Wash hands, sick (and non-sick?) workers stay home: 278 sickened in Norovirus outbreak at Shanghai boarding school, 2012

Researchers conclude in BMC Public Health that this Norovirus outbreak could be limited by good hygiene, daily disinfection and “excluding asymptomatic food handlers from food preparation.”

NorochickI’m not sure how that would work, but based on fecal swabs, nine were Norovirus-positive in asymptomatic food preparers.

Here’s the abstract:

More than 200 students and teachers at a boarding school in Shanghai developed acute gastroenteritis in December, 2012. The transmission mode remained largely unknown.
An immediate epidemiological investigation was conducted to identify it.

Methods: Using a retrospective cohort design, we investigated demographic characteristics, school environment, and previous contacts with people who had diarrhea and/or vomiting, drinking water conditions, recalls of food consumption in the school cafeteria, hand-washing habits and eating habits. Rectal swabs of the new cases and food handlers as well as water and food samples were collected to test potential bacteria and viruses. Norovirus was detected by real-time reverse transcription-polymerase chain reaction (RT-PCR).

Results: A total of 278 cases developed gastrointestinal symptoms in this outbreak, and the overall attack rate was 13.9%. The main symptoms included vomiting (50.0%), abdominal cramps (40.3%), nausea (27.0%), diarrhea (6.8%) and fever (6.8%).
Twenty rectal swab samples were detected as Norovirus-positive, including 11 from student cases and 9 from asymptomatic food handlers (non-cases). Among environmental surface samples from the kitchen, 8 samples were also detected as Norovirus-positive.
The genotypes of viral strains were the same (GII) in patients, asymptomatic food handlers and environmental surfaces. Other samples, including rectal swabs, water samples and food samples were negative for any bacteria and other tested viruses.
Asymptomatic food handlers may have contaminated the cooked food during the food preparation.

Conclusion: The study detected that the outbreak was caused by Norovirus and should be controlled by thorough disinfection and excluding asymptomatic food handlers from food preparation. Early identification of the predominant mode of transmission in this outbreak was necessary to prevent new cases.
Furthermore, good hygiene practices such as regular hand washing and efficient daily disinfection should be promoted to prevent such infection and outbreaks.

Author: Caoyi XueYifei FuWeiping ZhuYi FeiLinying ZhuHong ZhangLifeng PanHongmei XuYong WangWenqin WangQiao Sun

Credits/Source: BMC Public Health 2014, 14:1092

Arizona school’s noro outbreak linked to over 100 ill

I was chatting with a couple of guys at a birthday party of one of Sam’s friends this past weekend and relayed that I do food safety stuff. One dude said “I hate this time of year: between the colds, pink eye and norovirus our kids pick up at school we’ll all be sick until Thanksgiving.”

‘Tis the season for school-related infections.norovirus-2-1

According to AZ Central, the so-called winter vomiting virus is making an appearance in the desert. Over 10%, at least 100 students, of Kyrene de la Colina, a Phoenix (AZ) elementary school called in sick last Thursday – definitely an outbreak.

Kyrene Elementary School District spokeswoman Nancy Dudenhoefer said the absences were reported to the Maricopa County Health Department after more than 10 percent of students who attend the Ahwatukee Foothills school called in sick on Thursday.

The district also sent notices to parents about norovirus symptoms and advised them to keep ill children home from school.

In the Tempe Union High School District, Bruce Kipper, principal of nearby Mountain Pointe High, also notified parents about norovirus symptoms.

Kyrene hired a company that specializes in removing norovirus to clean Colina and its school buses before the Friday morning bell. Colina and all other Kyrene schools were open on Friday.

Maricopa County Health Department spokeswoman Jeanene Fowler said norovirus outbreaks are common in schools. “Norovirus is very common,” Fowler said. The solution is “cleaning and getting kids to stay home if they are sick.” (cleaning and sanitizing, with chlorine-based compounds -ben)

Stay at home, thoroughly clean: Pennyslvania hospital implements improvements after norovirus affects 19 staffers

Children’s Hospital of Philadelphia recently improved its virus-detection process after a state Health Department investigation revealed the room of a patient suffering from norovirus in April was inadequately cleaned amid an outbreak among nurses there.

vomit.toiletThe Health Department report was based on an investigation completed in May after 19 nursing staffers working in the same unit fell ill with norovirus – a highly contagious but generally nonlife-threatening gastrointestinal bug that causes vomiting and diarrhea.

