Multistate Outbreak of Norwalk-like Virus Gastroenteritis Associated with a Common Caterer

Abstract

In February 2000, an outbreak of gastroenteritis occurred among employees of a car dealership in New York. The same meal was also supplied to 52 dealerships nationwide, and 13 states reported illness at dealerships where the banquet was served. A retrospective cohort study was conducted to identify risk factors associated with the illness. Stool samples were collected to detect Norwalk-like virus, and sera were drawn and tested for immunoglobulin A antibodies to the outbreak strain. By univariate analysis, illness was significantly associated with consumption of any of four salads served at the banquet (relative risk = 3.8, 95% confidence interval: 2.5, 5.6). Norwalk-like virus was detected by reverse transcription-polymerase chain reaction assay in 32 of 59 stool samples from eight states. Nucleotide sequences of a 213-base pair fragment from 16 stool specimens collected from cases in eight states were identical, confirming a common source outbreak. Two of 15 workers at caterer A had elevated immunoglobulin A titers to an antigenically related Norwalk-like virus strain. This study highlights the value of molecular techniques to complement classic epidemiologic methods in outbreak investigations and underscores the critical role of food handlers in the spread of foodborne disease associated with Norwalk-like virus.

Genetic and Epidemiologic Trends of Norovirus Outbreaks in the United States from 2013 to 2016 Demonstrated Emergence of Novel GII.4 Recombinant Viruses

“…Region C-negative samples were genotyped using a region D protocol as described previously (27). A novel RT-PCR (P-C typing assay) was performed by using a combination of previously published oligonucleotide primers: primers MON432 (TGG ACI CGY GGI CCY AAY CA) and G1SKR (CCA ACC CAR CCA TTR TAC A) for GI viruses; primers MON431 (TGG ACI AGR GGI CCY AAY CA) and G2SKR (CCR CCN GCA TRH CCR TTR TAC AT) for GII viruses (12,28). For GI viruses, the expected PCR product size is ϳ543 bp, and for GII viruses it is ϳ557 bp.…”

Norovirus

“…Norovirus outbreaks in restaurants and canteens have been documented and have been linked to catering companies, with the extent of outbreaks varying from several isolated cases to large multistate events. In one outbreak investigated by the U.S. CDC, illnesses in 13 states among 333 people were tied to workers at a single caterer providing "boxed lunches" to series of car dealerships (131). The food preparation environment has been evaluated for reservoirs of viral persistence and methods of enhanced cleaning to reduce transmission (132).…”

Evaluation of Liquid- and Fog-Based Application of Sterilox Hypochlorous Acid Solution for Surface Inactivation of Human Norovirus

“…NV outbreaks in these common settings have economic impacts resulting from the costs to disinfect affected areas to prevent the spread and recurrence of NV infection, the likely shutdown of workplaces, and the hospitalizations of affected persons. The main modes of transmission are via the fecal-oral route by consumption of contaminated foods or water (4,5,26,27), by direct or indirect person-to-person transmission via hands or fomite transfer (11,12,14,17,23,35), or by airborne contamination. NV outbreaks are difficult to control due to the viruses' having high attack rates, environmental stability, and a low human infectious dose estimated to be between 10 and 100 virions per 50% human infectious dose (10).…”