Structure and Genotypes of Noroviruses

Human noroviruses are structurally very simple, but how this correlates with their highly infectious nature, environmental stability, and the fact that they survive commonly used food sterilization processes remains elusive. Noroviruses are genetically very diverse, and new genogroups and genotypes are continuously being discovered. Some norovirus genotypes are more commonly found in foodborne outbreaks, suggesting that virological factors may determine virus adsorption characteristics to food surfaces and the efficiency of food-to-person transmission. Noroviruses can be found in a wide range of mammalian species, including pigs and cows that are extensively farmed for human consumption. The zoonotic potential of animal noroviruses via the food chain cannot be ignored.