Norovirus is one of the most common foodborne illnesses and is the leading cause of illness and outbreaks from contaminated food in the United States. Leading health experts recommend hand hygiene and cleaning and disinfecting contaminated surfaces as two measures restaurant workers can take to reduce the transmission of norovirus. Yet, how do we know if the products we are using are effective in killing norovirus?
Laboratory Testing – Cultivating the Virus
In order to test product efficacy against human noroviruses (HuNoVs), we need to cultivate viruses in cells in laboratory conditions. Different from bacteria and fungi that grow in a Petri dish, which contains a medium such as food for their replication, viruses need alive host cells in order to replicate, or make copies of themselves. In some instances, we can keep some of these cells alive outside of the host organism, and under the right conditions, get viruses to infect these cells and replicate in a laboratory. Once this point is reached, it opens up enormous possibilities for research.
The major barrier in research and development of effective interventions for HuNoVs has been the lack of a robust and reproducible in vitro cultivation system. HuNoVs have been difficult to be cultivated in vitro despite numerous efforts over the last 40 years.
The lack of a reproducible culture system for HuNoVs has forced scientists researching norovirus to use surrogates for studies and for testing disinfectants and other products to show efficacy against the Human Norovirus. Many products available in the market today that claim Norovirus efficacy are based on tests using HuNoVs surrogates. However, despite several similarities surrogates have with HuNoVs, they are not the same.
A Breakthrough in Science
The good news, a group of scientists from Baylor College of Medicine have successfully cultured the human norovirus in intestinal cells. This culture system simulates the human intestinal epithelium, permits human host-pathogen studies of previously non-cultivatable pathogens, and allows the assessment of methods to prevent and treat HuNoV infections such as vaccines, therapeutics and other measures to control the virus in humans, including how we manage norovirus transmission. The new methodology has been tested in different research labs thorough the country and has shown reproducibility and viability.
Although it may take some time for the in-vitro methodology to be available at commercial labs, it is a first step towards measuring how effective disinfectants and food processes are in inactivating infectious HuNovs, which can lead to enhanced guidelines for preventing virus spread, and better products that show efficacy against HuNovs.
So what does this breakthrough in science mean to restaurant owners and operators? It means that as science advances so will your surface disinfecting and sanitizing products. Be sure to be aware of claims products make and ask questions about the safety and effectiveness of the products. You want to be certain the product has been tested against common viruses to ensure the safety of your employees and guests.
For more details, read:
Replication of human noroviruses in stem cell–derived human enteroids
BY KHALIL ETTAYEBI, SUE E. CRAWFORD, KOSUKE MURAKAMI, JAMES R. BROUGHMAN, UMESH KARANDIKAR, VICTORIA R. TENGE, FREDERICK H. NEILL, SARAH E. BLUTT, XI-LEI ZENG, LIN QU,BAIJUN KOU, ANTONE R. OPEKUN, DOUGLAS BURRIN, DAVID Y. GRAHAM, SASIREKHA RAMANI,ROBERT L. ATMAR, MARY K. ESTES
PUBLISHED ONLINE25 AUG 2016
DOI: 10.1126/science.aaf5211
