The Investigations On The Transmission Dynamics Of Echinococcus Species In XHG-areas Of Ningxia

Objectives: Xiji, Haiyuan counties and Guyuan district(referred as XHG areas), are a high incidence of the two types of echinococcosis(AE and CE), its popular time is long and the control effect is not ideal, which significantly impacted on local public health and economic development. The objective of this study is to reveal the transmission dynamics of Echinococcus species in XHG areas. In addition, risk factors of susceptibility to infections in adolescents influenced by the eggs of Echinococcus species are identified by multivariate analysis. This is the important information for targeting at preventive measures to protect young people healthy growth in XHG areas.Methods: The visceral inspection of the animal intermediate hosts in 2008/9 and in 2012. PCR method for dog copro-DNA detection and ELISA assay for discovery of the sero-antibodies against E.g/E.m-antigens amongst ultrasound negative teenagers(caused by egg-ingestion indicating the environmental Echinococcus egg-contaminations) were carried out. ADAMU-AE and ADAMU-CE for discovery of the sero-antibodies against Eg Ag B8/1/Em18-antigens amongst the patients and the healthy persons. The data were input into SPSS 20.0 for management and analysis. Chi-square test was used for the comparisons of the different positive rates between groups. P <0.05 was considered as different significantly.Results:The investigation in Xiji revealed the infectious rates at 6.5%/4.7% and 4.3%/4.8% amongst cattle and sheep in 2008/9, respectively and insignificant differences between rates in the two years. However, in the meat market, no CE infection was found in 2012 investigation. The results showed that, amongst the 2175 dog copro-samples, the Eg-DNA positive rates of 9.87%, 6.10% and 7.00%, and the Em-DNA positive rates of 6.40%, 1.52% and 3.37% occurred in Xiji, Haiyuan counties and Guyuan district, respectively. The positive rates of the sero-antibodies against Eg-antigens were 45.46%,36.23% and 42.18%; against Em-antigens were 8.38%, 7.03% and 20.48%, respectively, amongst 5706 teenagers in the areas. The sensitivity of ADAMU-AE was 67.65%, and its specificity was 99.6%; The sensitivity of ADAMU-CE was 45.65%, and its specificity was 100%.Conclusion:The results of parasite-DNA detection from dogs, and the sero-antibody positive rates amongst teenagers provided the strong evidences that the transmission dynamics of the two types of Echinococcus species are active there. The home-slaughter of aged animals is spreading the contamination of living environments. The factor of 90% residents using untreated dog-faeces as manure fertilization may be one of the key risks for the spreading of egg-contamination and Echinococcus species transmission in study areas. ADAMU-AE and ADAMU-CE can be used to diagnosis the patients in the early stage.