[Distribution characteristics of deposited eggs and pathological changes in viscera of New Zealand white rabbits infected with Schistosoma japonicum at different time].

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: 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.
Results: 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 hyperemia, 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: 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.