日本血吸虫感染不同相容性动物宿主的比较研究

目的 了解日本血吸虫感染不同动物宿主（包括天然宿主和实验动物宿主）后的虫体发育和宿主组织病理变化差异。方法 以黄牛、水牛、山羊、BALB/c小鼠、Wistar大鼠和新西兰大白兔为对象，同一时间人工感染相同来源的日本血吸虫尾蚴，收集感染后相同日龄的虫体（49d），对虫体发育进行比较，对宿主的肝脏病变进行比较，并对黄牛、水牛和山羊的肝脏进行了病理切片的观察和比较。 结果 不同动物宿主来源的虫体的长度、宽度和发育情况存在着差异，总体来说是适宜宿主体内的虫体长度明显长于非适宜宿主体内的虫体长度，雌虫长于雄虫（Wistar大鼠来源的虫体例外）。发育情况除了Wistar大鼠来源的虫体未发育成熟，其余动物来源虫体均发育成成虫。六种动物宿主的肝脏病变存在很大的差异，适宜宿主感染后肝脏布满虫卵结节，病变尤其严重；而非适宜宿主的肝脏只有少量虫卵结节（水牛），或者几乎看不到虫卵结节（Wistar大鼠）。天然宿主肝脏病理观察发现，黄牛组和山羊组肝脏组织炎性细胞明显增多且聚集，虫卵周围有大量嗜酸性细胞浸润，多量炎性淋巴细胞聚集浸润，形成典型条纹状嗜伊红沉淀物；而水牛组的肝细胞无变性、无炎症细胞的聚集浸润, 小叶结构完整。 结论 日本血吸虫对黄牛、山羊、BALB/c小鼠和新西兰大白兔的易感性高于水牛和Wistar大鼠，对前四种动物的致病性也强于后两种，本文为进一步了解日本血吸虫对不同终末宿主的感染差异提供了一些参考数据。

Comparative study on Schistosoma japonicum infection with different permissive animal hosts

In order to know the difference for Schistosoma japonicum(S.j) infection with different animal hosts, including natural hosts and experimental animal hosts, by worm development, worm morphology and host’s histopathology. We artificially infected six animal hosts(yellow cattle, water buffalo, goat, New-Zealand rabbit, BALB/c mice and Wistar rat ) with the same source of S.j cercariae. The parasites were perfused through the hepatic portal vein after infection for 49d. The male and female worms were detached manually, counted, and the length and width of the worms were measured by the same person. The results showed that the worm recovery in permissive hosts were higher than that in non-permissive hosts, and the length of the worms from permissive hosts were greater than those from non-permissive hosts. Only in Wistar rat, the parasites could not develop into maturation, parasites in other hosts all could mature, paring and lay eggs, causing liver damage in their hosts. The livers from permissive hosts were filled with many white egg nodules, composed of many egg-granulomas, while the livers from water buffalo were red with few or no egg nodules, while the livers from Wistar rat had no damage at all. The histological sections from livers of infected natural hosts, showed that in yellow cattle and goat, some hepatocytes displayed mild swelling, a large number of inflammatory cells were seen to be infiltrating and aggregating, including eosinophils and lymphocytes, and typical striped eosinophilic deposits were seen；Compared with the yellow cattle and goat, the structural integrity of the hepatic lobules was intact in the livers of infected water buffalo, there was actinomorphous distribution of hepatic cord centered on central veins, polygonal hepatocytes, no edema, no inflammatory cell infiltrated, and only scattered neutrophils and monocytes. This study provide reference data for laboratory and field studies, and understanding the relationship between S.j with different animal hosts.