The report found that the room of a patient suffering from the virus in the same unit on the weekend of April 5-6 had not been properly cleaned with bleach as required by the hospital’s infection-control policy. All but three of the affected staffers had developed symptoms between March 11 and March 23, before the inadequate cleaning, according to the report.

The report said hospital procedures also were not properly followed in early March when a patient’s mother displayed norovirus symptoms March 8 while visiting. “There was no documented evidence that [Infection Control] was notified of this incident,” the report said. Whether that patient room was adequately cleaned is unclear in the report.

The Health Department investigation also found that staffers who were out sick with norovirus were not instructed to follow hospital protocol of staying home until they were symptom-free for 48 hours until March 27 – after the majority of the affected staff already had been ill. Only three additional staffers fell ill after that date, the report said.

vomit.infosheet.oct.08

Commonwealth Games athletes’ village outbreak report released

In July over 80 staff and volunteers were hit with a touch of the norovirus prior to the Commonwealth Games (the Olympics, sort of, except the only nations invited are part of the British, uh, commonwealth). According to Herald Scotland, HS Greater Glasgow and Clyde released a report (unfortunately we can’t locate it to mine it for other gems) that states that the lack of (and inappropriate) cleaning and sanitation of a specific washroom was to blame – and so was using ineffective alcohol-based hand sanitizer instead of handwashing.2014_Commonwealth_Games_Logo.svg

Now identified as the very common but debilitating norovirus, the bug was first reported on July 15. The Games opened on July 23.

The report said: “This outbreak did not have serious public health consequences. However, due to the timing of the outbreak, there was a risk to the success of the Games if the virus spread beyond the security staff and cases were reported among athletes and team officials.

“Because of the association with the Commonwealth Games there was immense media and political interest.”

The report reveals “deficiencies of cleaning” at the Athletes’ Village. It said: “Some areas of the Village were not covered by any cleaning arrangements. These included the pedestrian screening area, general security areas and one block of toilets being used by security staff.”

It found staff were using the “wrong type of alcohol hand gel, which would not have been effective against norovirus” rather than washing with soap and water.

It also discovered three different cleaning firms contracted at the site were using different products, including quaternary ammonium compounds, which do not kill norovirus. Staff, the report found, did not know how to report something that needed cleaned up.

Eighty of the 83 cases were security staff. No athlete was affected. 

Environmental health officers, meanwhile, checked temporary toilet blocks and found they were substandard. The report said: “In many cases, there were no hand washing facilities with only non-gold standard hand gels being provided.”

Games organisers said their catering, cleaning and waste planning regime was “fully compliant with all relevant industry standards” and insisted they quickly teamed up with health officials to overcome the bug.

Missing a restroom on a list of sanitation stops, using incorrect sanitizers (like quats) in the middle of an outbreak and having only alcohol-based hand sanitizers (that apparently weren’t VF481) isn’t industry best practice.

EFSA: Scientific Opinion on the risk posed by Salmonella and Norovirus in tomatoes

Tomatoes may be minimally processed to obtain ready-to-eat products, and these steps include selection, washing, cleaning, stem removal, cutting, packaging and storage.

tomatoEpidemiological data from the EU have identified one salmonellosis outbreak and one Norovirus outbreak associated with tomato consumption between 2007 and 2012. Risk factors for tomato contamination by Salmonella and Norovirus were considered in the context of the whole food chain.

Available estimates of the Salmonella and Norovirus occurrence in tomatoes were evaluated together with mitigation options relating to prevention of contamination and the relevance of microbiological criteria. It was concluded that each farm environment represents a unique combination of risk factors that can influence occurrence and persistence of pathogens in tomato production.

