湖北省湖区牛日本血吸虫感染与再感染及其危险因素的研究

为研究湖滩型日本血吸虫病中重度流行区化疗后牛群血吸虫感染、再感染及其危险因素,采用在观察试区,以34例感染牛经吡喹酮治疗后虫卵转为阴性的30头牛为"再感染"研究对象,98例粪检阴性牛群作为"感染"研究对象,追踪观察2组牛群在一个感染季节后的再感染情况,并调查其接触疫水情况以及当地螺情和疫水变化情况等因素,再对其进行单因素分析和多因素非条件Logistic回归分析。结果显示,基线感染率为20.26%,经过一个感染季节后,标准化感染率为10.01%,标准化再感染率高达20.62%,再感染率已恢复到化疗前牛群感染水平,其中黄牛再感染率(26.66%)高于水牛感染率(13.33%)。接触疫水处水体尾蚴密度、年龄、6～9月疫水接触指数、牧地距阳性螺点距离是再感染发生的主要危险因素。接触疫水处水体尾蚴密度、牛采食和6～9月疫水接触指数是血吸虫病感染的主要危险因素。本研究表明,在日本血吸虫病重度流行区存在较快感染和再感染趋势,初步揭示了感染和再感染的主要危险因素。

Infection and reinfection of Schistosoma japonicum in the cattle in the lake beach areas of Hubei Province and hazard factors

In order to investigate infection,reinfection and the risk factors of schistosomiasis japonica after chemotherapy in the mid-epidemic-striken lake beach areas,an experiment was carried out.In which 30 out of the 34 infectious cattle after treated with praziquantel and turned to be nagtive were used as the "reinfection" subject,and 98 cattle turned to be nagtive were used the "infection" subject.The reinfection of the two groups of cattle in the same infection season was traced,and the associated factors were investigated.In addition,the single factor analysis and the mutifactor unconditional logistic regression analysis were carried out.The result indicated that the basic infectious rate was 20.26%.After one transmission season,the standardized infection rate reduced to 10.01% and the standardized reinfection rate reached as high as 20.62%,which returned to the infectious level before using chemotherapy.The reinfection rate(26.66%)of the acalper was higher than the infection rate(13.33%)in the buffalo.The main factors that cause the reinfection are age,index of contacting contagious water from June to September,the distance between residence and infected snail spot.The main risk factors of the schistosomiasis infection are cercaria density in water,occupation and index of contacting contagious water from June to September.Together,the trend to quick infection and the reinfection exists in the mid-epidemic-striken lake beach areas.