Detection of norovirus in food samples collected during suspected food‐handler‐involved foodborne outbreaks in Tokyo

Abstract

Although norovirus (NoV) is the major cause of gastroenteritis, with the largest number of NoV food poisoning cases in Japan, limited information is available regarding NoV detection in food. This study aimed to detect NoV in food samples during the 2015–2016 suspected foodborne outbreaks in Tokyo; 352 food samples from 64 NoV food poisoning outbreaks were collected. Bacterial culturing was performed for sample pretreatment and real‐time reverse transcription polymerase chain reaction was conducted for NoV screening. The NoV detection rate was 1·7% (6/352). NoV‐positive food samples included leftover boxed lunch, mackerel fillet (foodstuff), aburi salmon slice (partially seared salmon slice), raw tuna as a chirashizushi ingredient, raw amberjack as a sushi topping and ice for drinks. Since fresh fish as sushi toppings or ingredients and ice were consumed without heating, they may present a higher risk of viral infection. NoV‐positive food samples were obtained from five outbreaks, wherein food handlers were NoV‐positive in four. Each partial VP1 sequence from food samples matched completely with those in NoV‐positive individuals and food handlers. Hence, food handlers play a potentially important role in food‐based NoV transmission in all five outbreaks; therefore, hygiene education among them is essential to prevent NoV foodborne outbreaks. Significance and Impact of the Study Significance and Impact of the Study: Norovirus (NoV) is a leading cause of foodborne outbreak in Japan. The most frequent route of transmission in NoV foodborne outbreaks is secondary contamination via infected food handlers. However, limited information is available regarding NoV contamination in food samples. This study reports the detection of NoV in food samples to elucidate the source and route of NoV infection leading to outbreaks for 2 years in Tokyo. Our data potentially contribute to education and the development of safe food‐handling strategies among food handlers and employees in the food industry through elucidation of risk factors associated with NoV contamination.

Real-time Sensing of Trace Biomarkers from Viruses with a Microfluidic Immunosensor: A Case Study of SARS-CoV-2 Detection in Cold-chain Food

“…More typical examples have been showing their destructive power, such as large outbreaks of hepatitis A [2,3] and norovirus infection. [4,5] As expected, these viruses are detected in various foods as well as waters, [1,6,7] which exacerbates the spread of the disease. Therefore, the viral contamination detection in food poses a more great challenge in recent decade.…”

Real-time Sensing of Trace Biomarkers from Viruses with a Microfluidic Immunosensor: A Case Study of SARS-CoV-2 Detection in Cold-chain Food

“…Another merit of this strategy is the high specificity. The selectivity for S-protein against the interference is calculated to be 6.02×10 5 : 1, which means that the response from non-target molecules is equal to that from the target when their concentration ratio reaches 10 5 . Not only common organic molecules, but also various matrices as backgrounds are verified to be nonresponsive, with known or unknown components.…”

“…Although viral epidemics are less reported for food safety compared with bacteria [1], their transmissibility is not weak at all. More typical examples have been showing their destructive power, such as large outbreaks of hepatitis A [2,3] and norovirus infection [4,5]. As expected, these viruses are detected in various foods as well as waters [1,6,7], which exacerbates the spread of the disease.…”

Assessment of the Microbiological Quality and Safety in Takeaway Sushi Meals in Portugal

“…The scientific literature indicates some outbreaks of foodborne diseases caused by sushi and sashimi. Salmonella strains are more frequently involved, but also enterotoxigenic Escherichia coli and the virus Norwalk have been found [7][8][9][10][11].…”