| Objective:To analyze the change of schistosomiasis from 2005 to 2006,and to analyze discuss the risk factors of schistosomiasis using multilevel models.Methods:A basing investigating in 16 villages in Hunan province was conducted in 2005,and followe up study was carried out in 2006.we first screened the schistosomiasis using indirect hemagglutination test (IHA)and then used the Kato-Katz method to examine IHA positive cases.Hatching assays were done for domestic animals.The standard environment sampling method or the system sampling method was adopted to detect the water-snail.Information risk factors was collected by visiting family and referring official numerical data.Chi-square test and student's t-test were used to compare the change of prevalence of schistosomiasis.Chi-square test,multilevel models and logistic regression model were used to analyze the risk factors of schistosomiasis. The software used in statistics analysis was SPSS 13.0 and HLM6.04. The statistical significance level was set atα=0.05.Result:A total of 10245 residents in the 16 villages were investigated in 2005.Among 2457 were positive for schistosomiasis antibody(22.46%),and a total of 394 individuals were found eggs of schistosomiasis.With average positive rate of 4.07%.7482 residents were followed up in 2006,and the average positive rate was 3.39%.The intensity of infection(EPG)were lower in 2006 compared with the results in 2005 with the exception of EPG geometric mean(GM)of patients,and the population arithmetic mean(AM)showed significance (P＜0.05).The rate of new infection of schistosomiasis was 2.52%,and continued positive rate was 15.99%.Compared with 2005,the rate of infection of domestic animals reduced by 18.24%in 2006;The density of live snail was also reduced,but the density of infected snail and the rate of snail infection rose from 2005 to 2006.Univariate analysis showed that sex,age,occupation,the types of prevalence,region,the average income,the area of paddy field,drinking water,the proportion of innocuous lavatory,the rate of domestic animals infection,the density of infected snail,the average temperature in June, the rainfall in April,September and October were associated with infection of schistosomiasis.Multilevel logistic analysis showed aider controlling confounding factors,the probability of schistosomiasis for male was 2.73(2.18,3.41)times as much as that for the female,and the rate waried greatly by age of the residents.Compared with other occupation,the probability of schistosomiasis of the fishermen was 4.27 (2.14,8.50)times greater.For people in the Embankment,flood plain and inner dike,the probabilities of schistosomiasis are 8.64(1.83, 40.70),18.77(3.80,92.64),6.32(1.07,37.30)times as much as the people in Hill,respectively.The probability of schistosomiasis for the people in the areas where a crowd of people drink the water of ditches and ponds is 4.88(2.65,8.99)times as much as that for the people in the areas where no one drink it.The probability of schistosomiasis for the people in the areas where the harmless restroom proportion is smaller than 50%is 3.82(1.62,9.02)times greater than that for the people in the areas where the proportion is larger than 50%. The probability of schistosomiasis for the people in the areas where the average rainfall is over 100 mm in April is 3.26(1.77,6.01)times greater than that for the people in the areas where the average rainfall is below 100 mm.The probability of schistosomiasis for the people in the areas where the average temperature is greater than 27 Degree Celsius in June is 3.94(1.85,8.40)times greater than that for the people in the areas where the average temperature is lower than 27 Degree Celsius areas.Conclusions:There is a reduction of schistosomiasis in 2006 as compared with 2005.Sex,age,occupation,the types of prevalence, drinking water,the proportion of innocuous lavatory,the average temperature in June,the rainfall in April are associated with infection of schistosomiasis. |
