Gómez Andrés, Kramer Laura D, Dupuis Alan P, Kilpatrick A Marm, Davis Lauren J, Jones Matthew J, Daszak Peter, Aguirre A Alonso
Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA.
Am J Trop Med Hyg. 2008 Sep;79(3):447-51.
Eastern gray squirrels (Sciurus carolinensis) have shown high West Nile virus (WNV) seroprevalence, and WNV infection has been suggested as a cause of morbidity and mortality in this species. We experimentally infected nine eastern gray squirrels with WNV to determine the clinical effects of infection and to assess their potential role as amplifying hosts. We observed no morbidity or mortality attributable to WNV infection, but lesions were apparent in several organs. We detected mean viremias of 10(5.1) and 10(4.8) plaque-forming units (PFU)/mL on days 3 and 4 post-infection (DPI) and estimated that approximately 2.1% of Culex pipiens feeding on squirrels during 1-5 DPI would become infectious. Thus, S. carolinensis are unlikely to be important amplifying hosts and may instead dampen the intensity of transmission in most host communities. The low viremias and lack of mortality observed in S. carolinensis suggest that they may be useful as sentinels of spillover from the enzootic amplification cycle.
东部灰松鼠（Sciurus carolinensis）的西尼罗河病毒（WNV）血清阳性率很高，WNV感染被认为是该物种发病和死亡的一个原因。我们用WNV对9只东部灰松鼠进行了实验性感染，以确定感染的临床影响，并评估它们作为扩增宿主的潜在作用。我们未观察到由WNV感染引起的发病或死亡情况，但在几个器官中出现了病变。在感染后第3天（DPI）和第4天，我们检测到平均病毒血症分别为10(5.1)和10(4.8) 空斑形成单位（PFU）/毫升，并估计在感染后1 - 5天内以松鼠为食的淡色库蚊中约2.1%会具有传染性。因此，东部灰松鼠不太可能是重要的扩增宿主，反而可能会降低大多数宿主群落中的传播强度。在东部灰松鼠中观察到的低病毒血症和无死亡情况表明，它们可能作为动物疫病流行扩增循环中溢出的哨兵很有用。
