Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853, USA.
Ecohealth. 2009 Dec;6(4):540-5. doi: 10.1007/s10393-009-0269-2. Epub 2010 Feb 4.
Because many pathogens can infect multiple host species within a community, disease dynamics in a focal host species can be affected by the composition of the host community. We examine the extent to which spatial variation in species' abundances in an avian host community may contribute to geographically varying prevalence of a recently emerged wildlife pathogen. Mycoplasma gallisepticum is a pathogen novel to songbirds that has caused substantial mortality in house finches (Carpodacus mexicanus) in eastern North America. Though the house finch is the primary host species for M. gallisepticum, the American goldfinch (Spinus tristis) and northern cardinal (Cardinalis cardinalis) are alternate hosts, and laboratory experiments have demonstrated M. gallisepticum transmission between house finches and goldfinches. Still unknown is the real world impact on disease dynamics of variation in abundances of the three hosts. We analyzed data from winter-long bird and disease surveys in the northeastern United States. We found that higher disease prevalence in house finches was associated with higher numbers of northern cardinals and American goldfinches, although only the effect of cardinal abundance was statistically significant. Nevertheless, our results indicate that spatial variation in bird communities has the potential to cause geographic variation in disease prevalence in house finches.
由于许多病原体可以感染同一群落中的多个宿主物种，因此宿主群落的组成会影响焦点宿主物种的疾病动态。我们研究了鸟类宿主群落中物种丰度的空间变化在多大程度上可能导致最近出现的野生动物病原体在地理上的流行程度不同。鸡毒支原体是一种新型的鸣禽病原体，在北美的东部地区已经导致了大量的家雀（Carpodacus mexicanus）死亡。尽管家雀是鸡毒支原体的主要宿主物种，但金翅雀（Spinus tristis）和红衣主教鸟（Cardinalis cardinalis）是替代宿主，实验室实验已经证明了家雀和金翅雀之间的鸡毒支原体传播。目前还不知道三种宿主丰度的变化对疾病动态的实际影响。我们分析了美国东北部冬季鸟类和疾病调查的数据。我们发现，家雀的疾病流行率较高与红衣主教鸟和金翅雀的数量较多有关，尽管只有红衣主教鸟数量的影响具有统计学意义。尽管如此，我们的结果表明，鸟类群落的空间变化有可能导致家雀疾病流行率在地理上的差异。
