Oakgrove Khouanchy S, Harrigan Ryan J, Loiseau Claire, Guers Sue, Seppi Bruce, Sehgal Ravinder N M
Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA.
Int J Parasitol. 2014 Sep;44(10):717-27. doi: 10.1016/j.ijpara.2014.04.011. Epub 2014 Jul 9.
Avian species are commonly infected by multiple parasites, however few studies have investigated the environmental determinants of the prevalence of co-infection over a large scale. Here we believe that we report the first, detailed ecological study of the prevalence, diversity and co-infections of four avian blood-borne parasite genera: Plasmodium spp., Haemoproteus spp., Leucocytozoon spp. and Trypanosoma spp. We collected blood samples from 47 resident and migratory bird species across a latitudinal gradient in Alaska. From the patterns observed at collection sites, random forest models were used to provide evidence of associations between bioclimatic conditions and the prevalence of parasite co-infection distribution. Molecular screening revealed a higher prevalence of haematozoa (53%) in Alaska than previously reported. Leucocytozoons had the highest diversity, prevalence and prevalence of co-infection. Leucocytozoon prevalence (35%) positively correlated with Trypanosoma prevalence (11%), negatively correlated with Haemoproteus prevalence (14%) and had no correlation with Plasmodium prevalence (7%). We found temperature, precipitation and tree cover to be the primary environmental drivers that show a relationship with the prevalence of co-infection. The results provide insight into the impacts of bioclimatic drivers on parasite ecology and intra-host interactions, and have implications for the study of infectious diseases in rapidly changing environments.
鸟类通常会感染多种寄生虫，然而很少有研究在大尺度上调查共感染流行率的环境决定因素。在此，我们认为我们首次报告了对四种鸟类血源寄生虫属（疟原虫属、血变原虫属、白细胞虫属和锥虫属）的流行率、多样性和共感染情况进行的详细生态学研究。我们在阿拉斯加沿纬度梯度采集了47种留鸟和候鸟的血样。根据在采集地点观察到的模式，使用随机森林模型来证明生物气候条件与寄生虫共感染分布流行率之间的关联。分子筛查显示，阿拉斯加血内寄生虫的流行率（53%）高于此前报告。白细胞虫的多样性、流行率和共感染流行率最高。白细胞虫的流行率（35%）与锥虫的流行率（11%）呈正相关，与血变原虫的流行率（14%）呈负相关，与疟原虫的流行率（7%）无相关性。我们发现温度、降水和树木覆盖是与共感染流行率呈现关联的主要环境驱动因素。这些结果为生物气候驱动因素对寄生虫生态学和宿主体内相互作用的影响提供了见解，并对快速变化环境中的传染病研究具有启示意义。
