Multiple norovirus outbreaks linked to imported frozen raspberries

Abstract

In 2009, the number of foodborne norovirus outbreaks in Finland seemed markedly high, and many outbreaks seemed to be linked to imported frozen raspberries. We reviewed the data regarding all notified foodborne outbreaks in 2009 in Finland in order to assess the magnitude of the problem and to summarize the information on raspberry-linked outbreaks. Between March and August, 13 norovirus outbreaks affecting about 900 people could be linked to imported frozen raspberries. Two raspberry samples corresponding to two batches of raspberries were positive for norovirus. These two batches proved to have been the likely source in six of the 13 outbreaks. Analytical studies had not been conducted for six outbreaks, and virological test results were inconclusive in two. However, combining epidemiological and microbiological methods often enabled finding the source, as exemplified in investigation of a large school outbreak. To ensure prompt control measures in similar situations in the future, both aspects of outbreak investigations should be strengthened.

Evidence of the Internalization of Animal Caliciviruses via the Roots of Growing Strawberry Plants and Dissemination to the Fruit

“…Several human NoV outbreaks have been associated with the consumption of soft berries, many of which could be linked to the use of irrigation water sources contaminated with sewage (10,11,13,14). The fresh produce market is global, and in many outbreaks, the product is imported from countries that have their own production practices and food safety management systems, which may not regulate irrigation water sources (31).…”

“…Human NoV alone accounts for over 40% of the fresh produce-related illnesses reported each year in the United States (1,2,(4)(5)(6)(7)(8). Human NoV has been attributed to outbreaks in many diverse types of produce, including fresh cut fruit, lettuce, tomatoes, melons, salads, green onions, strawberries, blueberries, raspberries, and salsa, as well as many others (5)(6)(7)(9)(10)(11)(12)(13)(14)(15). Human NoV is resistant to common disinfectants, has a low infectious dose, and is highly stable in the environment, which contributes to the high prevalence of foodborne outbreaks associated with the virus and its presence and persistence in food commodities (3,16,17).…”

Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce

“…Human NoV alone accounts for more than 40% of the freshproduce-related illnesses reported each year in the United States (1,2,4,(6)(7)(8)(9). Outbreaks in many diverse types of produce, including fresh cut fruit, lettuce, tomatoes, melons, salads, green onions, strawberries, blueberries, raspberries, and salsa, have been attributed to human NoV (6,7,(10)(11)(12)(13)(14)(15). Human NoV is highly infectious, is resistant to common disinfectants, has a low infectious dose, and is highly stable in the environment, all features that contribute to the high prevalence of food-borne outbreaks associated with the virus and its presence and persistence in food commodities (3,5,7,(16)(17)(18)(19).…”

Food-borne diseases associated with frozen berries consumption: a historical perspective, European Union, 1983 to 2013

“…Three of these four events occurred in 2013 and resulted in border rejection of the food consignment or in product recall. The remaining 23 events were distributed over a 15-year period from 1998 to 2013, and caused almost 14,000 reported human cases in 70 outbreaks in six EU countries, namely Denmark, Finland, France, Germany, the Netherlands and Sweden [2,[10][11][12][13][14][15][16][17][18][19]. The frozen berries implicated as food vehicles in 23 of 27 of the reported outbreak events were frozen raspberries.…”