Category Archives: Norovirus

Norovirus modeling: Stay at home after the barfing and pooping is gone

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Duret et al. write in Risk Analysis:

We developed a quantitative risk assessment model using a discrete event framework to quantify and study the risk associated with norovirus transmission to consumers through food contaminated by infected food employees in a retail food setting.

This study focused on the impact of ill food workers experiencing symptoms of diarrhea and vomiting and potential control measures for the transmission of norovirus to foods.

The model examined the behavior of food employees regarding exclusion from work while ill and after symptom resolution and preventive measures limiting food contamination during preparation.

The mean numbers of infected customers estimated for 21 scenarios were compared to the estimate for a baseline scenario representing current practices. Results show that prevention strategies examined could not prevent norovirus transmission to food when a symptomatic employee was present in the food establishment. Compliance with exclusion from work of symptomatic food employees is thus critical, with an estimated range of 75–226% of the baseline mean for full to no compliance, respectively.

Results also suggest that efficient handwashing, handwashing frequency associated with gloving compliance, and elimination of contact between hands, faucets, and door handles in restrooms reduced the mean number of infected customers to 58%, 62%, and 75% of the baseline, respectively.

This study provides quantitative data to evaluate the relative efficacy of policy and practices at retail to reduce norovirus illnesses and provides new insights into the interactions and interplay of prevention strategies and compliance in reducing transmission of foodborne norovirus.

Quantitative risk assessment of norovirus transmission in food establishments: Evaluating the impact of intervention strategies and food employee behavior on the risk associated with norovirus in foods

Risk Analysis, Vol. 37, No. 11, 2017

DOI: 10.1111/risa.12758

Duret et al.

http://onlinelibrary.wiley.com/doi/10.1111/risa.12758/epdf

 

Raw is risky: Norovirus in raw oysters sickens 10 in Denmark

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Joseph James Whitworth of Food Quality News writes 10 people have been sickened by norovirus after eating raw oysters at Danish restaurants.

Fødevarestyrelsen (Danish Veterinary and Food Administration) said oysters are from Lemvig.

The agency has closed the area in Lemvig for commercial harvest of mussels and oysters and is monitoring it.

Illnesses can be avoided if oysters are cooked to an internal temperature of 90° Celsius/194° Fahrenheit for a minimum of 90 seconds.

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

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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.

Blaming consumers: Cruise ship edition

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Jim Walker of Cruise Law News writes the Centers for Disease Control (CDC) reports that there was a gastrointestinal outbreak on the Crown Princess during its recent cruise, from October 25th to November 8, 2017. The Princess cruise ship departed Quebec, Canada on October 25th for a two-week cruise to Canadian and U.S. ports. The cruise ship arrived in Fort Lauderdale, Florida on November 8th and will begin its Caribbean season.

According to the CDC report, 184 passengers and 12 crew members became ill with gastro-like symptoms which included diarrhea.  

During the period from 2010 to the current date, Princess Cruises experienced the most outbreaks on its cruise ships calling on U.S. ports, according to the CDC. Princess reported twenty-one (21) cases to the CDC during this time period.

The Crown Princess alone has suffered through six (6) norovirus outbreaks since 2010 to the present. Before the current GI outbreak, the last norovirus outbreak on the Crown Princess was from January 3 – 18, 2016 and, before that, from October 18 to November 16, 2014. Earlier, there was a norovirus and e-coli outbreak from February 5 to 12, 2014. It also experienced back-to-back norovirus outbreaks from January 29 to February 4, 2012 and February 4 to February 9, 2012.

The cruise line with the second most outbreaks is Holland America Line with 18 cases of GI sicknesses reported to the CDC since 2010. HAL suffered norovirus outbreaks on the Nieuw Amsterdam, and two outbreaks each on the Voendam and the Noordam this year.  

So why is Princess Cruises far more prone to norovirus outbreaks than Carnival cruise lines, for example?

The cruise industry always blames the passengers for bringing the virus aboard, rather than its food handlers, or contaminated food or water. So are Princess Cruises customers the sickest and the least hygienic cruisers around? Are guests of HAL the second most unhygienic cruisers? Do they wash their hands the least of any cruisers? This seems like absurd arguments to make.

Whoever is to blame, the crew members, of course, always pay the price, by having to wipe and scrub and spray everything in sight for long 16+ hour days to try to disinfect a ship longer than three football fields.

