Rodhain F
Bull Soc Pathol Exot. 1998;91(4):279-82.
Aboviruses usually have extremely complex epidemiological cycles since their circulation involves successively a susceptible vertebrate and an hematophagous arthropod acting as vector. Natural reservoirs for arboviruses can belong to two different categories of organisms: Vertebrate reservoirs, with as main characteristics: a susceptible population but showing no symptoms of disease or only a benign one, an abundant and prolific population, the infected animal must show an efficient viremia, a population with strong and frequent contacts with vector populations. Two factors tend to oppose these characteristics: the pathogenicity of the virus and infection-induced immunity. Many groups of wild vertebrates (birds and mammals) act as usual reservoirs for arboviruses. Domestic or commensal mammals, as well as human beings, are rarely involved as reservoirs. Invertebrate reservoirs: arthropods are involved in the maintenance of many arboviruses for two main reasons: their longevity and the possibility of vertical transmission of the virus. An infected arthropod remains infected throughout its life, in spite of successive moultings. This lifetime can be long, especially for ticks. Vertical transmission is known in some virus-vector systems, but its frequency appears to be very variable. The epidemiological importance of the phenomenon is specially high in the case of cold-resistant or dry-resistant eggs. These facts lead to a large variety of epidemiological situations according to virus and region. Studying epidemiological situations also shows up the evolution of these systems, as a response to environmental modifications, often resulting from human activities. Furthermore, the repeated passages of an arbovirus in reservoir hosts could induce modifications of the viral genome, for example by facilitating the emergence of reassortants during coinfections. Finally, for many different reasons, it seems difficult, for the moment, to imagine efficient preventive measures levelled at any kind of natural reservoirs.
虫媒病毒通常具有极其复杂的流行病学循环，因为它们的传播过程依次涉及作为宿主的易感脊椎动物和作为媒介的吸血节肢动物。虫媒病毒的自然宿主可分为两类不同的生物体：脊椎动物宿主，其主要特征为：有易感种群，但不表现出疾病症状或仅表现为良性症状；种群数量丰富且繁殖力强；受感染动物必须出现有效的病毒血症；与媒介种群有频繁且密切的接触。有两个因素往往与这些特征相悖：病毒的致病性和感染诱导的免疫力。许多野生脊椎动物群体（鸟类和哺乳动物）通常作为虫媒病毒的宿主。家养或共生哺乳动物以及人类很少作为宿主参与其中。无脊椎动物宿主：节肢动物参与多种虫媒病毒的维持主要有两个原因：它们的寿命以及病毒垂直传播的可能性。受感染的节肢动物在其一生中都保持感染状态，尽管会经历多次蜕皮。这种寿命可能很长，尤其是蜱类。在一些病毒 - 媒介系统中已知存在垂直传播，但其频率似乎变化很大。在耐寒或耐旱卵的情况下，这一现象的流行病学重要性特别高。根据病毒和地区的不同，这些事实导致了各种各样的流行病学情况。研究流行病学情况还揭示了这些系统的演变，这是对环境变化的一种反应，而环境变化往往是由人类活动引起的。此外，虫媒病毒在宿主中的多次传播可能会导致病毒基因组的改变，例如通过在共感染期间促进重配体的出现。最后，由于许多不同的原因，目前似乎很难想象针对任何一种自然宿主采取有效的预防措施。