Appropriate implementation of food safety management systems including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should be primary objectives of tomato producers. The current lack of data does not allow the proposal of a Hygiene Criterion for E. coli at primary production of tomatoes and it is also not possible to assess the suitability of an EU-wide E. coli Process Hygiene Criterion.

There are Food Safety Criteria for the absence of Salmonella in 25 g samples of ready-to-eat pre-cut tomatoes as well as in unpasteurised tomato juice placed on the market during their shelf life. A Food Safety Criterion for Salmonella in whole tomatoes could be considered as a tool to communicate to producers and processors that Salmonella should not be present in the product.

Testing of tomatoes for Salmonella could be limited to instances where other factors indicate breaches in GAP, GHP, GMP or HACCP programmes. It is currently not possible to provide a risk base for establishing a Norovirus Food Safety Criterion for these foods.

UK wedding party full of police officers struck down with Norovirus after pub serves food found to be ‘unfit for human consumption’

A wedding party with 80 guests - including 60 serving police officers – fell ill with norovirus after being served food ‘unfit for human consumption’.

norovirus-2The happy couple and the majority of their guests became unwell with the vomiting bug after eating vegetarian lasagne and fish pie during the reception at The Globe Inn at Frogmore, Devon.

Pub owners John Horsley, 64, and wife Lynda, 63, have been fined £10,000 for using dirty cleaning equipment and unclean food at the party.

They admitted three charges of breaching food hygiene laws at Torquay Magistrates Court and were fined £4,999 each. 

Environmental health inspectors found unacceptable levels of bacteria on a towel used for hand drying and a pot sponge after the party last year. 

The court heard how the couple failed to keep premises clean and have a proper system in place to check hygiene.

They were also found to have been unable to comply with food safety requirements. 

#Norovirus

Katie Overbey, an MS student studying food science at NC State writes,

The Internet is a hub for oversharing, and nothing seems to be off limits, including vomit.

Check out these Twitter hashtags from recent school outbreaks of norovirus: #RHSplagu, and #DSSplague2014. RHS is Richardson High School in Texas, where norovirus sickened about 600 people this past January. The second hashtag is from Delta Secondary School in Canada, where about 300 people came down with norovirus in June. Some common noro webthemes from these hashtags are updates on the progression of the virus, concerns about missing school, various plans for trying to not get sick and discussions about vomit. Don’t have your vomit fix? Do a search of #norovirus on Twitter and for even more fun try #vomit.

Besides providing hours of entertainment and the occasional cringe, why should people care about broadcasting their bodily functions for the world to see?

Researchers are demonstrating that the symptom-sharing provides a signal to aid in identifying outbreaks. All those seemingly TMI posts about people’s evenings spent on the toilet could actually be predicting norovirus outbreaks sooner than any lab test. New York City Health Department has been using Yelp reviews that mention food poisoning or norovirus to find outbreaks and gather more details about them. Chicago has a Twitter account, @foodbornechi, for people to tweet about their foodborne illnesses.

Last year, the U.K. Food Standards Agency (FSA) embarked on a social media listening project that, it hopes, has the potential to predict outbreaks of the winter vomiting bug, norovirus, earlier than ever before.

FSA’s social media team sifted through Twitter data from the last norovirus outbreak during the winter of 2012-13, hunting for spikes in certain related key words and phrases being used in tweets. They then compared the frequency of the key words to the number of lab reports of confirmed norovirus cases in the same period.

They found significant correlations between spikes in the number of lab reports and spikes in conversations on Twitter using words and hashtags such as #winterbug, #norovirus, sickness bug, winter virus and vomiting.

What’s more, they discovered a set of symptom keywords, such as #barf, #flu, chuck up, puke, retch and upset stomach, which strongly correlated to future lab cases.

FSA stated some caveats though, - People self-diagnose. Symptom keywords and search terms are broad so “there’s always going to be a bit of noise”. And early warnings of an outbreak will increase chatter around the subject and might skew the data.

Exploring the use of Twitter for disease detection is promising and could allow health officials to disseminate information earlier and potentially control the spread of norovirus.