Irrespective of the blame-game, don’t call us if you get sick on a cruise. Proving where the virus came from, or that the cruise line was negligent, is virtually impossible to prove, especially since the CDC conducts no epidemiological analysis and sometimes can’t even figure out whether the outbreak is due to norovirus, e-coli or something as exotic as Shigella sonnei or Cyclospora cayetanensis.

For example, The New Zealand Herald reports, a passenger on a cruise ship plagued with a vomiting and diarrhoea bug says he only learnt previous guests had been struck down with the same thing once they set sail.

Sydney man Walter Gibian and his wife Elisabeth left Sydney on October 30 on a 12-day Celebrity Solstice cruise travelling from Sydney to Auckland via the South Island so they could see New Zealand. Gibian had worked in New Zealand in 1980s and loved it so booked the cruise to see the East Coast.

The ship had left Melbourne when the captain announced to guests that passengers on an earlier cruise had norovirus and asked guests to take extra precautions including washing their hands regularly and using hand sanitiser.

any notification before they left and by this time it was too late to do anything about it as they were well on their way to New Zealand.

“It think people should be told and given the option that if you don’t like being exposed to this virus you are allowed to get off. But we found out when we were sea.”

Halfway into the 12-day cruise passengers started falling ill and Elisabeth came down with the bug on Saturday night. She was then isolated to her cabin for 48 hours.

“They (passengers) are sick all right. But of course the ship won’t tell us how many are sick, but my wife got sick on Saturday night. They are taking all sorts of precautions but it is still happening. They keep telling me, they are doing their utmost and they are doing their best but the fact is it is not effective.”

It was the ice: 144 students sickened in Taiwan, 2015

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On 5 March 2015, Taiwan Centers for Disease Control was notified of more than 200 students with gastroenteritis at a senior high school during excursion to Kenting. We conducted an outbreak investigation to identify the causative agent and possible vehicle of the pathogen.

Methods

We conducted a retrospective cohort study by using a structured questionnaire to interview all students for consumed food items during their stay at the resort. Students were defined as a gastroenteritis case while having vomiting or diarrhea after the breakfast on 4 March. We inspected the environment to identify possible contamination route. We collected stool or vomitus samples from ill students, food handlers and environmental specimens for bacterial culture for common enteropathogens, reverse transcription polymerase chain reaction (RT-PCR) for norovirus and enzyme-linked immunosorbent assay (ELISA) for rotavirus. Norovirus PCR-positive products were then sequenced and genotyped.

Results

Of 267 students enrolled, 144 (54%) met our case definition. Regression analysis revealed elevated risk associated with iced tea, which was made from tea powder mixed with hot water and self-made ice (risk ratio 1.54, 95% confidence interval 1.22–1.98). Ice used for beverages, water before and after water filter of the ice machine and 16 stool and vomitus samples from ill students were tested positive for norovirus; Multiple genotypes were identified including GI.2, GI.4 and GII.17. GII.17 was the predominant genotype and phylogenetic analyses showed that noroviruses identified in ice, water and human samples were clustered into the same genotypes. Environmental investigation revealed the ice was made by inadequate-filtered and un-boiled water.

Conclusions

We identified the ice made by norovirus-contaminated un-boiled water caused the outbreak and the predominant genotype was GII.17. Adequately filtered or boiled water should be strongly recommended for making ice to avoid possible contamination.

Ice-associated norovirus outbreak predominantly caused by GII.17 in Taiwan, 2015

BNC Public Health, 2017, 17:870, Hao-Yuan Cheng, Min-Nan Hung, Wan-Chin Chen, Yi-Chun Lo, Ying-Shih Su, Hsin-Yi Wei, Meng-Yu Chen, Yen-Chang Tuan, Hui-Chen Lin, Hsu-Yang Lin, Tsung-Yen Liu, Yu-Ying Wang, Fang-Tzy Wu https://doi.org/10.1186/s12889-017-4869-4

https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-017-4869-4

100 sickened: Why I hate text and always told students to check e-mail: Missed e-mail leads to Norovirus outbreak

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Back around 2002, when my lab and responsibilities were growing exponentially, the hardest thing to teach any new student was this: check your e-mail.

Every 5 minutes.

(It would have been every minute, but the IT nerds at the university said no one needs that, it can wait. Which is why they’re on university timelines.)

We were on-call for grocery stores, ran the national food safety hotline, and whether I was golfing or hanging with the kids, I was always accessible.

I hate text.

I hate Facebook.

Hate is a strong word, but apt in this situation.

Chapman says now, there’s a whole generation that missed e-mail.

But since I had it from the late 1980s, it was always crucial.

And still is.

Radio-Canada reports that an email miscommunication led to an outbreak of norovirus that affected more than 100 people at a long-term care facility in Rouyn-Noranda in early August.

