Degree of host susceptibility in the initial disease outbreak influences subsequent epidemic spread.
Degree of host susceptibility in the initial disease outbreak influences subsequent epidemic spread.
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疾病暴发初期宿主的易感程度影响随后的疫情传播。
DOI：
10.1111/1365-2664.12326
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Mundt,ChristopherC
中科院分区：
文献类型：
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作者：
Severns,PaulM;Estep,LauraK;Sackett,KathrynE;Mundt,ChristopherC
疾病流行通常始于相对较小的、空间明确的受感染个体群体（焦点）的爆发，其中疾病流行率增加并迅速传播到未受感染的高危人群中。流行病传播的研究通常涉及影响疾病在高危人群中传播的因素，但最初的爆发可能会强烈影响随后流行病的传播。我们发起了小麦条锈病Puccinia striiformisf。 当重点人群和重点人群之间的疾病易感性程度不同时，使用 sp.triticiepidemics 来评估重点对最终疾病流行率的影响。当重点/高危种植品种由部分遗传抗性和易感品种组成时，最终疾病流行率与单一栽培中重点品种产生的流行病在统计上无法区分。在这些实验性流行病中，疾病患病率并未受到疾病易感性不同的高危人群转变的影响。相反，焦点似乎对随后的流行病产生了主导影响。当焦点/高危人群与混合（约28％易感和72％耐药）和易感个体混合的因子设置中时，最终疾病患病率并不总是归因于焦点或高危人群。在这些实验流行病中，高危人群内疾病易感性的空间异质性似乎抵消了病灶的主导影响。条锈病传播1·3代后，病灶停止产生孢子（通过使用杀菌剂/草甘膦）并没有降低最终的疾病流行率，这表明病灶对疾病传播的影响在流行早期就已确立。合成和应用。我们的实验表明，即使高危人群的抗病能力强于重点人群，暴发条件也可能对流行病的传播产生很大影响。在疫源地首次爆发后不久进行的疾病控制治疗可以防止流行病的发生或减轻其严重程度。
Disease epidemics typically begin as an outbreak of a relatively small, spatially explicit population of infected individuals (focus), in which disease prevalence increases and rapidly spreads into the uninfected, at‐risk population. Studies of epidemic spread typically address factors influencing disease spread through the at‐risk population, but the initial outbreak may strongly influence spread of the subsequent epidemic.We initiated wheat stripe rustPuccinia striiformisf. sp.triticiepidemics to assess the influence of the focus on final disease prevalence when the degree of disease susceptibility differed between the at‐risk and focus populations.When the focus/at‐risk plantings consisted of partially genetic resistant and susceptible cultivars, final disease prevalence was statistically indistinguishable from epidemics produced by the focus cultivar in monoculture. In these experimental epidemics, disease prevalence was not influenced by the transition into an at‐risk population that differed in disease susceptibility. Instead, the focus appeared to exert a dominant influence on the subsequent epidemic.Final disease prevalence was not consistently attributable to either the focus or the at‐risk population when focus/at‐risk populations were planted in a factorial set‐up with a mixture (c. 28% susceptible and 72% resistant) and susceptible individuals. In these experimental epidemics, spatial heterogeneity in disease susceptibility within the at‐risk population appeared to counter the dominant influence of the focus.Cessation of spore production from the focus (through fungicide/glyphosate application) after 1·3 generations of stripe rust spread did not reduce final disease prevalence, indicating that the focus influence on disease spread is established early in the epidemic.Synthesis and applications. Our experiments indicated that outbreak conditions can be highly influential on epidemic spread, even when disease resistance in the at‐risk population is greater than that of the focus. Disease control treatments administered shortly after the initial outbreak within the focus may either prevent an epidemic from occurring or reduce its severity.