Comparative ecological study of hantavirus in rodents in Japan and Far East Russia

在日本和俄罗斯远东地区进行了流行病学调查，结果如下：在受感染大鼠的尿液中鉴定出汉坦病毒。由于经鼻内接种含病毒尿液的新生大鼠在其器官和尿液中存在病毒，因此病毒在本质上可能是通过病毒污染的尿液经鼻内途径传播的。建立了以杆状病毒表达的不同汉坦病毒核衣壳蛋白为抗原的酶联免疫吸附试验（ELISA）。该方法不仅可以检测汉坦病毒抗体，还可以在血清与不同抗原反应时鉴定感染汉坦病毒的类型。为评价汉坦病毒肺综合征（HPS）患者的病毒载量，建立了定量PCR体系。结果表明，急性HPS患者血液中检测到大量病毒，但在恢复期血液中病毒消失。采用多种血清学方法在日本开展了大规模汉坦病毒流行病学研究。在健康成人中，没有人有汉坦病毒抗体，而在病因不明的肝病患者中，有2 - 3%的病例有抗体。因此，毫无疑问，日本的普通民众都感染了汉坦病毒。在俄罗斯远东符拉迪沃斯托克开展了汉坦病毒靶向啮齿动物的流行病学研究。在日本北海道已知的普玛拉型汉坦病毒储存地灰背田鼠（Clethrionomys rufocanus）中检测到汉坦病毒抗体。由于中国和韩国汉坦型汉坦病毒的宿主剥地鼠（黑线鼠）也有抗体，因此高毒株可能在俄罗斯远东地区流行。此外，在芦苇田鼠（Microtis fortis）中鉴定出汉坦病毒基因组，序列分析显示该病毒与其他已知的汉坦病毒不同。

Epidemiological study was conducted in Japan and Far East Russia and the followings were revealed.1. Hantavirus was identified in the urine from infected rats. Since newborn rats intranasally inoculated with the urine containing virus had the virus in their organs and urine, the virus may be maintained by the transmission with virus-contaminated urine by intranasal route in nature.2. Enzyme linked immunosorbent assay (ELISA) using baculovirus-expressed nucleocapsid proteins of different hantaviruses as antigens was established. This assay made it possible to detect hantaviral antibody and also identify the type of infected hantavirus when sera were reacted with different antigens.3. To evaluate the virus load in patients of hantavirus pulmonary syndrome (HPS), quantitative PCR system was established. According this PCR, it was revealed that high amount of virus was detectable in blood of acute HPS patients but the virus was disappeared form blood in convalescent phase.4. Large scale of epidemiological study of hantavirus was conducted in Japan by using severa serological methods. In healthy adults, no one had hantaviral antibody while in hepatic disease patients of unknown etiology, 2 to 3 % of cases had the antibodies. Therefore, it is no doubt that the general public in Japan have hantavirus infections.5. Epizootiologic study of hantavirus targeting for rodents was carried out in Vladivostok, Far East Russia. Hantaviral antibody was detected in gray-backed vole (Clethrionomys rufocanus), hich is known to be a reservoir of Puumala type hantavirus in Hokkaido, Japan. Since stripped field mice (Apodemus agrarius), which is a reservoir of Hantaan type hantavirus in China and Korea, also had the antibodies, highly virulent strain may be prevalent in Far Eastern Russia. In addition, hantavirus genome was identified in reed vole (Microtis fortis) and sequence analysis revealed that this virus was distinct from other known hantaviruses.