Patients and staff at the home were served peach and raspberry compote on Aug. 2 and 4.

A few hours later, 26 people showed symptoms of gastroenteritis.

Over the next 10 days, between Aug. 4 and 14, 61 patients and 48 employees at the facility fell ill.

The Centre intégré de santé et de services sociaux (CISSS) in the Abitibi-Témiscamingue region had been notified that the raspberries were subject to a recall because they were suspected of being contaminated with norovirus.

The Canadian Food Inspection Agency emailed the facility about the recall on July 20, according to access to information requests obtained by Radio-Canada.

But that email was only sent to one person and that person didn’t relay the information to the kitchen staff.

The facility wouldn’t say why the message didn’t get to the kitchen.

The interim head of IT services for the facility, Stéphane Lachapelle, says more people have been added to its mailing list.

 

Rapid detection of human norovirus in frozen raspberries

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Raspberries have lately caused several human norovirus (HuNoV) outbreaks in Europe.

In this study, we developed and evaluated for HuNoV reverse transcription (RT)-PCR detection in frozen raspberries extraction methods that have equal sensitivity but are less time-consuming than widely used methods based on polyethylene glycol (PEG) precipitation and chloroform–butanol purification.

One method was applied to stored frozen raspberries linked to previous HuNoV outbreaks and berries on sale. In the virus elution-based Method 1, sparkling water eluted viruses most efficiently from the berries. Method 2, based on direct nucleic acid extraction with minor PEG supplement, yielded the highest number of positive findings (4 out of 9) at low virus concentration level of 100 genome copies HuNoV genogroup II per 25 g raspberries. Both methods showed approximately equal sensitivity to a method including PEG precipitation and chloroform–butanol purification. Two naturally contaminated berry samples linked to HuNoV outbreaks in 2006 and 2009 were still positive for HuNoV genogroup I, but all berry products purchased from a local store remained negative for HuNoV. In conclusion, this study presents two efficient and rapid methods which can be used in urgent HuNoV outbreak investigations, since the results of the virus analysis are available in a few hours.

Norovirus at the hotel California

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As I gracefully age, I realize a few truths: my brain can’t take any more hits to the head, my childhood buddy Wayne will always be a better hockey player than me, and the Eagles suck.

I had one of those grade 10 English teachers who made us analyze contemporary music lyrics as poetry so he and his beard could sleep while students offered daft analysis (and lesbian seagull played while we meditated).

Some kid did Hotel California and got an A. I did Led Zeppelin’s Kasmir because it went on forever and meant nothing.

I got a D.

Adam Racusin of 10 News reports a group of people in the health care industry are suing the world famous Hotel del Coronado.

A lawsuit filed last week claims nearly 90 people got sick after attending a dining event at the hotel.

According to the suit, several of the attendees were confirmed to have been infected with norovirus.

The suit claims “an investigation by the California Department of Public Health confirmed that the source of the norovirus outbreak was a dessert table containing food items that were prepared, served, and monitored by defendants in accordance with the contract between Defendants and Healthgrades.”

The dining event was part of a three-day symposium sponsored by Healthgrades, an online site for information about physicians and hospitals.

45 sick: Norovirus outbreak linked to Hawaiian restaurant

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One of Waikiki’s newest restaurants underwent a thorough cleaning after several diners got sick.

Herringbone Waikiki voluntarily closed Thursday after a string of illnesses was traced back to the restaurant.

A sign on the door read, “Unfortunately we will not open this evening and apologize for any inconvenience.”

The Hawaii Department of Health says it’s an outbreak of norovirus, which is a foodborne illness.

So far, up to 45 people have fallen ill, and officials say that number will rise.

According to a department report posted online, on Saturday, Oct. 7, at around 11:30 a.m, “three customers ordered and shared the toss salad. All three showed symptoms of nausea, vomiting, abdominal cramps and diarrhea.”

On Monday, diners who got sick called Herringbone and the health department.

An inspector was dispatched Tuesday and observed good personal hygiene practices. No employees were sick.

Texas Environmental Health Association and Austin

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There are exactly five cities I could live in. Portland, Madison, Toronto, Raleigh.

And Austin.

I grew up in one of these, and currently live in another.

The only problem with Austin is a lack of hockey. 

Today I gave a talk to the Texas Environmental Health Association about a bunch of food safety stuff. Got to catch up with old friends and tell folks about some of the fun things we’re working on.

Also got to eat some brisket, listen to good music and drink some Texas beer.

Good times.