Norval R A, Andrew H R, Yunker C E
University of Florida/USAID/Zimbabwe Heartwater Research Project, Veterinary Research Laboratory, Causeway.
Vet Parasitol. 1990 Jul;36(3-4):277-83. doi: 10.1016/0304-4017(90)90039-e.
Cowdria ruminantium (heatwater) infection rates of field populations of the bont tick, Amblyomma hebraeum, were determined at two locations in the southern lowveld of Zimbabwe. At Mbizi Quarantine Station, unfed adult males and females, and nymphs were collected at intervals over a 2-year period using traps. At Lemco Ranch, engorged nymphs were collected on three occasions from weaner calves and allowed to moult to adults. The unfed ticks were fed in small pools on heartwater-susceptible sheep, some of which became infected. The infection rates of the ticks were then estimated statistically. Depending on the date of collection and locality, these rates were in the range 0.0-44.9% for males, 20.0-36.1% for females and 0.0-13.4% for nymphs. Most of these rates are considerably higher than those previously believed to occur.
在津巴布韦南部低地的两个地点测定了有角蜱（Amblyomma hebraeum）野外种群的反刍兽考德里氏体（Cowdria ruminantium，即心水病病原体）感染率。在姆比齐检疫站，在两年时间里定期使用诱捕器收集未进食的成年雄性和雌性蜱以及若虫。在莱姆科牧场，三次从断奶小牛身上收集饱血若虫，并让它们蜕皮成为成虫。将未进食的蜱放在小水池中，让它们叮咬易患心水病的绵羊，其中一些绵羊被感染。然后对蜱的感染率进行统计估计。根据收集日期和地点的不同，雄性蜱的感染率在0.0%至44.9%之间，雌性蜱为20.0%至36.1%，若虫为0.0%至13.4%。这些感染率大多远高于此前认为的发生率。
