Bianchi T I, Aviles G, Monath T P, Sabattini M S
Institute of Virology, Faculty of Medical Science, National University of Cordoba, Argentina.
Am J Trop Med Hyg. 1993 Sep;49(3):322-8. doi: 10.4269/ajtmh.1993.49.322.
Comparative studies are described on the virulence of the western equine encephalomyelitis (WEE) complex viruses for mice. Three epizootic WEE virus strains (McMillan, Cba 87, and Cba CIV 180) and five enzootic WEE complex viruses (Highlands J [HJ], Y62-33, Aura, Fort Morgan [FM], and WEE AG80-646) were examined. The neurovirulence and the neuroinvasiveness of these viruses for adult mice were established and correlated with viremia and virus replication in brain tissue. Adult mice inoculated intraperitoneally showed differential responses that corresponded to the epidemiologic attributes of WEE viruses. Viruses associated with equine epizootics were neurovirulent and neuroinvasive, whereas enzootic viruses were neither neuroinvasive nor neurovirulent. In North America, HJ virus appears to be an antigenic link with an intermediate virulence between epizootic WEE virus and the enzootic FM virus. The HJ virus has been associated with rare cases of sporadic equine and human diseases. In South America, no virus with intermediate virulence characteristics has been described. We speculate that epizootics may arise from nonpathogenic strains such as AG80-646 maintained in enzootic transmission cycles.
对西部马脑炎（WEE）复合病毒对小鼠的毒力进行了比较研究。检测了三株流行性WEE病毒（麦克米伦株、Cba 87株和Cba CIV 180株）和五株地方性WEE复合病毒（高地J株[HJ]、Y62 - 33株、奥拉株、摩根堡株[FM]和WEE AG80 - 646株）。确定了这些病毒对成年小鼠的神经毒力和神经侵袭力，并将其与病毒血症及脑组织中的病毒复制情况相关联。经腹腔接种的成年小鼠表现出与WEE病毒流行病学特征相对应的不同反应。与马流行性疾病相关的病毒具有神经毒力和神经侵袭力，而地方性病毒既无神经侵袭力也无神经毒力。在北美，HJ病毒似乎是一种抗原联系，其毒力介于流行性WEE病毒和地方性FM病毒之间。HJ病毒与罕见的散发性马和人类疾病病例有关。在南美，尚未描述具有中等毒力特征的病毒。我们推测，流行性疾病可能源自地方性传播循环中维持的非致病性毒株，如AG80 - 646株。
