Study On Fecal Environmental Pollution Of Echinococcus Difinitive Host And Influencing Factors In Maqin County,Qinghai Province

Objective:To investigate the positive fecal rate,fecal density,and fecal positive density of echinococcus in different definitive hosts in Maqin county of Qinghai province,and clarify their spatial distribution characteristics.To establish statistical models,and analyze the environmental influence factors of definitive host fecal pollution in field environment.It provides a scientific reference basis for strategies and measures to eliminate echinococcosis in Qinghai-Tibet Plateau.Methods:To investigate the fecal environmental pollution of definitive hosts of echinococcus in field environment of Xueshan and Dawu township of Maqing county of Qinghai province in October 2018,May 2019 and September 2019.Mechanical sampling was conducted at approximately 2km intervals along the township road,investigate 116 survey points,cover the different types of environmental index includ classification of landform,pasture type,the height of grass,vegetation coverage,the density of the intermediate host,vegetational form and the center of coordinate of latitude and longitude of survey points.To search to the naked eye and collect all the dog’s,foxes’,wolves;faeces in the survey points,use double antibody sandwich ELISA to detect echinococcus antigen in faeces.Statistics the fecal pollution of the definitive host of echinococcus in the study area,use χ2 test,rank sum test,Fisher’s exact probability test and Nemenyi multiple comparison to analyze the distribution characteristics of fecal pollution in dogs,foxes and wolves in different environments.Use dynamic different method to analyze the distribution type of positive fecal quantity of the difinitive host of echinococcus in field environment.Use Logistic regression model and negative binomial regression model to analyze the influencing factors of fecal pollution of the definitive host of echinococcus in field environment.Results:The fecal rate at 116 survey points was 51.72%(60/116),and the positive fecal distribution rate at 116 survey points was 10.34%(12/116).Collecte a total of 252 fecal samples from the definitive host,among which the proportions of fox faeces,wolf faeces and dog faeces were 63.89%(161/252),11.90%(30/252)and 24.21%(61/252),respectively.The all fecal positive rate was 6.35%(16/252)by ELISA,and the fecal positive rates of fox,wolf and dog were 3.73%(6/161),6.67%(2/30)and 13.11%(8/61),respectively.The fecal positive rate ranged from 5.66%(3/53)～100%(3/3).In positive feces,the ELISA OD value was 0.327～0.5094,the average value was 0.4015.The fecal density and positive fecal density at all survey points showed a partial peak distribution,with median values of 1/10000m2 and 0/1000m2,mean values of 2.17/10000m2 and 0.14/1 0000m2,and maximum values of 53/10000m2 and 3/10000m2,respectively.Fecal positive rate and positive feces density in the villages have statistical significance under the group(P<0.05),the Xueshan of fecal positive rate and positive feces density were greater than Dawu(P<0.05),and different definitive hosts of fecal positive rate was statistically significant(P<0.05),the foxes and dogs feces were 3.73%,13.11%in the total sample,respectively,the difference was statistically significant(P<0.05);The fecal positive rates of foxes and dogs in Xueshan were 5.63%and 28.57%,respectively,the difference was statistically significant(P<0.05)Logistic regression model showed that,with other independent variables unchanged,the probability of echinococcus eventual host-positive fecal pollution increased by 1.356 times for every increase of canines feces in the survey point.The negative binomial regression model showed that,with other independent variables unchanged,the number of echinococcus definitive host positive feces increased by 1.058 for every increase of canines feces in the survey point.Conclusion:The fecal pollution of the definitive hosts of echinococcus is serious in Maqing county of Qinghai province,which is characterized by a large number and wide distribution of dog faeces and a high infection rate of fox faeces.It is suggested that the role of fox as the source of infection should not be neglected in controlling or spreading echinococcosis.The results of this study can provide valuable reference for further implementing the strategies and measures to control the source of infection in similar areas of Qinghai-Tibet Plateau.