Norval R A, Peter T, Meltzer M I
Department of Infectious Diseases, College of Veterinary Medicine, University of Florida, Gainesville 32611-0633.
Exp Appl Acarol. 1992 Sep;15(3):145-52. doi: 10.1007/BF01195787.
Losses in domestic ruminants caused by heartwater (Cowdria ruminantium infection) in Zimbabwe and Mozambique are greater when the vector is Amblyomma hebraeum than when the vector is A. variegatum. It has been suggested that the epidemiology of the disease may be influenced by the rates at which unfed adults of these two tick species attach to uninfested hosts (i.e. in the absence of the male-produced aggregation-attachment pheromone [AAP]). In this study we confined unfed males of A. hebraeum and A. variegatum on uninfested cattle, sheep and rabbits and recorded their attachment rates. Males of both species attached more rapidly on cattle than on sheep or rabbits. Males of A. hebraeum attached more rapidly than males of A. variegatum on all three host species. The differences in the attachment rates between the two species were much greater on sheep and rabbits than on cattle. The findings suggest that in the absence of AAP, pioneer males of both tick species may attach to cattle, and pioneer males of A. hebraeum may also attach to sheep. The differences in the attachment rates of A. hebraeum and A. variegatum provide a possible explanation for observed differences in the epidemiology of heartwater associated with these two vector species.
在津巴布韦和莫桑比克，由心水病（反刍兽考德里氏体感染）导致的家畜损失，当传播媒介为希伯来花蜱时比为变异革蜱时更大。有人提出，该疾病的流行病学可能受这两种蜱虫未进食成虫附着到未感染宿主的速率影响（即，在没有雄性产生的聚集附着信息素[AAP]的情况下）。在本研究中，我们将未进食的希伯来花蜱和变异革蜱雄性置于未感染的牛、羊和兔子身上，并记录它们的附着率。两种蜱虫的雄性在牛身上附着得比在羊或兔子身上更快。希伯来花蜱的雄性在所有三种宿主物种上附着得都比变异革蜱的雄性更快。两种蜱虫在附着率上的差异在羊和兔子身上比在牛身上大得多。研究结果表明，在没有AAP的情况下，两种蜱虫的先锋雄性可能附着到牛身上，而希伯来花蜱的先锋雄性也可能附着到羊身上。希伯来花蜱和变异革蜱附着率的差异为观察到的与这两种传播媒介物种相关的心水病流行病学差异提供了一种可能的解释。
