在同一地区感染的曼氏血吸虫病人为何有轻重不等的临床表现?有人认为.除其他影响因素外,可能与血吸虫的不同株有关。有人在实验中分别取肝脾肿大型和肠型病人排出的曼氏血吸虫虫卵,孵化后再感染光滑双脐螺,发现前者比后者产生较多的尾 Why do human schistosoma mansoni, which is infected in the same area, have different clinical manifestations? Some people think that it may be related to different strains of schistosome, among other factors. Some people in the experiment were taken hepatosplenomegaly and intestinal type of Schistosoma mansoni eggs, hatch and then infected with smooth double umbilical snail, found that the former than the latter to produce more tail