Fast Facts about Cutting Boards and Food Safety in Your Kitchen (from The Abstract)

Channeling my inner Dean Cliver, I had a chat last week with my friend Matt Shipman about cutting boards and food safety. Matt, a science writer, public information officer at North Carolina State University, curator of The Abstract, and all around swell dude, writes:

Anything that touches your food can be a source of contamination and foodborne illness – including cutting boards.

For example, if you cut up a raw chicken, and then use the same cutting board to slice a tomato for your salad, you run the risk of cross-contamination – with bacteria from the chicken being transferred to the tomato. That, of course, would be bad.

And vegetarians aren’t off the hook either. Fruits and vegetables can also carry pathogens (and transfer them to cutting boards).

To reduce the risk of foodborne illness in your kitchen, here are some things you should know about cutting boards.

Plastic Versus Wood

For a long time, most (if not all) cutting boards were made of wood. But at some point people began using plastic cutting boards. The idea was that they were easier to clean (and sanitize), and therefore were safer.

But in the late 1980s, a UC Davis researcher named Dean Cliver – the de facto godfather of cutting board food safety – decided to investigate whether plastic cutting boards really were safer. Answer: not really.

Photo credit: Betsssssy, via Wikimedia Commons.

Plastic cutting boards, Cliver found, are easier to sanitize. But cutting on them also leaves lots of grooves where bacteria can hide. Wood is tougher to sanitize, but it’s also (often) tougher in general – you won’t find as many deep scratches in the surface.

In addition, researchers have discovered that the type of wood your cutting board is made from also makes a difference.

“Hardwoods, like maple, are fine-grained, and the capillary action of those grains pulls down fluid, trapping the bacteria – which are killed off as the board dries after cleaning,” says Ben Chapman, a food safety researcher at NC State. “Soft woods, like cypress, are less likely to dull the edge of your knife, but also pose a greater food safety risk,” Chapman explains. “That’s because they have larger grains, which allows the wood to split apart more easily, forming grooves where bacteria can thrive.”

Which type of cutting board should you use? Chapman recommends using plastic cutting boards for meat and wood cutting boards for fruit, vegetables, or any ready-to-eat foods (like bread or cheese).

Why use plastic cutting boards for meat? Because of how you wash them.

Cleaning Your Cutting Board

Plastic and wood have different characteristics, so you have to handle them differently.

Plastic cutting boards can be placed in the dishwasher, where they can be sanitized by washing at high temperatures. But wood cutting boards would quickly be ruined by a dishwasher, and not everyone owns a dishwasher. If you’re washing a cutting board by hand, you should:

  • Rinse the debris off the cutting board (being careful not to splatter contaminated water all over the place);
  • Scrub the cutting board with soap and water (to get out anything in the scratches or grooves on the board’s surface); and
  • Sanitize the cutting board (you should use different sanitizers for wood cutting boards than for plastic ones).

For plastic cutting boards, you should use a chlorine-based sanitizer, such as a solution of bleach and water (one tablespoon of bleach per gallon of water – has a shelf life of a week or two). But for wood cutting boards, you should use a quaternary ammonia sanitizer, such as a solution of Mr. Clean and water (follow the dilution instructions on the label).

“This is because chlorine binds very easily to organic materials, like the wood in a cutting board, which neutralizes its antibacterial properties,” Chapman says. “Quaternary ammonia is more effective at killing bacteria on wood or other organic surfaces.”

It’s worth noting that you should also sanitize your kitchen sponge/rag/brush after you’ve used it to scrub the chicken-juice off your cutting board – or else you run the risk of contaminating the next thing you wash (which is the exact opposite of what you’re trying to do).

The last step in cleaning your cutting board is an important one –dry it.

“Make sure you put the cutting board somewhere that air circulates, so that it can dry completely,” Chapman says. Bacteria need moisture to grow, and you don’t want to give them a welcoming environment.

“Historically, butchers used to put salt on their butcher blocks to keep them from smelling bad,” Chapman says. “This worked because the salt drew the moisture out of the wood and prevented bacterial contamination, which is what caused the smell – though the butchers didn’t know it at the time.”

