Abstract: Objective Objective To study the distribution characteristics of deposited eggs and pathological changes in the viscera of animal infected with Schistosoma japonicum at different time. Methods Methods New Zealand white rabbits were infected artificially with quantitative S. japonicum miracidia，then the distribution characteristics and the hatchability of schistosome eggs as well as the pathological changes of the corresponding viscera of the rabbits 42 and 60 d post?infection were observed and compared. Re Re? ? sults sults On the 42nd day post?infection，among all the viscera observed，the percentage of eggs deposited，the number of eggs per gram and the hatchability were the highest in the liver，while on the 60th day post?infection，the tissues and organs with the highest values of the above 3 indexes were the liver，rectum and upper section of the small intestine，respectively. From 42 day to 60 day post ? infection，the liver of infected rabbits became swelling，hardening and lost elasticity，the color changed from black to dark grey，and egg nodules gradually appeared in the different sections of the small intestine，and also the mucosal hy? peremia，edema and egg nodules were seen in the colon，cecum and rectum. The lesion levels tended to be correlated with the deposition of eggs. Conclusion Conclusion The amount and the density as well as the hatching rate of deposited eggs of S. japonicum in the viscera of infected rabbits at different time are different，and the lesion level in the host is correlated with the deposition of eggs.

Key words: Schistosoma japonicum； New Zealand white rabbits；Egg；Pathological change

摘要： 目的 目的 观察感染日本血吸虫不同时间动物内脏中沉积虫卵的分布特征及组织病理变化。方法 方法 新西兰大白兔 定量人工感染血吸虫后， 比较感染后42、 60 d沉积虫卵在组织中的分布特征、 虫卵孵化率的变化以及相应部位的病理改 变。结果 结果 感染42 d时， 沉积虫卵百分比、 每克组织沉积虫卵数及沉积虫卵孵化率最高的均为肝脏； 感染60 d时， 上述3 个指标值最高的分别为肝脏、 直肠和小肠上段。从感染后42 d到60 d， 兔肝脏肿大， 且由黑色逐渐变成暗灰色并失去弹 性而硬化， 小肠各段逐渐出现虫卵结节， 结肠、 盲肠和直肠可见黏膜充血、 水肿、 结节， 病变程度与虫卵的沉积相关。结 结 论 论 新西兰大白兔感染日本血吸虫后不同时期， 不同器官组织的沉积虫卵数量、 密度及虫卵孵化率均有差异， 且沉积虫 卵的分布和宿主病理损伤程度有关。

关键词: 日本血吸虫； 新西兰大白兔； 虫卵； 病理变化