Norovirus Intervention Strategies in Retail Food Safety Programs
Grady Bergquist, RS
Environmental Health Specialist II, City of Lubbock Environmental Health Department
Abstract
Norovirus is the leading cause of foodborne illness in the United States and costs the United States billions of dollars in healthcare costs and decreased productivity. (Burke, et al., 2020) When an individual is infected and shedding Norovirus, they can disperse billions of viral particles. A healthy person can become infected with only a small number of viral particles. (CDC, 2020). The Centers for Disease Control and Prevention (CDC) recommends, but does not require, states to report norovirus cases. Currently, 12 states voluntarily report norovirus cases to CDC. Through interviews with state retail food safety program directors concerning norovirus intervention strategies used within their jurisdictions, and by obtaining outbreak data from CDC, CaliciNet, and the National Outbreak Reporting System (NORS). Review of telephone interviews, questionnaires, and NORS data revealed no discernable trends between intervention strategies of retail food safety programs and reduction in case numbers of norovirus illnesses. Emphasis is placed on further study of intervention strategies and information retention of food facilities before, during, and after outbreak investigations.
Key words: Norovirus, Intervention, Strategies, Foodborne, Contributing Factors
Norovirus Intervention Strategies in Retail Food Safety Programs
Background
Noroviruses are a group of non-enveloped, single-stranded ribonucleic acid viruses belonging to the family Caliciviridae (Robilotti, Deresinski, and Pinsky, 2015). While there are many variants of norovirus, genotype GII.4 is the leading cause of vomiting and diarrhea from acute gastroenteritis (inflammation of the stomach and intestines) among people of all ages in the United States (Pringle, et al., 2015). Each year, norovirus causes 19 to 21 million cases of acute gastroenteritis in the U.S. with a recent study estimating norovirus resulted in a $4.2 billion cost to health systems globally and a $60.3 billion societal cost. (Bartsch, Lopman, Ozawa, Hall, and Lee, 2016).
People infected with norovirus shed large quantities of viral particles with only a small number required to infect a healthy person. A person can contract the illness by having direct contact with an infected person, by consuming contaminated food or water, or by touching contaminated surfaces and then putting unwashed hands in their mouth. Contributing factors, such as bare hand contact, poor handwashing technique, and ill employees may determine the intervention strategies to be utilized by the retail food safety programs. In general, intervention strategies may vary from norovirus fact sheets provided by regulatory authorities to the presentation of norovirus research articles and supporting evidence to food facilities.
The process for reporting norovirus outbreaks starts with the local health department collecting specimens and epidemiologic data. Specimen genetic sequence data is reported to CaliciNet and epidemiologic data is reported to the National Outbreak Reporting System (NORS). The Centers for Disease Control and Prevention (CDC) reviews, summarizes, and publishes submitted information to the Norovirus Sentinel Testing and Tracking (NoroSTAT) network (CDC, 2020).
States are not required to report individual cases of norovirus illness to a national surveillance system. As a result, many cases are not known, and testing by hospitals and doctor’s offices is not conducted (CDC, 2020). NoroSTAT began reporting five states in 2012, with additional states joining over the next eight years. Currently, 12 states report norovirus outbreaks to the CDC and NoroSTAT national surveillance system. These states are Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, Ohio, Oregon, South Carolina, Tennessee, Virginia, Wisconsin, and Wyoming.
Studies on norovirus intervention strategies utilized in these reporting states compared to the number of reported norovirus cases have not been conducted.
Problem Statement
Trends relating to norovirus outbreaks and intervention strategies used in states and jurisdictions that currently report norovirus to CDC may not be known.
Research Questions
1. How are Retail Food Safety Programs utilized when investigating norovirus outbreaks in states and jurisdictions?
2. What intervention strategies do the states and jurisdictions employ to control norovirus in retail food establishments?
3. What correlations with contributing factors and intervention strategies exist within these states and jurisdictions?
Methodology
Norovirus outbreak data was obtained through the National Outbreak Reporting System (NORS) and was compiled by state, year, and categorized by food facility. Telephone interviews were conducted with food safety programs to determine norovirus intervention strategies employed by respective states and jurisdictions, and if contributing factors determine intervention strategies used. After obtaining information, intervention strategies were compared to the number of norovirus cases reported by each state to identify trends between intervention strategies and case numbers. Variety in intervention strategies and low numbers in reported cases would show a positive trend, inversely, few intervention strategies and high numbers of reported cases would show a negative trend.
Results
The retail food safety program managers from each of the 12 states were contacted by email, with four states responding to inquiries. Telephone interviews were then conducted with those four department managers.
Norovirus investigations in responding states are led by state or local epidemiologists, with retail food safety programs used in a supportive role while investigating retail food establishments. Minnesota reported having the largest role when investigating with stool sample collections, contact tracing, and employee health information.
