Dynamics of An Emerging Pathogen in an Introduced Host

近几十年来，出现了许多新的疾病。在某些情况下，现有的疾病有机体会跳到新的宿主上，有时会产生毁灭性的影响。1994年，一种新的鸡毒支原体(MG)菌株出现，并在北美东部的家雀中迅速传播。这导致家雀在2-3年内减少了1亿-2亿只，稳定在疾病前水平的40%。研究人员将继续监测整个大陆的MG流行情况和家雀数量，涉及大量志愿者；进行密集的实地工作，收集有关感染和未感染家雀的生态和行为信息；并进行受控鸟类实验，以测量MG在家雀中的传播率。重点将放在确定影响疾病传播和维持的与人类有关的因素。这些信息将用于开发和验证可应用于类似系统的一般预测模型。了解哪些因素导致新疾病的出现，哪些因素有利于新疾病的传播，以及它们如何影响宿主，对于控制新疾病至关重要。

In recent decades many new diseases have emerged. In some cases existing disease organisms jumped to novel hosts with sometimes devastating effects. In 1994 a new strain of Mycoplasma gallisepticum (MG), a bacterium common in poultry, appeared and spread very rapidly through the house finches of eastern North America. This caused house finches to decline within 2-3 years by 100-200 million birds, stabilizing at 40% of pre-disease levels. The researchers will continue to monitor MG prevalence and house finch abundance across the entire continent, involving large numbers of volunteers; carry out intensive fieldwork to gather information about the ecology and behavior of both infected and non-infected house finches; and perform controlled aviary experiments to measure the rate of transmission of MG among house finches. Emphasis will be placed on identifying human-related factors that modify the spread and maintenance of the disease. This information will be used to develop and validate general predictive models that can be applied to similar systems. Understanding which factors are responsible for the emergence of new diseases, which factors favor for their spread, and how they affect their hosts is essential to the control of new diseases.