Epidemiology And Pathology On Sparganosis In Frog(Rana Nigromaculata) In Huaxi, Guiyang

Objective:To investigate the epidemiology of sparganosis in frog(Rana nigromaculata)in Huaxi,Guiyang and to examine the histopathology of the frog sparganosis lersion,especially to ditect possible mast cell reaction in the sparganosis lesion.Materials and Methods:A survey on the natural infection atatus of sparganosis in frog Rana nigromaculata from huaxi distract of Guiyang,Guizhou was carried out and 818 frog were collected and examined.For specie indetification,the tapeworm cestode obtained from an experimentally-infected dog by the sparganum larva from the frogs was examined under light and electron microscopy.The sere collectes from the natural infected rabbits by the sparganum larva from the frogs were tested by enzyme-linked immunoserobent assay(ELISA)used in human sparganosis detection.The hhistopathological changes of the sparganosis lesion were observed with HE and toluidine blue staining methods.Results:Among 818 frogs examined,16.01%(131/818) were infected with Sparganum larva in range of 1 to 113 larva per affected frog(the average intensity is 3.44 per frog)and the highest is 131 larva collected from one frog.The tapeworm cestode obtained from an infected dog by the apargamum larva was determinated as Spirometra mansoni.The positive rate for anti-sparganum antibody in infected rabbits by the sparganum larva was 100%and none positive reaction could be detected in the natural-infected frogs.Characteristic lesions included cavitary necrosis by immigrating of the larvae,granulomatou reaction by infratration of eosinophils,neutrophils,macrophages and lymphoid cells,and proliferation of epithelioid cells and fibroblast cells.In a few cases entirety fragmatation following death pf the larva and calcareous bodies out of the larva were the important findings in present study.Remarkable proliferation of mast cells in granulomatous lesion.It was noted firstly that mast cells proliferated in the granulomatous lesion which intend to around the wall of the cavitary necrosis by moving of the larvas,and also diffused among inframmation cells and fibroblast cells of the lesion.Conclusion:1)Huaxi district of Guiyang is still a highly endemic ares of frog sparganosis mansoni;2)Like human sparganosis,the histopathological changes of frog spargansis is characteristic eosinophic granulomatous cavitary lesion;3)ELISA can be used to detect animal sparganosis;4) There are close relationship between mast cell reaction and the forming of the eosinophil grannulomatous lesion in frog sparganosis.