Why I don’t eat raw shellfish: Viruses in food

The UK Advisory Committee on the Microbiological Safety of Food (ACMSF) has published its extensive review of viruses in the food chain. The ACMSF set up a group to revisit the issue of foodborne viruses in light of developments in this area. The final report considered the most important viruses associated with foodborne infections – norovirus, hepatitis A, and hepatitis E.

heston_blumenthalThe report makes a number of recommendations for government departments, including the need for more research in certain areas, and for clear advice for consumers, for example on cooking shellfish and pork products and information on washing leafy green vegetables and soft fruit. The government will respond in due course when the recommendations have been considered in detail.

Professor Sarah O’Brien, Chair of the ACMSF, said: ‘Until recently it has been difficult to assess accurately the impact of foodborne viruses on public health. However, significant advances in our ability to detect viruses in food, coupled with up- to-date estimates of the burden of illness, highlighted in the ACMSF’s latest update, show us that viruses are very important, preventable causes of foodborne illness.’

Summary

In 1994, in response to the outcomes of a joint Advisory Committee of Microbiological Safety of Food (ACMSF) and Steering Group on the Microbiological Safety of Food (SGMSF) meeting, a Working Group was set up to investigate the science and epidemiology of Foodborne Viral Infections. The Working Group assessed the risk from viruses that were believed to be the primary cause of foodborne illness. This report provides an update to this information and provides a new focus on the viruses which are currently the major route of foodborne illness.

Since the publication of the 1998 report, with the exception of two minor risk assessments on hepatitis E and avian influenza, no formal review on viruses had been performed by the ACMSF. It was decided that as significant developments had been made not only in the detection of foodborne viruses, but also in the amount of information obtained from the Infectious Intestinal Disease (IID) Study in England (published in 2000), which indicated a significant disease burden from enteric viruses in the community, it was important that an Ad-Hoc Group was convened to revisit these issues and to provide an update to the 1998 risk assessment.

norovirus-2The FVI Group first met to begin their consideration in November 2010. Over 32 months, the Group met thirteen times to discuss all aspects of viruses in the food chain from farm to fork. As a starting point for the report, the Group reviewed the recommendations from the 1998 report and gave consideration as to whether these had been adequately addressed or were still relevant. At the same time the recommendations from the 2008 World Health Organisation (WHO) Viruses in Food: Scientific Advice to Support Risk Management Activities Matrix and CODEX Criteria, and the European Food Safety Authority (EFSA) Scientific Opinion on an update on the present knowledge on the occurrence and control of foodborne viruses were reviewed.

Using this information along with data on disease burden in the community and outbreak data (from IID and IID2) the Group agreed the scope of the report and what viruses would be its main focus. It was decided that that due to their potential impact and the paucity of data in this area, norovirus, hepatitis E and hepatitis A would be the main focus of the report, although many of the recommendations would also be applicable to other enteric viruses.

During its consideration, the Group reviewed available data on commodities contaminated at source, i.e. bivalve shellfish, pork products and fresh produce and reviewed data on risks associated with infected food handlers. Environmental contamination was reviewed with consideration given to testing methods such as polymerase chain reaction (PCR), person-to-person transmission and food handlers. The Group also considered the engagement with industry and other Government departments (OGDs) regarding environmental conditions of shellfish waters and its impact on norovirus.

A review of data on issues regarding food contact surface contamination, including survivability and persistence was considered along with options for control at all stages of the food chain e.g. thermal processing, storage etc. The thermal stability of hepatitis E was considered with data presented on the increasing occurrence of the disease particularly in older UK males and the recent case control study on the association with processed pork products.

In order to obtain sentinel data the group investigated the important issue of knowledge gathering and surveillance data regarding foodborne viruses. The current limitations of the data were discussed along with what type of data was needed to provide more useful/accurate information on foodborne virus outbreaks. This review included looking at outbreaks from an Environmental Health Officer (EHO) perspective and how they prioritise what they investigate and the data they collect.

Finally, the group reviewed the consumer perspective on risk. This included looking at how risk is presented and information distributed, as this was likely to impact on any future risk assessment.

Within the report the Group has endeavoured to prioritise the recommendations by separating these into those that will inform risk assessments and those that will impact on risk assessments. Full details are provided in the report; however, key recommendations include:

A better understanding of ‘’foodborne viral disease’ (Chapter 3) is required by investigating the correlation between infective dose and genome titre. Molecular diagnostics, typing and quantification should also be used to better understand the burden of virus contamination in foodstuffs. Work is also recommended to develop the methods used to assess norovirus and hepatitis E infectivity in food samples. This would better inform surveys and could potentially be applied to routine monitoring.

Improved ‘routine surveillance and investigation of foodborne viruses’ (Chapter 5) is required with Government agencies developing a single integrated outbreak reporting scheme. A joined up approach that would also involve the annual consolidation of records would reduce the chance of underreporting outbreaks. Further to this, reliable methods for norovirus whole genome sequencing should be developed to enable virus tracking and attribution.

More research on the ‘contamination of food’ (Chapter 6) through sewage contamination is recommended. In particular work should investigate the effectiveness of sewage treatment processes in reducing norovirus concentrations, including the use of depuration on shellfish species and disinfection treatments. Similarly, research is needed to identify the most effective means of decontaminating ‘fresh produce’ post-harvest (Chapter 7).

