Norovirus inside leafy greens

Lettuce has been implicated in human norovirus (HuNoV) outbreaks. The virus is stable on the leaf surface for at least 2 weeks; however, the dynamics of virus internalization have not been fully investigated. The purpose of this study was to assess the internalization and distribution of HuNoV and two surrogate viruses, porcine sapovirus (SaV) and Tulane virus (TV), in lettuce and spinach.

Viral inoculations through the roots of seedlings and the petiole of leaves from mature plants were performed, and the viruses were tracked on days 1 and 6 post-root inoculation and at 16 h and 72 h post-petiole inoculation. Confocal microscopy was used to visualize root-internalized HuNoV.

In both lettuce and spinach, (i) HuNoV was internalized into the roots and leaves at similar RNA titers, whereas surrogate viruses were more restricted to the roots, (ii) all three viruses were stable inside the roots and leaves for at least 6 days, and (iii) HuNoV disseminated similarly inside the central veins and leaf lamina, whereas surrogate viruses were more restricted to the central veins. Infectious TV, but not SaV, was detectable in all tissues, suggesting that TV has greater stability than SaV. HuNoV was visualized inside the roots’ vascular bundle and the leaf mesophyll of both plants.

In conclusion, using surrogate viruses may underestimate the level of HuNoV internalization into edible leaves. The internalization of HuNoV through roots and cut leaves and the dissemination into various spinach and lettuce tissues raise concerns of internal contamination through irrigation and/or wash water.

IMPORTANCE Human noroviruses are the leading cause of foodborne outbreaks, with lettuce being implicated in the majority of outbreaks. The virus causes acute gastroenteritis in all age groups, with more severe symptoms in children, the elderly, and immunocompromised patients, contributing to over 200,000 deaths worldwide annually. The majority of deaths due to HuNoV occur in the developing world, where limited sanitation exists along with poor wastewater treatment facilities, resulting in the contamination of water resources that are often used for irrigation.

Our study confirms the ability of lettuce and spinach to internalize HuNoV from contaminated water through the roots into the edible leaves. Since these leafy greens are consumed with minimal processing that targets only surface pathogens, the internalized HuNoV presents an added risk to consumers. Thus, preventive measures should be in place to limit the contamination of irrigation water. In addition, better processing technologies are needed to inactivate internalized viral pathogens.

Tissue distribution and visualization of internalized norovirus in leafy greens

April 2018

Applied Environmental Microbiology, vol.84 no.12

Malak A. EsseiliaTea MeuliabLinda J. Saifa and Qiuhong Wanga

 doi:10.1128/AEM.00292-18

http://aem.asm.org/content/84/12/e00292-18.abstract?etoc

From the (written) barf: Goodbye Jimmy-self-serve buffet on Holland America cruises

Holland America cruise line has all but put an end to the self-serve buffet.

Darren Cartwright of Yahoo News writes the Holland America Line has literally taken a hands-on, or make that hands-off, approach and heavily restricted self-service in the general dining areas of its ships.

The move could be just what’s needed to restore Australia’s faith in the industry following four gastro outbreaks on Holland America’s sister line Princess Cruises over the past 15 months.

The most recent was in January when some 200 passengers went down with the norovirus aboard the Sea Princess during a tour of New Zealand.

Both Holland America and Princess are subsidiaries of the Carnival Corporation, which has a number of cruise lines including P&O Australia and Cunard.

I take a tour around Asia on Holland America’s Volendam, which can cater for up to 1450 guests. I quickly notice that the grab’n’go treats are behind glass in the Lido Market dining room, where there’s an abundance of big-smiling waiting staff ready to serve me.

Only pre-plated desserts and pre-made and wrapped sandwiches can be retrieved from the general buffet area. All other meals are carried out to guests.

There are only a few areas where passengers can treat themselves, including the poolside taco servery, while in the bars, nuts are delivered in mini-carafes and have to be poured out to be consumed.

