not complete the whole course. 79.77% of the cases were not sure if they had received the vaccination. 42.98% of the JE cases were confirmed through laboratory tests but other 45.95% of them were clinically diagnosed, with the rest 11.07% were suspected cases. CONCLUSION The distribution of JE cases showed seasonal, regional characteristics and crowd differences in Henan province. Basic immunization and the program on strengthening immunization of JE should be further standardized. The laboratory diagnosis rate of JE cases should be further improved.