The Study Of Serological Bayesian Model To Evaluate The Epidemiological Situation Of Schistosomiasis Japonica

At present,the Schistosomasis japonica is mainly endemic in China's five south provinces(Anhui,Hubei,Hunan,Jiangsu,Jiangxi)and 2 mountains provinces(Sichuan,Yunnan).There are many differences in the detection efficacy of serological diagnosis methods of schistosomiasis.There are significant differences of the detection efficiency between the different epidemic types,degrees,age and sex.With the development of schistosomiasis prevention and control,the human infection rate decreased significantly,the low sensitivity of stool examination method has become increasingly prominent.Therefore,it is essential to establish the statistical method for accurately estimating the human infection rate of schistosomiasis,assessing changes of epidemiological situation and development of strategies.In this study,the meta-analysis was used to obtain a high detection test method.The Bayesian hierarchical model was used to built the estimation mode schistosomiasis including the sensitivity and specificity of different sex and age group.At last,the model was use to evaluate the control effect was evaluated in the population of Dantu District,Zhenjiang City.First,the diagnostic effect of indirect hemagglutination test(IHA),enzyme-linked immunosorbent assay(ELISA)and dipstick dye method(DDIA)was evaluated by meta-analysis.The combined sensitivity of IHA,ELISA and DDIA was 0.83,0.87 and 0.90,respectively,and the weighted specificity was 0.69,0.60 and 0.62.The overall SROC curves under IHA,ELISA and DDIA were 0.89,0.96 and 0.92,respectively.The area under the ELISA curve is larger than that of IHA and DDIA,and the diagnostic efficiency of ELISA is high.Then 8248 sample populations were collected from 7 survey sites in Jiangxi,Anhui and Hubei provinces,and Kato-Katz etiological examination and ELISA serological tests were carried out.The sensitivity and specificity of male for 6 ~,10 ~,20 ~,30 ~,30 ~,40 ~,50 ~ and 60 ~ age group were 0.7500,0.9500,1.0000,1.0000,0.9667,0.9512,1.0000,and 0.8898,0.6958,0.5105.The sensitivity and specificity of female were 0.5000,0.8889,0.0000,0.9048,1.0000,0.9615,1.0000 and 0.8960,0.8193,0.6995,0.4930,0.4631,0.5086,0.5505.The sensitivity(t = 16.231,P <0.01)and specificity(t = 7.727,P <0.01)were statistically different between the different age groups.With the increase of age,the sensitivity of males and females were also increasing from 6 to 30 years and then became stable,the specificity showed a downward trend.The specificity of male were lower than female at the same age.Secondly,based on the a priori information obtained in the first part,the 95% confidence interval of sensitivity and specificity for different age and gender groups were obtained by using the Wilson interval algorithm.The stratified sampling was used,namely,the nested structure data.The hierarchical Bayesian model was selected to built the estimation model of schistosomiasis,and then the validation and sensitivity analysis of the model were carried out by the the tur data and parameters adjustment of sensitivity and specificity.The difference between the estimated infection rate and the real infection rate was not statistically significant,and suggested that the model could be used to estimate the real infection situation of the population.Finally,the ELISA method were used to test the serum bank for 5 consecutive years(2011-2015)in the monitoring site in Dantu District,Zhenjiang City,Jiangsu Province.2180 serum samples were detected,and the positive rate was 37.38% in 2012 and 7.36% in 2015.The positive rate of serum was decreased,and the positive rate of serology was statistically different(P = 0.0001,P <0.05).The estimated infection rate of human was 1.288%,1.456%,1.032%,1.485% and 1.358% respectively,and there was no significant difference(P = 0.998,P> 0.05).The risk factors for schistosomiasis transmission in this region may remain in 2011-2015,and there is a need to continue to strengthen schistosomiasis risk monitoring,and prevention and control work needs to be further strengthened.In summary,the ELISA method had a high diagnostic efficacy,and there was a significant difference in sensitivity and specificity between different age and sex.The serological Bayesian model of schistosomiasis including a priori information such as age and sex,can accurately estimate the infection rate of schistosomiasis in the population using serological data.