The Volendam’s hotel director Craig Oates says the reduction in self-service has been gradual and is purely to enhance the guest experience and not related to concerns over passenger hygiene.

“I joined 14 years ago and a lot of it was self-service but it’s slowly transitioned. It has not been an overnight decision to restrict self-service,” Mr Oates told AAP.

“The reason we have people making salads is, rather than people helping themselves and getting mixed up with the dressings, we wanted to add something to the guest experience.”

Proms are overrated: 111 students fall ill after prom at Chicago’s Shedd Aquarium

I was perusing a paper this morning about establishing an appropriate bionome for a large-scale, salt-water aquarium, because that’s what microbiological nerds do (but could a virus take out the microorganisms? probably) when I read that at least 111 students from a suburban high school became ill with stomach flu-like symptoms after their Friday night prom at the Shedd Aquarium.

I never went into the prom thing, probably because my high-school girlfriend broke my heart (or did I break her’s?).

According to CLTV, roughly 400 students from Andrew High School in Tinley Park, Ill., celebrated prom at the aquarium at 1200 S. Lake Shore Dr. on Friday. By Saturday and Sunday, some students started to come down with fevers, chills, vomiting and diarrhea. It is still too soon to tell whether the illness is norovirus.

Officials originally reported that 50 students were ill. By Tuesday morning, the number had climbed to 111.

A spokeswoman for Shedd said the aquarium’s food provider, Sodexo, was investigating. Shedd did “an extra precautionary deep clean of the aquarium” Monday; no one at additional private events hosted at the aquarium since Friday became ill.

“At this time, we do not believe there are any safety concerns related to food or drink being served to our guests visiting the aquarium,” spokeswoman Andrea Rodgers said.

All known details have been reported to the Chicago Department of Public Health.

Marci Condon said her son Jack, a football player at Andrew, was still sick in bed Monday. Dozens of students went to Kalahari Resort in Wisconsin Dells and became sick there. Others fell ill on trips to Indiana, Michigan and Six Flags Great America.

“Clearly, my heart goes out to all our kids and their families who were affected,” Principal Bob Nolting said in a statement. “We have many individuals who work very hard on creating a prom experience that is enjoyable and meaningful. It is saddening to see the excitement of an otherwise positive and memorable event dampened by this situation.”

The Shedd Aquarium’s initial full statement is below:

The care and well-being of all our guests is a top priority for Shedd Aquarium and something that is taken very seriously.  Upon learning Monday morning about alleged food-related illness reported by a number of students who attended the Victor J. Andrew High School Prom at the aquarium Friday evening, Shedd Aquarium management notified our food service provider Sodexo, and Sodexo leadership began to take immediate action to investigate further. Shedd and Sodexo are in regular contact with the school’s administrative office and have reported all known details to the Chicago Department of Public Health.  At this time, we do not believe there are any safety concerns related to food or drink being served to our guests visiting the aquarium.

Sodexo services at Shedd Aquarium has a longstanding, strong performance in food safety and commitment to maintain strict adherence to food safety procedures that lead to clean, safe operations and nutritious food. We welcome health inspections and aggressively self-monitor as well.

Andrea Rodgers, APR

Vice President, Communications & Public Relations

Reality research: Norovirus in restaurant bathrooms

Long-time friend and friend of the barfblog.com, Don Schaffner, a professor of microbiology at Rutgers University (right, sort of as shown) writes:

More than seven years ago I had the good fortune to be contacted by my colleague, Dr. Lee-Ann Jaykus (below, left, exactly as shown).

She asked if I wanted to be involved in what was at the time going to be a remarkable endeavor. She was going to lead a team of scientists competing to earn a $25 million grant from the USDA focused on understanding Norovirus.

Norovirus causes more foodborne disease than any other microorganism. Because it is often self-limiting, and seldom fatal, it gets a little attention. It’s also a remarkably difficult organism to study. One of the reasons it has been difficult to study is that there had no way to culture the organism outside it’s human host. This meant that anyone wanting to do research with the organism had to have a supply of frozen poop containing the virus.

