Analysis About Epidemiological Characteristics And Factors Of HFRS In Hebei Province

Objective: The purpose of this study was to understand the epidemiccharacteristics of hemorrhangic fever with renal syndrome (HFRS) in HebeiProvince from1996to2011,to explore the factors related to HFRS, to preventand control HFRS effectively, and to provided basis for establishment of earlywarning system about Rodent-borne diseases.Methods:1The epidemiological data of HFRS and the data of population,meteorology, remote sensing aspects in cities of Hebei Province during1996and2011were collected. The epidemiological data include the distributioncharacteristics of person, region, season and the characteristics of categorycomposition, density, the carry virus rate of rat.2The data were summarized through using EXCEL form, and wereanalyzed by descriptive study. Through using the statistical software ofSPSS13.0to complete the correlation analysis and Multivariate linear analysis.Results:137022cases of HFRS were reported from1996to2011.The averageannual incidence rate was3.43/100000.The epidemic situation totallyPresented an declining tendency. The incidence got into low level since2004,and maintained less than1/100000in recent years.2Distribution in season of HFRS Presented two peaks, but the main peakseason was spring. Analyzing the proportion of HFRS cases in season, therewas a declining tendency from March to June, while there was a ascendingtendency from November to January.3HFRS happened in all age groups, but mainly concentrated in the20-49years old; Incidence ratio of male and female was2.41:1, and the proportionremained unchanged basically; The occupations of high incidence were farmers, students, workers and cadre staffs, mainly farmers. The proportion offarmers and students showed a declining tendency, while workers showed aascending tendency with the change of time.4HFRS happened in all cities of Hebei Province from1996-2011,but thedistribution was uneven. According to the incidence of HFRS in each year inall cities, Hengshui,Shijiazhuang and Baoding were the high incidence areasfrom1996to1998.Since1999,the number of cases in Hengshui decreasedrapidly, but the number in Tangshan and Baoding increased sharply. The peakof incidence were at Shijiazhuang, Tangshan, Cangzhou, Baoding during2000and2003, but mainly in Shijiazhuang. After2004, Qinhuangdao and Tangshanwere the main high incidence area currently.5The average density of rat was1.79%in Hebei province from2003to2011,of which residential area was2.28%and field area was1.18%.Theyshowed a declining trend over time. The carry virus rate of rat was3.56%inaverage, of which residential area was4.13%and field area was1.68%.Therewere obvious difference in residential area and field about density and thecarry virus rate of ratThrough Classifying and identifying the composition of rodent in fourHFRS national monitoring points in Hebei province from2005to2011,Rattusnorvegicus was the dominant host animals not only in residential area but alsoin field. There was significant difference between residential area and field’scomposition of rodent. The yearly incidence of HFRS correlated positivelywith density and the carry virus rate of rat in residential area and field,respectively.6Since the intervention by vaccine immunization in10countries, theincidence rate dropped obviously.7There was a negative correlation between the average incidence rateand the average NDVI value yearly in Hebei province.8It was a negative correlation between the average incidence rate andprecipitation yearly in Hebei province, and it was no statistically significantcorrelation with mean temperature and sunshine duration. 9NDVI value, precipitation, average temperature, density and the carryvirus rate of rat were selected to analyze with incidence rate of HFRS bymultiple linear regression. Finally all variables enter the regression modelwhich showed statistical significance.Conclusions:1The cases of HFRS occure mainly in spring, but the peak of wintershows a ascending tendency.20-49year-old male is the high risk population,and mainly the farmers. The epidemic situation distributes not only widely butalso concentrated relatively. At present, the cases mainly locate inQinhuangdao and Tangshan. The epidemic situation of HFRS is at low level inrecent years.2Rattus norvegicus is the dominant host animals of Hebei province. Thedensity and the carry virus rate of rat can influence the incidence rate of HFRSdirectly.3The intervention by vaccine immunization can reduce the incidence rateof HFRS effectively.4The incidence rate of HFRS is also affected by NDVI value,precipitation, temperature.5The incidence rate of HFRS is related to NDVI value, precipitation,temperature, density and the carry virus rate of rat by multiple linearregression.