The vomit machine lives on; norovirus can aerosolize during vomit events

I’ve been lucky to be close to some excellent projects, some of the stuff and knowledge created through these projects ends up mattering to food safety nerds – especially those who are making risk management decisions. Former NC State student Grace Tung-Thompson’s PhD project on vomit spray and norovirus is one of the most impactful. The work was carried out as part of the USDA NIFA-funded NoroCORE project led by my friend Lee-Ann Jaykus.VOMIT-BLOG-HEADER-698x393

I’ve talked to lots of Environmental Health Specialists, retailers and food service food safety folks about what Grace and fellow graduate student Dominic Libera put together and many respond with a weird level of enthusiasm for the barf project.

Mainly because a real question they struggle with is how far will virus particles travel from an up-chuck event – knowing this, and then cleaning and sanitizing helps limit the scope of a potential outbreak.  Grace’s work was published in PLOS ONE a while ago, we used it as a centerpiece for a Conference for Food Protection issue on vomit clean up in 2016 (which, maybe, could be included in the oft rumored 2017 Food Code) and the Daily Beast  covered the work today.

A couple of years ago, PhD student Grace Tung Thompson demonstrated something incredibly gross: When a person vomits, little tiny bits of their throw-up end up airborne. You could ingest them just by breathing air in the same room. As if that weren’t disconcerting enough, if the person got sick from a virus, there could be enough viruses in the air to get you sick, too. Just try not to think about that the next time the person in the row behind you throws up on an airplane.
So how do you get rid of airborne viruses? “There is no known technology that will eliminate norovirus if it’s in the air,” Jaykus said, “and there really aren’t a lot of technologies—safe technologies—that even are likely to work.” Her research team recently experimented with misting antiviral compounds into spaces as an alternative to disinfecting surfaces individually, and it worked, but not completely. This technique, known as fogging, can only be used in spaces that can be cleared out and contained, like bathrooms, for example. “I think we need that technology, and that technology is really, really important, but how the heck we’re going to develop it? I’m at a loss for words.”

From an individual perspective, the best you can do is get yourself far away from a vomiting incident; Jaykus recommends at least 100 feet. If you were in the middle of a meal at a restaurant and someone at the next table threw up, you’d probably be wise to stop eating, and to wash yourself and your clothes when you are able.

From the perspective of a restaurant owner, the best course of action is to do a really, really good job of the cleanup. Commercial vomit and fecal matter cleanup kits are catching on with bigger companies in the foodservice industry, says Jaykus. They provide personal protection, including disposable coveralls and respirator masks, in addition to the material required to pick up and wipe down the mess.

Katie’s Norovirus Nightmare

The NoroCORE Collaborative is running a series of posts for Halloween on norovirus nightmares. The first post comes from one of my graduate students, Katie Overbey.

During Spring Break of 2014 I was spent the week with my boyfriend in New Orleans and we stayed with my aunt. As one does in New Orleans, we ate lots of tasty food and tried lots of drinks. On the Saturday of our trip, after eating at my aunt’s favorite Mexican restaurant (side note: who eats Mexican food when they visit New Orleans?) she decided to take us on what has since been deemed the ‘drinking tour of the French Quarter.’ KatieOverbeyAfter about three hours I started to feel queasy right in the middle of the iconic Pat O’Briens Bar. We thought maybe I was hungry from our day of activities so we headed to get dinner. The place was packed and while waiting for our food, it hit me. I weaved through the crowd to get to the bathroom, just to discover that one stall was broken, the other was occupied and there was a line. I apologized to the people in line for what was about to happen and then proceeded to throw up in the sink, because as anyone who’s had norovirus knows – when it decides to hit, there’s not much you can do.

After cleaning up as best I could (though after my master’s research I now know that bathroom was doomed because of all my aerosolized vomit) we headed back to my aunt’s as fast as possible. I proceeded to get sick all night long, which ironically put a damper on the rest of my relaxing vacation.

At first, my aunt and boyfriend thought I had enjoyed the drinking tour too much, but I knew that what I had was way worse. I suspect that it had something to do with the Mexican food because after my aunt ate some of my leftovers, she got sick too.

Katie Overbey is an MS student in Food Science at NC State studying how to better communicate with schools having norovirus outbreaks and environmental detection of norovirus

Norovirus surrogates are tough to inactivate in cotton and polyester

A couple of years ago Sam, the almost-5-year-old yacked all over the backseat of the van on a car trip. The polyester carpeting and cotton fabric-covered seats smelled for weeks. We even tried to hose the van out, leaving the doors open for a couple of days (and then a frog set up shop in there).