One of the goals of the ambitious project lead by Dr. Jaykus was to finally crack the code which would allow scientists to culture the virus in the laboratory. Spoiler alert, we got the grant. We were all excited to learn recently that thanks in large measure to the USDA Grant, that riddle has been solved.

This USDA Grant also allowed a number of other research projects too numerous to recount here, but I do want to tell the story of one.

Early on in our efforts on the ground, my colleague, Angie Fraser reached out and asked if I wanted to be part of an extensive survey of restaurant bathroom for Norovirus. I was delighted to say yes, and we began

I have to express my sincere appreciation to Cortney Leone whom led the project. She had the unenviable task of having to oversee researchers in three U.S. states, charged with collection of the data for this project. I also owe huge debt of gratitude to my graduate student Hannah Bolinger who led our data collection efforts in New Jersey.  Thanks also to the NJ team of graduate students, undergraduate students and significant others who visited public bathrooms around the state (Louis Huang, Pierce Gaynor, Sarah Hossain, Sneha Sreekumar, Jenny Todd-Searle, and Arthur Todd-Searle).

(Schaffner, this isn’t an Academy Award acceptance speech, on with it — dp.)

Because we wanted to ensure that our data were representative, we collected data from nine different counties in New Jersey. This turned out to be a lot harder than you might think. New Jersey is a home rule state.

This means that public health operates at the municipal level, with minimal oversight from the state. Our first task was to compile lists of food service establishment from the three regions of New Jersey.

This was easy to do in less densely populated regions, where the municipal entity was the county. We could simply contact the county, and through appropriate freedom of information act paperwork, obtain a list of all of the restaurants in the county. This was far more difficult in the densely settled parts of the state, where obtaining a list require contacting each and every municipality in the county, and filling out each municipalities’ different paperwork, in some cases mailing a paper check to cover photocopying costs, and then eventually taking the information we received back, and putting it into a standardized database. All of this was required before we could even begin to collect the first piece of data.

Thanks to Hanna’s outstanding work, we were eventually able to produce a robust enough database that we could proceed with data collection. Hannah lead a team of students that visited restrooms in and around New Jersey. This was harder than it sounded, as often the information provided by the  municipalities was out of date, and the students arrived at a location, only to learn that the restaurant was closed, or the location was incorrect.

Eventually, the teams in all three states had collected enough swabs and sent the samples back to CDC for analysis.

The end result of all this work was published in the Journal of Food Protection. Although our goal was to visit 750 commercial food establishments, we actually visited 751 establishments, in which 1,044 bathrooms and 4,163 surfaces were swabbed.  Four swab samples were collected from each bathroom: (i) the underside of the toilet seat where it connects to the toilet bowl, (ii) the flush handle of the toilet, (iii) the inner door handle of the stall door or, when there was no stall door, the inner door handle of the outer door, and (iv) the hot water knob of the sink faucet.

In the end 61 (1.5%) of 4,163 swabs were presumptively positive for human norovirus, and 9 of these were confirmed by sequencing.  This is similar to what others have found.

Almost half (30) of positive swabs were found on the underside of the toilet seat. About 20% were found on the toilet flush handle (13) and the inner handle of the stall or outer door (11). Only 11% (7) of positive swabs were found on the sink faucet handle.  Our results suggest that areas further away from the toilet are less likely to harbor norovirus contamination; toilet surfaces (especially the underside of the seat) would be closest to vomiting and diarrheal events during which high numbers of norovirus particles could be shed.

Chain restaurants had significantly more positive samples than non-chains (p = 0.0273). Unisex bathrooms had significantly more positive samples than female bathrooms (p = 0.0163).  Bathrooms with bar soap had significantly more positive samples than liquid soap bathroom (p = 0.0056) and foam soap bathrooms (p = 0.0147), but note that only 3 bathrooms out of 751 actually used bar soap. Bathrooms containing a trash can attached to the paper towel dispenser had significantly more positive samples than bathrooms with a free-standing trash can (p = 0.0004).