When To Replace Your Cutting Board

At some point, scrubbing and sanitizing might not be enough. When your cutting board has accumulated a lot of deep grooves from repeated use, you probably need to replace it.

“The more grooves it has, and the bigger they are, the more area is available for trapping moisture and giving bacteria a place to proliferate,” Chapman says.

Norovirus chef Heston Blumenthal defends $500 price tag for Fat Duck Australia pop-up

Like I’ve written before, all the hacks are headed to Australia to make a buck (I actually live here, because of my wife’s career).

heston_blumenthalAging rock stars, actors, and celebrity chefs, they’ve all done, or are doing, the tour of Australia.

Norovirus-isn’t-my-fault chef Heston Blumenthal — whose famed Bray, England restaurant Fat Duck is popping up in Australia next year — has come under fire for the hefty price point of its tasting menu. The pop-up, which will take place in Melbourne, will cost $525 AUD ($475 USD) per person, excluding beverages. Not only is it more expensive (about $75 more) than the original price in England, but Good Food AU notes that this makes it one of Australia’s “most expensive restaurants.” Blumenthal believes the price is justified: “We’re basically picking up the entire kitchen and staff from the Fat Duck and relocating across the world.” Blumenthal must also house his 50 or so British staff for six months.

Careful with those raw oysters, which sickened 550 a couple of years ago in the UK.

He also added that “the cost structure for the Duck is like no other restaurant in the world. It can take one chef days just to make one item for the menu. Dining at the Duck is four and a half hours of entertainment.” In theory that’s just over $100 an hour for a “multi-sensory gastronomic journey of history, nostalgia, emotion and memory.” The reservation line opens October 8 and will close October 26. Fat Duck Australia will pop-up from February 3, 2015 to August 15, 2015.

I won’t be going.

Michigan Tough Mudder race organizers share info about avoiding illnesses

Over the past 6 months I’ve been running a few times a week as a way to get some decent exercise while I try to get to a more healthy weight.

Not an activity that I liked until I was about 30, I do most of my running on treadmills while I watch sports and listen to podcasts. There are a few guys on my hockey team who have taken up endurance mud running as a way to work off the chicken sandwiches and beer we consume every Monday night. A couple of them ran the Tough Mudder in South Carolina a couple of years ago and are trying to talk me into joining them in the spring. Not sure I’m into it.TMSplash

From the organizer’s website, “Tough Mudder events are hardcore 10-12 mile obstacle courses designed by British Special Forces to test your all around strength, stamina, mental grit, and camaraderie. Triathlons, marathons, and other lame-ass mud runs are more stressful than fun. Not Tough Mudder. As hardcore as our courses are, we meet you at the finish line with a beer, a laugh, and a rockin’ live band.”

The site lists a set of obstacles with names like Arctic Enema, Dirty Ballerina and Kiss of Mud.

The races have a history of testing more than physical and mental toughness – they have been linked to multiple pathogen outbreaks.

A 2012 Tough Mudder in Scotland was linked to at least three cases of E. coli O157.  Last year a Michigan event recent was linked to norovirus.

According to Mlive, the organizers of this weekend’s Michigan event are addressing pathogen concerns.

Tough Mudder officials want to remind anyone planning to compete or attend this year’s event to practice good hygiene before and after attending.

“Illnesses of this nature are extremely rare. More than 1.5 million Mudders have run a Tough Mudder course; this issue is highly isolated,” said Ben Johnson, a spokesperson for Tough Mudder, via email. “However, safety is our No. 1 priority, and we encourage all participants, spectators, and volunteers to take the following preventative measures:

- It is important to not attend the event if you are feeling ill. We can provide a transfer to a future event.

- Practice good hygiene before and after the event:

Stay home for at least 48 hours after symptoms disappear.

Use chlorine-bleach based household cleaners to disinfect contaminated surfaces.

Free transfers to a future event is a good step – maybe that will result in sick folks skipping it until they’re done shedding pathogens.