Roepstorff A, Eriksen L, Slotved H C, Nansen P
Danish Centre for Experimental Parasitology, Royal Veterinary and Agricultural University, Frederiksberg, Copenhagen, Denmark.
Parasitology. 1997 Oct;115 ( Pt 4):443-52. doi: 10.1017/s0031182097001480.
To study population kinetics during primary Ascaris suum infections, 3 groups of 52 pigs each were inoculated with 100, 1000, or 10,000 infective eggs. In all groups, the majority of larvae was found in the liver on day 3 post inoculation (p.i.) and in the lungs on day 7 p.i. Liver white spots, caused by migrating larvae, were most numerous at day 7 p.i., whereafter they gradually healed, and only low numbers of granulation-tissue type white spots and lymphonodular white spots persisted at days 21-56 p.i. Independent of dose level, 47-58% of the inoculated eggs were recovered as larvae in the small intestine on day 10 p.i., but most larvae were eliminated at days 17-21 p.i. This elimination started earlier and removed a higher percentage of the worms with increasing inoculation dose, resulting in small strongly aggregated worm populations by day 28 p.i. (k of the negative binomial distribution was low: 0.2-0.4) without significant differences between groups. Thus, overdispersion, which is a characteristic of both porcine and human ascarosis, is found here under experimental conditions where aggregation factors like host behaviour, transmission rate, host status etc have been partly or totally controlled.
为研究猪蛔虫初次感染期间的种群动力学，将3组猪（每组52头）分别接种100、1000或10000个感染性虫卵。在所有组中，接种后第3天多数幼虫见于肝脏，接种后第7天见于肺脏。由移行幼虫引起的肝脏白斑在接种后第7天最多，此后逐渐愈合，在接种后第21至56天仅残留少量肉芽组织型白斑和淋巴小结型白斑。与剂量水平无关，接种后第10天，47%至58%的接种虫卵在小肠内以幼虫形式回收，但多数幼虫在接种后第17至21天被清除。随着接种剂量增加，这种清除开始得更早，清除的虫体比例更高，到接种后第28天形成小的高度聚集的虫群体（负二项分布的k值较低：0.2至0.4），各组间无显著差异。因此，在宿主行为、传播率、宿主状态等聚集因素已部分或完全得到控制的实验条件下，发现了猪蛔虫病和人蛔虫病共有的超分散现象。