It was most likely motion sickness that led to Sam’s vomit event, but people with noro puke on all sorts of surfaces. My friend Angie Fraser and colleagues at Clemson just published what happens when you try to inactivate norovirus surrogates on different surfaces including polyester and glass.

From the discussion: images

Our results indicated that surface and virus type had a significant influence on RE (that’s recovery efficiency – ben). We found that both FCV and MNV exhibited higher RE when inoculated onto glass than either polyester or cotton. In addition, the recovery of both viruses from cotton was significantly lower than that of polyester. Compared with FCV, MNV exhibited a higher recovery from soft porous surfaces; however, it was only significant for cotton. Previous studies have also document- ed the ability of HuNoV surrogates to be recovered with greater efficiency from hard nonporous surfaces than from soft porous surfaces. Viruses may become more tightly bound to soft porous surfaces due to their ability to absorb the virus-containing media and trap viruses in the subsurface.

Recovery and Disinfection of Two Human Norovirus Surrogates, Feline Calicivirus and Murine Norovirus, from Hard Nonporous and Soft Porous Surfaces

Journal of Food Protection, Number 10, October 2015, pp. 1776-1924, pp. 1842-1850(9)

Yeargin, Thomas; Fraser, Angela; Huang, Guohui; Jiang, Xiuping

Abstract:

Human norovirus is a leading cause of foodborne disease and can be transmitted through many routes, including environmental exposure to fomites. In this study, both the recovery and inactivation of two human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), on hard nonporous surfaces (glass) and soft porous surfaces (polyester and cotton) were evaluated by both plaque assay and reverse transcription quantitative PCR method. Two disinfectants, sodium hypochlorite (8.25%) and accelerated hydrogen peroxide (AHP, at 4.25%) were evaluated for disinfection efficacy. Five coupons per surface type were used to evaluate the recovery of FCV and MNV by sonication and stomaching and the disinfection of each surface type by using 5 ml of disinfectant for a contact time of 5 min. FCV at an initial titer of ca. 7 log PFU/ml was recovered from glass, cotton, and polyester at 6.2, 5.4, and 3.8 log PFU/ml, respectively, compared with 5.5, 5.2, and 4.1 log PFU/ml, respectively, for MNV with an initial titer of ca. 6 log PFU/ml. The use of sodium hypochlorite (5,000 ppm) was able to inactivate both FCV and MNV (3.1 to 5.5 log PFU/ml) below the limit of detection on all three surface types. AHP (2,656 ppm) inactivated FCV (3.1 to 5.5 log PFU/ml) below the limit of detection for all three surface types but achieved minimal inactivation of MNV (0.17 to 1.37 log PFU/ml). Reduction of viral RNA by sodium hypochlorite corresponded to 2.72 to 4.06 log reduction for FCV and 2.07 to 3.04 log reduction for MNV on all three surface types. Reduction of viral RNA by AHP corresponded to 1.89 to 3.4 log reduction for FCV and 0.54 to 0.85 log reduction for MNV. Our results clearly indicate that both virus and surface types significantly influence recovery efficiency and disinfection efficacy. Based on the performance of our proposed testing method, an improvement in virus recovery will be needed to effectively validate virus disinfection of soft porous surfaces.

NC State researchers show copper affects norovirus capsid

Matt Shipman, public information officer at NC State University and curator of The Abstract writes, norovirus affects an estimated 20 million Americans every year, and the hardy virus can linger on exposed surfaces for weeks – making it difficult to stop the spread of the disease. But a new finding from NC State researchers shows that an age-old commodity may be a new tool in combating norovirus: copper.pennies-435cs051012-1

The researchers found that viral shells (being used as a stand-in for norovirus) that were in contact with copper alloys for at least ten minutes became effectively neutralized. In other words, the finding means that virus particles that land on a copper doorknob or counter-top would no longer be capable of causing a norovirus infection.

The work holds promise for helping to limit the spread of norovirus infection via “environmental contamination” in places like hospitals or doctor’s offices.

A paper on the finding, “Destruction of the Capsid and Genome of GII.4 Human Norovirus Occurs During Exposure to Metal Alloys Containing Copper,” is published online in the journal Applied and Environmental Microbiology. The paper was authored by NC State researchers Chip Manuel, Matt Moore, and Lee-Ann Jaykus, who are part of the NoroCORE research collaborative. NoroCORE stands for the Norovirus Collaborative for Outreach, Research, and Education, and involves more than 30 research teams from 18 institutions. It is funded through a $25 million grant awarded by the USDA National Institute of Food and Agriculture.

More information on the work is also available on the site of the American Society for Microbiology.