卫氏并殖吸虫尾蚴经口感染的传播途径研究

Study on transmission route of cercariae of Paragonimus westermani through oral infection

目的了解皖南山区卫氏并殖吸虫尾蚴经口感染家犬及SD大鼠后特异抗体、虫卵及虫体变化情况,探索卫氏并殖吸虫感染新传播途径。方法自安徽省休宁县收集卫氏并殖吸虫尾蚴和囊蚴,分别经口感染家犬和SD大鼠,常规饲养。收集感染动物血清,ELISA法检测特异性IgM和IgG抗体;收集粪便,检测并殖吸虫虫卵。感染后30周剖杀,检获肺脏或肌肉中并殖吸虫成虫或童虫,比较分析尾蚴实验组和囊蚴对照组得虫率的差异。结果实验组家犬感染并殖吸虫尾蚴后血清IgM和IgG抗体与囊蚴对照组的抗体变化规律一致,仅IgM抗体存在时间较短;实验组SD大鼠感染并殖吸虫尾蚴后血清IgM抗体存在时间和IgG的OD值高水平维持时间均较囊蚴对照组大鼠短。实验组和囊蚴对照组家犬粪便中均检出并殖吸虫虫卵,肺脏中查到并殖吸虫成虫,两组得虫率差异有统计学意义(P<0.05)。实验组和囊蚴对照组SD大鼠粪便中均未查到虫卵,在其肌肉中均发现并殖吸虫童虫,两组得虫率差异无统计学意义(P>0.05)。结论皖南山区卫氏并殖吸虫尾蚴可经口感染家犬和SD大鼠,为当地居民并殖吸虫感染新途径的探索和防治措施的制定奠定了理论基础。

Objective To investigate the changes of specific antibodies,eggs and bodies of Paragonimus westermani after its cercariae were orally infected with dogs and SD rats,and to explore a new transmission route of P.westermani infection of southern Anhui province.Methods Cercariae and metacercariae of P.westermani were collected from Xiuning County,Anhui Province,and infected dogs and SD rats were fed orally,respectively.Serum of infected animals was collected every week,and specific IgM and IgG antibodies were detected by ELISA.At the same time,feces were collected and P.westermani eggs were detected.After 30 weeks of infection,the adult and larvae of P.westermani were collected from lung or muscle,count and the difference of recovery rate between cercariae group and control group was compared.Results The IgM of the dogs in the experimental group was positive at the 4th to 5th week,and was negative at the 18th week.The IgG of was positive at the 12th to 13th week,and still positive at the 30th week.The IgM and IgG antibodies of the dogs in the experimental group were consistent with those in the control group,but the IgM antibodies existed for a short time.The IgM of the SD rats in the experimental group was positive at the 2th to 3th week,and was negative at the 13th to 14th week.Compared with the control group,SD rats in the experimental group had shorter time of IgM antibody and shorter time of maintaining high OD value of IgG.The eggs of P.westermani were detected in feces of dogs in the experimental group and the control group,but were not found in the feces of SD rats both the experimental group and the control group.The adult and larvae of P.westermani were collected from lung of dogs in the experimental group and the control group,the recovery rate was 13.83%and 35.00%respectively,and there was statistical significance between the two groups(P0.05).The larvae of P.westermani were collected from muscle of SD rats in the experimental group and the control group,the recovery rate was 10.00%and 14.20%respectively,and there was no statistical significance between the two groups(P0.05).Conclusion The cercariae of P.westermani can infect dogs and SD rats orally in southern Anhui Province,which lays a theoretical foundation for the exploration of new ways of P.westermani infection and the formulation of control measures.