Cohen 1973年提到Hairston(1965)和Sturrock等(1971)曾先后应用Muench(1959)催化模式(注)分析人体血吸虫病和螺类血吸虫病的年龄感染率的曲线,但未计及由于感染引起的选择性死亡率(∈)。这种死亡率无疑在螺蛳群体中是存在的,而且用Pan的数据,Cohen证明了它基本上修改了从圣卢西亚的数据催化曲线分析所得到的两个参数的估计,增加了感染力(α),而减小了 Cohen mentioned in 1973 that Hairston (1965) and Sturrock et al. (1971) used the Muench (1959) catalytic model (Note) to analyze the age-related infection rates of human schistosomiasis and snail schistosomiasis, The selective mortality (∈). This mortality is undoubtedly present in the snail population, and with Pan’s data, Cohen demonstrated that it substantially modified the estimates of the two parameters derived from the data catalysis of Saint Lucia and increased the infectivity ( α), but decreased