Saito Koichi, Sato Naoto, Takahashi Akemi, Tsutsumi Reiko, Sato Shigehiro
Department of Health Science, Research Institute for Environmental Science and Public Health of Iwate Prefecture.
Kansenshogaku Zasshi. 2006 Jul;80(4):399-404. doi: 10.11150/kansenshogakuzasshi1970.80.399.
Noroviruses (NVs) cause human gastroenteritis through person-to-person transmission and via contaminated foods. In food poisoning, a major suspected cause is the consumption of raw oysters. We detected NVs from environmental water and oysters around a closed gulf where oysters are cultivated. We collected oyster and water samples once or twice a month for 30 months from October 2001 to March 2004. We then studied monthly changes in virus occurrence and in genetic relationships among 208 NVs isolated from water and oyster samples and from the feces of children suffering from acute gastroenteritis during the same period in the same region. In the analysis of untreated water flowing into farm sewage, NVs were detected year round. In other water samples -processed sewage, river water, and seawater-, oysters, and children's feces, NVs were detected mainly in winter. A comparison of NV nucleotide sequences showed genetic diversity, but some strains predominated in certain winter seasons. These predominant strains were detected across sample materials. In 2002/03, an identical strain was detected in sewage, river water, seawater, oysters, and feces. We also found that NV genetic types changed at the beginning of the season, in November or December, in both 2001/02 and 2002/03. This study showed a clear relationship between NVs detected in children's feces and those in environmental water and oysters. These results support the idea that NVs are transmitted from the feces of infected persons to oysters by the flow of water through farm sewage, rivers, and the sea, finally accumulating in the mid-gut gland of oysters.
诺如病毒（NVs）通过人际传播和受污染食物导致人类肠胃炎。在食物中毒事件中，一个主要的可疑原因是食用生牡蛎。我们在一个封闭海湾周围的环境水和牡蛎中检测到了诺如病毒，该海湾是牡蛎养殖地。从2001年10月至2004年3月，我们每月采集一次或两次牡蛎和水样，持续30个月。然后，我们研究了同期在同一地区从水样、牡蛎样本以及患有急性肠胃炎儿童的粪便中分离出的208株诺如病毒的病毒发生率月度变化和基因关系。在对流入养殖场污水的未处理水中，全年都检测到了诺如病毒。在其他水样——处理后的污水、河水和海水中——以及牡蛎和儿童粪便中，诺如病毒主要在冬季被检测到。诺如病毒核苷酸序列的比较显示出基因多样性，但某些毒株在特定冬季占主导地位。这些优势毒株在不同样本材料中均被检测到。在2002/03年，在污水、河水、海水、牡蛎和粪便中检测到了相同的毒株。我们还发现，在2001/02年和2002/03年，诺如病毒基因类型在季节开始时，即11月或12月发生了变化。这项研究表明，在儿童粪便中检测到的诺如病毒与环境水和牡蛎中的诺如病毒之间存在明显的关系。这些结果支持了这样一种观点，即诺如病毒通过水流经养殖场污水、河流和海洋，从感染者的粪便传播到牡蛎，最终在牡蛎的中肠腺中积累。