Intervention strategies utilized by responding states are similar, using educational material from the CDC and educational presentations provided by the regulatory authority. Again, Minnesota reported having more in-depth intervention strategies of requiring food facilities to assess employees for illness and excluding them from food preparation as needed. Minnesota is the only responding state enrolled with EHS-Net, a collaborative online forum of environmental health specialists who follow up with food facilities after outbreak investigations (CDC, 2019).
Figure 1, below, portrays the number of cases reported by each state between 2012 and 2018. Minnesota reporting the highest number of cases, followed by Michigan, Oregon, and Nebraska.
Figure 1
Norovirus cases linked to food facilities from 2012-2018 in the four responding states
Conclusions
There are no identifiable trends relating to intervention strategies and the number of reported norovirus cases used by states that currently report norovirus to the CDC. All responding state retail food safety programs are used in a supporting role alongside their jurisdiction’s health departments during a norovirus outbreak. The states in which more intervention strategies are utilized by food safety programs, such as Minnesota’s enrollment in EHS-Net, does not show a reduced number of norovirus cases. The increase in cases could be attributed to several factors. For example, Minnesota’s enrollment in EHS-Net could increase awareness of norovirus and related illnesses to the general public, therefore increasing the number of tests and diagnoses of norovirus. All responding states utilize similar forms of educational outreach when investigating norovirus, while not reporting similar numbers in norovirus cases.
Recommendations
State and local norovirus intervention strategies in retail food safety programs are uniform among the four responding states, with the exception of Minnesota’s use of EHS-Net. Recommendations for improvement include:
1. A study on increased utilization of retail food safety programs by state and local health departments during norovirus and foodborne illness investigations
2. A study on efficacy of educational outreach and information retention among food workers in reporting states
3. An analysis of intervention strategies in the prevention and awareness of illness.
Acknowledgments
I would like to acknowledge the International Food Protection Training Institute for allowing me the opportunity to join like-minded individuals from across the nation in Cohort IX to expand upon my leadership abilities, self-management, and ability to work alongside others in a team environment. I also would like to acknowledge Wendy Fanaselle, with the FDA, for her assistance and expertise in Norovirus. Lastly, I would like to thank Stevan Walker and The City of Lubbock Environmental Health Department for their unending support and encouragement.
References
Bartsch, S. M., Lopman, B. A., Ozawa, S., Hall, A. J., & Lee, B. Y. (2016, April 26). Global economic burden of norovirus gastroenteritis. https://pubmed.ncbi.nlm.nih.gov/27115736/
Burke, R. M., Mattison, C., Pindyck, T., Dahl, R. M., Rudd, J., Bi, D., & Hall, A. J. (2020, April 14). The burden of norovirus in the United States, as estimated based on administrative data: Updates for medically attended illness and mortality, 2001 - 2015. https://pubmed.ncbi.nlm.nih.gov/32291450/
Centers for Disease Control and Prevention. (2018, December 07). National Outbreak Reporting System Dashboard https://wwwn.cdc.gov/norsdashboard/
Centers for Disease Control and Prevention. (2019, June 24). About ehs-net. https://www.cdc.gov/nceh/ehs/ehsnet/about.html
Centers for Disease Control and Prevention. (Ed.). (2020, October 08). Reporting and Surveillance for Norovirus https://www.cdc.gov/norovirus/reporting/index.html
Centers for Disease Control and Prevention. (2020, July 29). Norovirus virus classification. https://www.cdc.gov/norovirus/lab/virus-classification.html
Pringle, K., Lopman, B., Vega, E., Vinje, J., Parashar, U. D., & Hall, A. J. (2015, October 01). Noroviruses: Epidemiology, immunity and prospects for prevention. https://pubmed.ncbi.nlm.nih.gov/25598337/
Robilotti, E., Deresinski, S., & Pinsky, B. A. (2015). Norovirus. Clinical Microbiology Reviews, 28(1), 134-164. doi:10.1128/cmr.00075-14
Author Note
Grady Bergquist, Environmental Health Specialist II
City of Lubbock Environmental Health Department
This research was conducted as part of the International Food Protection Training Institute’s Fellowship in Food Protection, Cohort IX
Correspondence concerning this article should be addressed to:
Grady Bergquist, RS
City of Lubbock Environmental Health Department
1314 Ave. K, Lubbock, Texas, 79401
gbergquist@mylubbock.us
*Funding for this statement, publication, press release, etc., was made possible, in part, by the Food and Drug Administration through grant 5U18FD005964 and the Association of Food and Drug Officials. Views expressed in written materials or publications and by speakers and moderators do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices, or organization imply endorsement by the United States Government.