Although[the NoroCORE grant recently ended,I know there will be continued publications coming for many years, several of which will come from my lab, that will serve to further advance our understanding of Norovirus, and the means by which it can be controlled.

Prevalence of Human Noroviruses in Commercial Food Establishment Bathrooms

CORTNEY M. LEONE, MUTHU DHARMASENA, CHAOYI TANG, ERIN DiCAPRIO, YUANMEI MA, ELBASHIR ARAUD, HANNAH BOLINGER, KITWADEE RUPPROM, THOMAS YEARGIN, JIANRONG LI, DONALD SCHAFFNER, XIUPING JIANG, JULIA SHARP, JAN VINJÉ, and ANGELA FRASER (2018) Prevalence of Human Noroviruses in Commercial Food Establishment Bathrooms. Journal of Food Protection: May 2018, Vol. 81, No. 5, pp. 719-728.

https://doi.org/10.4315/0362-028X.JFP-17-419

http://jfoodprotection.org/doi/abs/10.4315/0362-028X.JFP-17-419?code=fopr-site

Although transmission of human norovirus in food establishments is commonly attributed to consumption of contaminated food, transmission via contaminated environmental surfaces, such as those in bathrooms, may also play a role. Our aim was to determine the prevalence of human norovirus on bathroom surfaces in commercial food establishments in New Jersey, Ohio, and South Carolina under nonoutbreak conditions and to determine characteristics associated with the presence of human norovirus. Food establishments (751) were randomly selected from nine counties in each state. Four surfaces (underside of toilet seat, flush handle of toilet, inner door handle of stall or outer door, and sink faucet handle) were swabbed in male and female bathrooms using premoistened macrofoam swabs. A checklist was used to collect information about the characteristics, materials, and mechanisms of objects in bathrooms. In total, 61 (1.5%) of 4,163 swabs tested were presumptively positive for human norovirus, 9 of which were confirmed by sequencing. Some factors associated with the presence of human norovirus included being from South Carolina (odd ratio [OR], 2.4; 95% confidence interval [CI], 1.2 to 4.9; P < 0.05) or New Jersey (OR, 1.7; 95% CI, 0.9 to 3.3; 0.05 < P < 0.10), being a chain establishment (OR, 1.9; 95% CI, 1.1 to 3.3; P < 0.05), being a unisex bathroom (versus male: OR, 2.0; 95% CI, 0.9 to 4.1; 0.05 < P < 0.10; versus female: OR, 2.6; 95% CI, 1.2 to 5.7; P < 0.05), having a touchless outer door handle (OR, 3.3; 95% CI, 0.79 to 13.63; 0.05 < P < 0.10), and having an automatic flush toilet (OR, 2.5, 95% CI, 1.1 to 5.3; 0.05 < P < 0.10). Our findings confirm that the presence of human norovirus on bathroom surfaces in commercial food establishments under nonoutbreak conditions is a rare event. Therefore, routine environmental monitoring for human norovirus contamination during nonoutbreak periods is not an efficient method of monitoring norovirus infection risk.

Norovirus that sickened over 200 in 2015 was more than ‘technical difficulties’

A man who barfed in the foyer of Toby’s Carvery at the Exeter Arms, Middlemoor, UK, on the evening of Sunday, March 29, 2015 tested positive for Norovirus.

The restaurant closed, reopened, and then reclosed two days later for “technical difficulties” after at least 100 people subsequently were sickened by noro, including all 24 staff at a local charity, the Cat Protection League, who visited the restaurant for a leaving meal for a deputy manager.

The Mid-Devon Advertiser reports the pub and restaurant, which are owned and run by the brewers Mitchells and Butlers, have applied to the court to have the case dismissed and have commissioned their own specialist reports.

