Approximately 14% of all norovirus outbreaks worldwide can be attributed to contaminated food, according to recent findings published in Emerging Infectious Diseases.
Researchers sought to determine the proportion of foodborne infections caused by noroviruses on a global scale, collecting data from 1999 to 2012 on norovirus transmissions and genotyping from three laboratory-based outbreak surveillance network databases — NoroNet, CalicNet and EpiSurv. A systematic review of norovirus outbreaks in peer-reviewed studies was also conducted.
Foodborne transmission was found to be responsible for 10% of all GII.4 genotype norovirus outbreaks, 27% of outbreaks caused by all other single genotypes, and 37% of outbreaks with combinations of GII.4 and other genotypes. When these profiles were applied to worldwide outbreak surveillance data from 2009 to 2012, the researchers found that of 1,332 outbreaks with an unknown mode of transmission, 14.5% could be attributed to food.
“Our study showed that the proportion of norovirus outbreaks attributed to foodborne transmission is comparable in different parts of the world,” the researchers wrote. “The proportion of norovirus outbreaks attributed to foodborne transmission is in the same order of magnitude as the 17% found in an expert elicitation study from the Netherlands and 11% in the United Kingdom as estimated from outbreak surveillance data. This similarity strongly indicates that this microbiology-based attribution method is robust, albeit in need of continued refinement.” – by Jen Byrne
Disclosure: The researchers report no relevant financial disclosures.