Cheng Peter K C, Wong Derek K K, Chung Thomas W H, Lim Wilina W L
Virology Division, Public Health Laboratory Centre, Shek Kip Mei, Kowloon, Hong Kong.
J Med Virol. 2005 Aug;76(4):593-7. doi: 10.1002/jmv.20402.
Noroviruses (Norwalk-like viruses) are recognized as major causes of acute gastroenteritis worldwide. Outbreaks of norovirus gastroenteritis are often associated with consumption of oysters. In this study, oysters imported into Hong Kong from 11 countries over a 3-year period were screened by RT-PCR. Overall, 53 out of 507 (10.5%) samples were positive for norovirus-RNA, and a wide variety of strains were found. Two novel genetic clusters were detected, which could indicate novel human or animal norovirus strains. However, whether these two new clusters are of human or animal origin is not known. Thirteen outbreaks, in which oysters were implicated as the source of infection were investigated: Norovirus RNA sequences could be detected in oysters from six outbreaks, but only in one outbreak the strains isolated from patients and oysters matched (>98% homology). Therefore, RT-PCR was of use in detecting norovirus contamination of oysters implicated in an outbreak, but was less useful in demonstrating an actual molecular epidemiological link with human cases. It was shown that contamination by noroviruses could be demonstrated in oysters worldwide, and therefore oysters may serve as an important vehicle for introducing novel norovirus strains.
诺如病毒（诺沃克样病毒）被认为是全球急性胃肠炎的主要病因。诺如病毒胃肠炎的暴发通常与食用牡蛎有关。在本研究中，对3年期间从11个国家进口到香港的牡蛎进行了逆转录聚合酶链反应（RT-PCR）筛查。总体而言，507个样本中有53个（10.5%）诺如病毒RNA呈阳性，并且发现了多种毒株。检测到两个新的基因簇，这可能表明存在新的人类或动物诺如病毒毒株。然而，这两个新基因簇是人类还是动物来源尚不清楚。对13起涉及牡蛎为感染源的疫情进行了调查：在6起疫情的牡蛎中可检测到诺如病毒RNA序列，但只有1起疫情中从患者和牡蛎中分离出的毒株匹配（同源性>98%）。因此，RT-PCR可用于检测与疫情相关的牡蛎中的诺如病毒污染，但在证明与人类病例的实际分子流行病学联系方面作用较小。结果表明，全球范围内的牡蛎中均可检测到诺如病毒污染，因此牡蛎可能是引入新型诺如病毒毒株的重要载体。
