Page L Kristen, Gehrt Stanley D, Cascione Andrea, Kellner Kenneth F
Biology Department, Wheaton College, Wheaton, Illinois 60187, USA.
J Parasitol. 2009 Dec;95(6):1314-20. doi: 10.1645/GE-1998.1.
Parasite transmission is a dynamic process that can be affected by factors including host and parasite population dynamics. Raccoons ( Procyon lotor ) are the definitive host of Baylisascaris procyonis , an intestinal roundworm. Transmission of this parasite has been linked to raccoon behavior and human land-use patterns; however, we do not know the importance of host population structure. Therefore, the objective of this study was to determine the relationship between raccoon population attributes and prevalence of B. procyonis. We necropsied 307 trapped or road-killed raccoons collected during 2000-2006 from the Chicago area. In addition, we examined, via fecal samples (n = 433), the patterns of B. procyonis prevalence as they relate to population dynamics among 3 subpopulations within the larger study. Baylisascaris procyonis was seen in 39% of 307 necropsied raccoons. There were differences in prevalence as a function of host age and sex. Baylisascaris procyonis was observed in 18% of 433 fecal samples obtained from live-trapped raccoons, and there were differences according to age, but not by sex. We found that the host populations consistently differed in density across study areas, but were similar regarding sex and age structure. Differences in host density were associated with differences in prevalence, suggesting that possible differences between populations, as well as ecological differences in sites and raccoon behavior, may have influenced parasite prevalence.
寄生虫传播是一个动态过程，会受到包括宿主和寄生虫种群动态等因素的影响。浣熊（北美浣熊）是犬弓首蛔虫（一种肠道蛔虫）的终末宿主。这种寄生虫的传播与浣熊行为和人类土地利用模式有关；然而，我们并不清楚宿主种群结构的重要性。因此，本研究的目的是确定浣熊种群属性与犬弓首蛔虫感染率之间的关系。我们对2000年至2006年期间从芝加哥地区捕获或道路致死的307只浣熊进行了尸检。此外，我们通过粪便样本（n = 433）研究了犬弓首蛔虫感染率模式与更大研究范围内3个亚种群的种群动态之间的关系。在307只接受尸检的浣熊中，39%发现有犬弓首蛔虫。感染率因宿主年龄和性别而异。从活体捕获的浣熊获得的433份粪便样本中，18%检测到犬弓首蛔虫，且感染率因年龄而异，但与性别无关。我们发现，不同研究区域的宿主种群密度始终存在差异，但在性别和年龄结构方面相似。宿主密度的差异与感染率的差异相关，这表明种群之间可能存在的差异以及地点和浣熊行为的生态差异可能影响了寄生虫感染率。