Mitchells and Butlers, which is based at Fleet Street, Birmingham, runs 1,784 pubs and restaurants all over Britain including the Toby Carvery, All Bar One, Browns, and Harvester chains.

They are accused of a single offence under the Health and Safety at Work Act of failing to ensure the safety of customers at the Toby Carvery in Exeter between March 28 and April 8, 2015.

The charge specifies that they ’failed to conduct an undertaking in such a way as to ensure, as far as reasonably practicable, that persons not in their employment who may have been affected thereby, were not exposed to risks to their health and safety’.

Mr John Cooper, QC, defending, asked that the company should not be asked to enter a plea until a special hearing on their application to dismiss the case had been heard.

He said they also intend to argue that the case is an abuse of process.

Mr Simon Morgan, prosecuting on behalf of Exeter City Council, said they plan to serve more expert evidence in the next few weeks.

Raw is risky: Norovirus outbreak linked to raw oysters rises to 126 in BC

In a follow-up on the norovirus outbreak linked to the consumption of British Columbia raw oysters, The Public Health Agency of Canada has reported that a total of 126 cases of gastrointestinal illness linked to oyster consumption have been reported in three provinces: British Columbia (92), Alberta (9), and Ontario (25). No deaths have been reported.

Ensure oysters are fully cooked before consuming them. Lightly cooking oysters does not kill norovirus. Oysters need to be cooked to an internal temperature of 90° Celsius (194° Fahrenheit) for a minimum of 90 seconds in order to kill norovirus.

39 sick with Norovirus from frozen mussels in Spain

The appropriately named Olive Press has reported 39 people have become infected by norovirus after eating contaminated frozen mussels.

The outbreak  occured in Valencia, but the infected batch had already been distributed to Andalucia, the Balearic Islands and nine other regions.

The Spanish Agency for Consumer Affairs, Food Safety and Nutrition has issued a warning to anyone who has bought frozen mussels from the batch to throw them away immediately.

The product is frozen cooked mussels from Galicia, called Mejillón media concha súper, under the Estrella Polar brand.

Any packaging containing the lot number 010DOP-18 should be thrown out.

The European Competent Authorities have also been informed through the Rapid Alert System for Food (RASFF).

Oysters contaminated with viral norovirus RNA in France

Following calls from RASFF and the Ministry of Health, the Dicastery once again issued a warning to recall the concealed oysters (Crassostrea gigas) bred in France contaminated by the Norovirus Genogroup GI marketed under the GISA brand SRL. The warning came from France, the country of origin of the molluscs, and came to Italy via the Rasff system, which sees the risk as serious.

 The new reference concerns many oysters, GTO 4024, packed by GISA SRL in the Anzio (RM) plant via Colle Cocchino 1 3 / A, in 3 kg boxes. The most aggressive virus under attack is Norovirus. Pathogen for which there is currently no vaccine.

We’re still all hosts on a viral planet: How Norovirus infection gets its start

Norovirus — the highly contagious gastrointestinal illness best known for spreading rapidly on cruise chips, in nursing homes, schools and other densely populated spaces — kills an estimated 200,000 people annually, mostly in the developing world. There’s no treatment or vaccine to prevent the illness, and scientists have understood little about how the infection gets started.

Now, researchers at Washington University School of Medicine in St. Louis have shown, in mice, that the virus infects a rare type of intestinal cell called a tuft cell, so named because each cell sports a cluster of hairlike extensions on its surface. While tuft cells are few in number, the scientists’ findings indicate that once the virus strikes, such cells multiply the virus quickly and set off severe infections.

The research, published April 12 in Science, suggests that targeting tuft cells with a vaccine or a drug may be a viable strategy for preventing or treating norovirus infections.

“Norovirus is one of the deadliest human pathogens that we know the least about,” said first author Craig B. Wilen, MD, PhD, an instructor in pathology and immunology. “Of the viruses worldwide for which there are no antiviral drugs or vaccines, norovirus arguably kills the most people. This study provides a therapeutic avenue to explore.

