Nemeth Nicole, Young Ginger, Ndaluka Christina, Bielefeldt-Ohmann Helle, Komar Nicholas, Bowen Richard
National Wildlife Research Center, 4101 Laporte Avenue, Fort Collins, CO 80521, USA.
Arch Virol. 2009;154(5):783-9. doi: 10.1007/s00705-009-0369-x. Epub 2009 Apr 4.
Long-term persistence of West Nile virus (WNV) infection within vertebrate reservoir hosts is a potential mechanism for overwintering of this (and other) arbovirus(es) at temperate latitudes. The house sparrow (Passer domesticus), an established amplifying host for WNV and other arboviruses, was used as a model to confirm chronicity of WNV infection in passerine birds and to evaluate the feasibility of two overwintering mechanisms: blood-borne infection of arthropod vectors (recrudescence) and oral infection of vertebrate reservoir hosts (ingestion of infected tissues through predation). WNV-inoculated sparrows were monitored for persistent infection for up to 2 years. Infectious virus persisted in tissues through 43 days, but not in sera beyond 6 days. Viral RNA persisted in tissues through 65 days. Chronicity of WNV infection in some tissues, but not blood, supports the predation mechanism of WNV overwintering, but not recrudescence. RNA persistence impacts interpretation and etiologic determination of avian mortality.
西尼罗河病毒（WNV）在脊椎动物储存宿主内的长期持续感染是该（及其他）虫媒病毒在温带地区越冬的一种潜在机制。家麻雀（Passer domesticus）是WNV和其他虫媒病毒已确定的扩增宿主，被用作模型来确认雀形目鸟类中WNV感染的慢性情况，并评估两种越冬机制的可行性：节肢动物媒介的血源性感染（复发）和脊椎动物储存宿主的经口感染（通过捕食摄入受感染组织）。对接种WNV的麻雀进行了长达2年的持续感染监测。感染性病毒在组织中持续存在43天，但在血清中超过6天后就不再存在。病毒RNA在组织中持续存在65天。WNV在某些组织而非血液中的慢性感染支持了WNV越冬的捕食机制，但不支持复发机制。RNA的持续存在影响对禽类死亡的解释和病因判定。
