Peter T F, Perry B D, O'Callaghan C J, Medley G F, Shumba W, Madzima W, Burridge M J, Mahan S M
University of Florida, USAID/SADC Heartwater Research Project, Harare, Zimbabwe.
Exp Appl Acarol. 1998 Dec;22(12):725-40. doi: 10.1023/a:1006045508522.
The tick vectors of heartwater (Cowdria ruminantium infection) in Zimbabwe, Amblyomma hebraeum and Amblyomma variegatum, historically were believed to be confined to the low-lying regions of the south and north-west of the country. However, country-wide surveys performed in 1975-1980 and 1988-1991 demonstrated that both species were also established in western parts of the highveld plateau and had started to encroach on the predominantly heartwater-free central and eastern highveld regions. To determine the current distributions of both the vectors and evaluate the potential threat of heartwater to animals in the highveld, a survey of ticks infesting cattle was performed in 1996 at 2994 locations in small-holder and large-scale commercial farming areas throughout Zimbabwe. Amblyomma hebraeum was collected at 1329 locations, A. variegatum at 72 locations and both A. hebraeum and A. variegatum at 13 locations. The results demonstrated that A. hebraeum was present, as previously recorded, throughout the southern half of the country and appeared to have undergone further limited spread into the central and eastern highveld regions. Only the northern-most region of the country appeared to be free of this species. Amblyomma variegatum was collected mainly in the north-west, as previously recorded, but was also found at isolated locations across the central highveld region and along the eastern border with Mozambique. This species was, however, still absent from the southern half and the northern-most regions of the country. An overlap of the distributions of the two species existed within a zone along the southern and eastern regions of the distribution of A. variegatum. These results suggest that the vectors of heartwater are spreading and threaten to introduce heartwater into intensive livestock-producing regions of the country.
在津巴布韦，心水病（反刍兽考德里氏体感染）的蜱虫传播媒介，即南非牛蜱和变异革蜱，在历史上被认为仅分布于该国南部和西北部的低洼地区。然而，在1975 - 1980年以及1988 - 1991年进行的全国性调查表明，这两个物种在高原高地西部也已定居，并开始侵入原本基本没有心水病的中部和东部高原高地地区。为了确定这两种传播媒介目前的分布情况，并评估心水病对高原高地地区动物的潜在威胁，1996年在津巴布韦各地的小农户和大规模商业养殖区的2994个地点对寄生在牛身上的蜱虫进行了调查。在1329个地点采集到了南非牛蜱，在72个地点采集到了变异革蜱，在13个地点同时采集到了南非牛蜱和变异革蜱。结果表明，如之前所记录的，南非牛蜱分布于该国南半部，并似乎已进一步有限度地扩散到中部和东部高原高地地区。该国最北部地区似乎没有这种物种。变异革蜱主要如之前所记录的那样采集于西北部，但在中部高原高地地区的一些孤立地点以及与莫桑比克接壤的东部边境沿线也有发现。然而，该国南半部和最北部地区仍然没有这种物种。在变异革蜱分布的南部和东部区域的一个地带内，这两个物种的分布存在重叠。这些结果表明，心水病的传播媒介正在扩散，并有可能将心水病引入该国集约化畜牧生产地区。
