Boyce W M, Zarnke R L
Department of Pathology, Microbiology, and Immunology, University of California, Davis 95616, USA.
J Wildl Dis. 1996 Oct;32(4):711-3. doi: 10.7589/0090-3558-32.4.711.
We determined that antibody responses to Psoroptes sp. mites were not present in 403 of 407 sera samples collected opportunistically from 1979 through 1991 from Dall sheep (Ovis dalli) from five locations in Alaska, USA (Eastern Arctic, n = 61; Central Arctic, n = 15; Western Interior, n = 122; Central Interior, n = 63; Eastern Interior, n = 146). Test values for four samples exceeded the positive cutoff value for the immunoassay, but exposure to mites could not be confirmed since the 95% confidence interval for true prevalence ranged from 0 to 2.3%. Therefore, we concluded that these were probably false positive results. Our analysis, coupled with the lack of previous reports of mites or lesions in Dall sheep or other Alaskan ungulates, provided indirect evidence that Psoroptes sp. are not enzootic in Dall sheep in Alaska. In contrast, Psoroptes sp. have been reported in bighorn sheep (Ovis canadensis) and other wild ungulate populations from southern Canada to Mexico. These findings are compatible with the hypothesis that Psoroptes sp. were introduced into North America with imported domestic sheep and were not introduced by ancestral wild sheep.
我们确定，1979年至1991年期间，在美国阿拉斯加五个地点（东北极地区，n = 61；中北极地区，n = 15；西部内陆，n = 122；中部内陆，n = 63；东部内陆，n = 146）从多尔大角羊（Ovis dalli）中随机采集的407份血清样本中，有403份对痒螨属螨虫没有抗体反应。四个样本的检测值超过了免疫测定的阳性临界值，但由于真实患病率的95%置信区间为0至2.3%，因此无法确认是否接触过螨虫。所以，我们得出结论，这些可能是假阳性结果。我们的分析，再加上之前没有关于多尔大角羊或其他阿拉斯加有蹄类动物身上有螨虫或病变的报告，间接证明了痒螨属螨虫在阿拉斯加的多尔大角羊中并非地方性流行。相比之下，在加拿大南部到墨西哥的大角羊（Ovis canadensis）和其他野生有蹄类动物种群中曾报告过痒螨属螨虫。这些发现与以下假设相符：痒螨属螨虫是随进口家养绵羊引入北美，而非由野生祖先绵羊引入。
