Meek A H, Morris R S
Aust Vet J. 1979 Feb;55(2):61-4. doi: 10.1111/j.1751-0813.1979.tb15163.x.
The development of flukes that resulted from a challenge dose of 175 F. hepatica metacercariae was compared in 4 groups of sheep that were maintained under grazing conditions on fluke-free pasture. One group had been previously uninfected and all subgroups of each of the other 3 groups had been exposed to one of a range of previous doses of metacercariae. The preliminary infections of 2 of the 3 groups had been terminated respectively after 7 and 14 weeks. The third previously infected group had received its preliminary infection as 2 doses of metacercariae, 7 weeks apart. The latter infection had been terminated after 14 weeks. No appreciable differences in the mean numbers, length, prepatent period or fecundity of flukes, established as a result of the challenge dose of metacercariae, were detected between the control group and the 3 previously infected groups. It was concluded that under the conditions of the present experiment no evidence was detected that would suggest that previous infection with F. hepatica conferred any significant resistance to a future challenge.
在无吸虫的牧场上放牧的4组绵羊中，比较了因175只肝片吸虫囊蚴攻击剂量而导致的吸虫发育情况。一组先前未感染，其他3组中的每个亚组都曾接触过一系列先前剂量的囊蚴。3组中的2组的初次感染分别在7周和14周后终止。第三组先前感染的绵羊接受了2剂囊蚴的初次感染，间隔7周。后一次感染在14周后终止。在对照组和3个先前感染的组之间，未检测到因囊蚴攻击剂量而形成的吸虫在平均数量、长度、潜伏期或繁殖力方面有明显差异。得出的结论是，在本实验条件下，未检测到任何证据表明先前感染肝片吸虫会对未来的攻击产生任何显著的抵抗力。
