University of Torino, Grugliasco, Italy.
FEMS Microbiol Rev. 2012 Jul;36(4):837-61. doi: 10.1111/j.1574-6976.2011.00312.x. Epub 2011 Dec 28.
The analysis of different multi-host systems suggests that even hosts that are not capable of transmitting Borrelia burgdorferi sensu lato (s.l.) to the tick vector, Ixodes ricinus, or that are secondary reservoirs for these agents contribute to the intensity of transmission and to the overall risk of Lyme borreliosis, through the process of vector augmentation and pathogen amplification. On the other hand, above certain threshold densities, or in the presence of competition with primary reservoir hosts or low attachment rate of ticks to reservoir hosts, incompetent or less competent hosts may reduce transmission through dilution. The transmission of B. burgdorferi s.l. is affected by molecular processes at the tick-host interface including mechanisms for the protection of spirochaetes against the host's immune response. Molecular biology also increasingly provides important identification tools for the study of tick-borne disease agents. Ixodes ricinus and B. burgdorferi s.l. are expanding their geographical range to northern latitudes and to higher altitudes through the effects of climate change on host populations and on tick development, survival and seasonal activity. The integration of quantitative ecology with molecular methodology is central to a better understanding of the factors that determine the main components of Lyme borreliosis eco-epidemiology and should result in more accurate predictions of the effects of climate change on the circulation of pathogens in nature.
对不同多宿主系统的分析表明，即使宿主不能将伯氏疏螺旋体（s.l.）传播给蜱虫媒介（蓖麻蜱），或者是这些病原体的次级储存宿主，它们也通过增强媒介和病原体放大的过程，有助于传播的强度和莱姆病的总体风险。另一方面，在超过一定的密度阈值，或者在与主要储存宿主竞争或蜱虫对储存宿主的附着率较低的情况下，无能力或能力较低的宿主可能通过稀释来降低传播。伯氏疏螺旋体（s.l.）的传播受到蜱虫-宿主界面的分子过程的影响，包括螺旋体对宿主免疫反应的保护机制。分子生物学也越来越为研究蜱传疾病病原体提供了重要的识别工具。蓖麻蜱和伯氏疏螺旋体（s.l.）通过宿主种群和蜱虫发育、生存和季节性活动对气候变化的影响，正在向高纬度和高海拔地区扩大其地理范围。将定量生态学与分子方法学相结合，对于更好地理解决定莱姆病生态流行病学主要因素至关重要，并且应该能够更准确地预测气候变化对病原体在自然界中循环的影响。
