{"title":"RHDV2 outbreak reduces survival and juvenile recruitment, causing European rabbit population collapse","authors":"Jérôme Letty, Aurélien Besnard, Nicolas Chatelain, Rémi Choquet, Gilles Holé, Yves Léonard, Régis Vannesson, Stéphane Marchandeau","doi":"10.1002/ecs2.70003","DOIUrl":null,"url":null,"abstract":"<p>Infectious diseases can cause considerable mortality in vertebrate populations, especially when a new pathogen emerges. Quantifying the impact of diseases on wild populations and dissecting the underlying mechanisms requires longitudinal individual monitoring combining demographic and epidemiologic data. Such longitudinal population studies are rare. Rabbit hemorrhagic disease (RHD) is one of the main causes of the decline in European wild rabbit (<i>Oryctolagus cuniculus</i>) populations. A new genotype of RHD virus (RHDV), called RHDV2 or GI.2, emerged in 2010, posing a new threat to previously weakened populations, particularly as this virus can infect individuals already immune to classical RHDV strains. Taking advantage of intensive monitoring from 2009 to 2014 by physical captures and microchip detections of a semi-captive population of rabbits, we finely assessed the demographic impact of an initial RHDV2 outbreak that occurred in the population and identified the most affected demographic parameters. A multi-event modeling analysis revealed decreased survival in both juveniles and adults in 2011 and 2012, suggesting an RHDV2 outbreak for two consecutive years. The short-term survival benefit of vaccination against classical RHDV strains only during these years, and the recovery of carcasses with RHDV2 detection, supported this hypothesis. Variations in population vaccination coverage also explain the difference in adult survival between the two years of the outbreak. And the transient protective effect of vaccination could explain the prolonged duration of the outbreak. A brief episode of myxomatosis in 2011 seems to have had only a limited impact on the population. During outbreak years, in individuals not recently vaccinated, monthly juvenile survival crashed (0.55), and annual adult survival was three times lower than in normal years (0.21 vs. 0.69). The combination of successive juvenile and adult survival estimates for unvaccinated rabbits during the outbreak years resulted in a very low recruitment rate in the breeding population. Finally, RHDV2 outbreaks appear to have caused mortalities comparable to those caused by older classical RHDV strains and may have a strong demographic impact on wild populations of European rabbit. This work highlights the importance of long-term observational and experimental studies to better understand the impact of epidemics on animal populations.</p>","PeriodicalId":48930,"journal":{"name":"Ecosphere","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.70003","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ecosphere","FirstCategoryId":"93","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/ecs2.70003","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Infectious diseases can cause considerable mortality in vertebrate populations, especially when a new pathogen emerges. Quantifying the impact of diseases on wild populations and dissecting the underlying mechanisms requires longitudinal individual monitoring combining demographic and epidemiologic data. Such longitudinal population studies are rare. Rabbit hemorrhagic disease (RHD) is one of the main causes of the decline in European wild rabbit (Oryctolagus cuniculus) populations. A new genotype of RHD virus (RHDV), called RHDV2 or GI.2, emerged in 2010, posing a new threat to previously weakened populations, particularly as this virus can infect individuals already immune to classical RHDV strains. Taking advantage of intensive monitoring from 2009 to 2014 by physical captures and microchip detections of a semi-captive population of rabbits, we finely assessed the demographic impact of an initial RHDV2 outbreak that occurred in the population and identified the most affected demographic parameters. A multi-event modeling analysis revealed decreased survival in both juveniles and adults in 2011 and 2012, suggesting an RHDV2 outbreak for two consecutive years. The short-term survival benefit of vaccination against classical RHDV strains only during these years, and the recovery of carcasses with RHDV2 detection, supported this hypothesis. Variations in population vaccination coverage also explain the difference in adult survival between the two years of the outbreak. And the transient protective effect of vaccination could explain the prolonged duration of the outbreak. A brief episode of myxomatosis in 2011 seems to have had only a limited impact on the population. During outbreak years, in individuals not recently vaccinated, monthly juvenile survival crashed (0.55), and annual adult survival was three times lower than in normal years (0.21 vs. 0.69). The combination of successive juvenile and adult survival estimates for unvaccinated rabbits during the outbreak years resulted in a very low recruitment rate in the breeding population. Finally, RHDV2 outbreaks appear to have caused mortalities comparable to those caused by older classical RHDV strains and may have a strong demographic impact on wild populations of European rabbit. This work highlights the importance of long-term observational and experimental studies to better understand the impact of epidemics on animal populations.
传染病会导致脊椎动物种群大量死亡,尤其是在新病原体出现时。要量化疾病对野生种群的影响并剖析其潜在机制,需要结合人口统计学和流行病学数据对个体进行纵向监测。这种纵向种群研究并不多见。兔出血性疾病(RHD)是欧洲野兔(Oryctolagus cuniculus)种群数量下降的主要原因之一。2010年出现了一种名为RHDV2或GI.2的出血性兔病病毒(RHDV)新基因型,对先前衰弱的种群构成了新的威胁,尤其是因为这种病毒可以感染已经对传统RHDV毒株免疫的个体。利用2009年至2014年期间对半圈养兔子种群的物理捕捉和芯片检测进行的密集监测,我们对种群中首次爆发的RHDV2疫情对人口的影响进行了精细评估,并确定了受影响最大的人口参数。多事件建模分析表明,2011年和2012年幼兔和成兔的存活率都有所下降,这表明RHDV2疫情已连续两年爆发。在这两年中,接种经典RHDV毒株疫苗可在短期内提高存活率,而且发现了检出RHDV2的尸体,这些都支持了这一假设。人群疫苗接种覆盖率的变化也解释了疫情爆发的两年中成人存活率的差异。疫苗接种的短暂保护作用可以解释疫情持续时间较长的原因。2011 年短暂爆发的肌瘤病似乎只对人群产生了有限的影响。在疫情爆发的年份,未接种疫苗的个体每月的幼体存活率下降(0.55),每年的成体存活率是正常年份的三倍(0.21 vs. 0.69)。在疫情爆发年份,未接种疫苗的兔子的幼兔和成兔存活率连续下降,导致繁殖种群的招募率非常低。最后,RHDV2疫情造成的死亡率似乎与较早的经典RHDV毒株造成的死亡率相当,可能会对欧洲兔的野生种群产生强烈的人口影响。这项工作强调了长期观察和实验研究的重要性,以便更好地了解流行病对动物种群的影响。
期刊介绍:
The scope of Ecosphere is as broad as the science of ecology itself. The journal welcomes submissions from all sub-disciplines of ecological science, as well as interdisciplinary studies relating to ecology. The journal''s goal is to provide a rapid-publication, online-only, open-access alternative to ESA''s other journals, while maintaining the rigorous standards of peer review for which ESA publications are renowned.