Norovirus causes severe vomiting and diarrhea that can develop suddenly. The virus is shed in the feces and vomit — sometimes for months after symptoms resolve — and spreads through people-to-people contact, by touching contaminated surfaces and then the mouth, or eating food contaminated with the virus.

Human norovirus can’t be grown easily in a lab, and for this reason, the researchers choose to study it in mice.

“We were most surprised that the virus infects such a rare cell type and that even with so few cells infected, the infections can be intense and easily transmitted,”Wilen said. “In a single mouse, for example, maybe 100 cells will be infected, which is very few compared with other viruses such as the flu.”

Tuft cells are a type of epithelial cell that protrudes into the intestine. They also are known to detect parasitic and worm infections in the gut and trigger an immune response. Such infections can make norovirus infections worse and may explain why people in the developing world – where intestinal parasites and worm infections are more common – also are more likely to die of norovirus.

But, until now, scientists didn’t understand how norovirus could be linked to intestinal parasite and worm infections. The new study indicates that such infections in the mice cause the number of tuft cells to increase by five- to tenfold, leading the norovirus to replicate more efficiently.

Treating the mice with a powerful broad-spectrum antibiotic cocktail decreased the number of tuft cells and the risk of norovirus infection. But, Wilen cautioned, the antibiotics used in the study would not be practical to give to patients because they would deplete gut microbes that keep the body healthy. Still, the finding points to gut bacteria’s role in facilitating norovirus infection.

The researchers, including Herbert W. “Skip” Virgin, MD, PhD, now at Vir Biotechnology, also noted that noroviruses tucked inside tuft cells are effectively hidden from the immune system, which could explain why some people continue to shed virus long after they are no longer sick. These “healthy carriers” are thought to be the source of norovirus outbreaks, so understanding how the virus evades detection in such people could lead to better ways to prevent outbreaks.

“This raises important questions about whether human norovirus infects tuft cells and whether people who have chronic norovirus infections and continue to shed the virus long after infection do so because the virus remains hidden in tuft cells,” Wilen said. “If that’s the case, targeting tuft cells may be an important strategy to eradicate the virus.”

How Norovirus infection gets its start

12.apr.18

Washington University School of Medicine

Wilen CB, Lee S, Hsieh L-Y, Orchard RC, Desai C, Hykes Jr. BL, McAllaster MR, Balce DR, Feehley T, Brestoff JR, Hickey CA, Yokoyama CC, Wang Y-T, MacDuff DA, Kreamalmayer D, Howitt MR, Neil JA, Cadwell K, Allen PM, Handley SA, van Lookeren Campagne M, Baldridge MT and Virgin HW

https://www.brightsurf.com/news/article/041218454105/how-highly-contagious-norovirus-infection-gets-its-start.html

Almost 2100 sickened: Noro in dried seaweed in Japan, 2017

Seven foodborne norovirus outbreaks attributable to the GII.P17-GII.17 strain were reported across Japan in 2017, causing illness in a total of 2,094 persons. Nori (dried shredded seaweed) was implicated in all outbreaks and tested positive for norovirus. Our data highlight the stability of norovirus in dehydrated food products.

Foodborne outbreaks caused by human norovirus GII.P17-GII.17-contaminated Nori, Japan, 2017

Emerging Infections Diseases, Volume 24, Issue 5, May 2018,  https://doi.org/10.3201/eid2405.171733

Naomi Sakon, Kenji Sadamasu, Takayuki Shinkai, Yousuke Hamajima, Hideaki Yoshitomi, Yuki Matsushima, Rika Takada, Fumio Terasoma, Asako Nakamura, Jun Komano, Koo Nagasawa, Hideaki Shimizu, Kazuhiko Katayama, and Hirokazu Kimura

https://wwwnc.cdc.gov/eid/article/24/5/17-1733_article