Crompton D W, Keymer A E, Arnold S E
Parasitology. 1984 Apr;88 ( Pt 2):317-31.
An analysis of the frequency distribution of numbers of Moniliformis dubius in rats of an outbred strain of Wistar origin (CFHB) and feeding ad libitum on Oxoid 41B diet, showed that over-dispersion occurred regardless of the age and sex of the rats and the infective dose given (12, 20 or 40 cystacanths/rat). Over-dispersion was also shown to be independent of variability in the age and sex of the cystacanths given. The analysis demonstrated that the over-dispersion declined as the course of the infection proceeded. As expected, parasite survival was found to be age-dependent with female worms living longer, on average, than males, and both male and female worms living longer in rats given 12 as opposed to 20 cystacanths. Possible mechanisms for generating the over-dispersion observed during this work are discussed and a tentative hypothesis, invoking host heterogeneity with regard to carbohydrate availability in the small intestine, is proposed for further experimental investigation.
对源自Wistar的远交系（CFHB）大鼠进行研究，这些大鼠以Oxoid 41B饲料随意采食，分析大鼠体内串珠状棘头虫数量的频率分布，结果表明，无论大鼠的年龄、性别以及给予的感染剂量（每只大鼠12、20或40个囊尾蚴）如何，均出现了过度离散现象。过度离散还被证明与所给囊尾蚴的年龄和性别的变异性无关。分析表明，随着感染进程的推进，过度离散程度下降。正如预期的那样，发现寄生虫的存活与年龄有关，雌性蠕虫平均比雄性蠕虫存活时间更长，并且在给予12个囊尾蚴而非20个囊尾蚴的大鼠中，雄性和雌性蠕虫的存活时间都更长。讨论了在这项研究中观察到过度离散现象的可能机制，并提出了一个初步假设，即小肠中碳水化合物可用性方面的宿主异质性，以供进一步的实验研究。
