Rare Norovirus GIV Foodborne Outbreak, Wisconsin, USA

Leslie Barclay; Tim Davis; Jan Vinjé


Emerging Infectious Diseases. 2021;27(4):1151-1154. 

In This Article

Abstract and Introduction


We report a norovirus GIV outbreak in the United States, 15 years after the last reported outbreak. During May 2016 in Wisconsin, 53 persons, including 4 food handlers, reported being ill. The outbreak was linked to individually prepared fruit consumed as a fruit salad. The virus was phylogenetically classified as a novel GIV genotype.


Norovirus is the leading cause of epidemic and endemic acute gastroenteritis globally. The virus can be transmitted through person-to-person contact, consumption of fecally contaminated food or water, or self-contamination after touching contaminated environmental surfaces.[1,2] Noroviruses are divided into at least 10 genogroups (G), and viruses in GI, GII, GIV, GVIII, and GIX cause illness in humans.[3] More than 99% of all norovirus outbreaks are caused by GI and GII viruses in the United States.[4] GVIII includes 2 strains that have been detected in Japan during 2004 and 2011,[3] and GIX has caused 11 reported outbreaks in the United States since 2013 (https://www.cdc.gov/norovirus/reporting/calicinet/data.html).

GIV is divided into 2 recognized genotypes: GIV.1, which infects humans,[5] and GIV.2, which infects canines and felines.[6] GIV viruses were reported in humans in the Netherlands during 1998 and the United States during 1999[7,8] and have since been sporadically reported in clinical and environmental samples.[5,9–11] An outbreak linked to a GIV norovirus in the United States has not been reported since 2001.[4,8] In this article, we describe a 2016 foodborne norovirus outbreak associated with a novel GIV strain (tentatively GIV.NA).