With the emerging risk of hepatitis E in pigs, the Group recommends work is undertaken to investigate the heat inactivation of hepatitis E in ‘pork products’ (Chapter 8). Research on the effect of curing and fermentation on hepatitis E in pork products is also recommended.

The full list of conclusions and recommendation are presented at the end of each subject area and are consolidated in Chapter 12 for ease of reference.

The assessments made and conclusions reached by the Group reflect evidence oral and written drawn from the scientific community, Government departments and Agencies, EFSA and the scientific literature. The Group’s full conclusions, identified data gaps and recommendations are brought together at the end of this report. The ACMSF accepts full responsibility for the final content of the report.

Uh oh: health officials investigating multiple hepatitis A cases in Napa; including two food handlers

Most of the hepatitis-A-in-restaurants events follow this formula: A food handler or a server shows symptoms, the virus is confirmed, health folks provide patrons with shots and hopefully no one else gets sick.

The story in Napa County is a bit different: According to the Napa Valley Register, five people, including two food handlers at restaurants are ill and it’s unclear whether this cluster is an outbreak or a coincidence.546b8ec85be23.image

The source of the infection is under investigation. This is the first time in more than five years that acute Hepatitis A infection has been confirmed in a Napa County resident, the county said.

Two cases involve employees of La Toque restaurant and BANK Café and Bar in The Westin Verasa Napa. The source of these infections is unknown and there are no known cases involving customers, the county said in a news release.

The other three cases have no known association with these locations or other public settings, the county said.

In a county news release, Ken Frank of LT Napa Partners, which owns and operates La Toque restaurant and BANK Café and Bar, said, “La Toque restaurant and BANK Café and Bar take the health of our guests very seriously. We have strict health standards in place, and we are cooperating fully with Napa County Public Health to identify the source of the virus.”

Don Shindle, general manager of The Westin Verasa Napa, said, “We continue to assist Napa County Public Health and are taking all appropriate measures to ensure the safety of our guests and associates. We are confident that Frank and his team are diligent in following their high standards and working closely with Napa County Public Health.”

 

 

The burden of foodborne illness: it’s kind of a big deal

Last week I gave a guest lecture to an undergraduate nutrition class at UNC-Chapel Hill on the burden of foodborne illness as sort of an introduction to how and why folks like small farmers, school garden managers, cafeteria staff address food safety.

In a lot of my talks I get looks of bewilderment when I throw up the details from Elaine Scallan (and lots of her colleagues) papers on the burden of foodborne illness. Same with when I show economic estimates from friend of barfblog and all-around-good-guy-with-hipster-glasses Mike Batz (and colleagues). Foodborne illness, is kind of a big deal (at least to us food safety nerds).

I’m collaborating with Matt Shipman, public information officer at NC State University and curator of The Abstract, on a set of food safety-related posts from other NCSU folks as we roll toward WHO’s World Health Day – which is focused this year on food safety.

Here’s the first post:21d2f2194e7eb6925dac5a428cc518d4398b850316887505b740e8bd0e8ffdd2

Food safety poses a global health problem. According to the World Health Organization, contaminated food can cause more than 200 diseases – and food- and water-borne diseases that cause diarrhea are estimated to kill two million people each year worldwide.

And food safety is not just someone else’s problem.

“Foodborne illnesses are a significant problem in the United States, with massive impacts on public health and the economy,” says Ben Chapman, a food safety expert and researcher at NC State. And the numbers back Chapman up.

According to a 2012 report from researchers at the Emerging Pathogens Institute, Resources For the Future, and the U.S. Department of Agriculture’s Economic Research Service, foodborne illness is estimated to cost the U.S. more than $14 billion annually. (The estimate takes into account factors such as medical costs and productivity losses.)

And a 2011 report from the U.S. Centers for Disease Control and Prevention (CDC) reported an estimated 9.4 million episodes of foodborne illness each year in the U.S. from known pathogens. An additional 38.4 million cases are estimated to come from unspecified or unknown pathogens. In total, foodborne illnesses are thought to contribute to 48 million illnesses annually – resulting in more than 128,000 hospitalizations and 3,000 deaths.

It is, in short, a big deal.

So what are these foodborne illnesses? And how much damage does each of them cause?

In advance of World Health Day, we wanted to explain a handful of the relevant pathogens implicated in foodborne illness.

Campylobacter: Campylobacteris a genus of bacteria, many of which can cause an illness called campylobacteriosis in humans, with symptoms including diarrhea and abdominal pain. People can contract campylobacteriosis from undercooked chicken, from cross-contamination via raw chicken, or from drinking unpasteurized milk.

According to the 2012 paper, campylobacteriosis affects 845,000 people annually in the U.S., costing the nation an estimated $1.747 billion every year and leading to 8,463 hospitalizations.

Listeria monocytogenes: This is a bacterium that causes listeriosis, which is characterized by fever, muscle aches, and sometimes by gastrointestinal problems, such as diarrhea. Listeriosis can be contracted from an incredibly broad range of foods.

According to the 2012 study, listeriosis costs the U.S. $2.577 billion annually, despite the fact that there are only 1,591 illnesses per year. But 1,455 of those illnesses require hospitalization – and 255 result in death.

Norovirus: Noroviruses are the most common cause of foodborne illness in the U.S., affecting an estimated 19-21 million people each year. Symptoms range from vomiting and diarrhea to fever and headache. Transmission comes from ingesting infected feces or vomit particles – for example, by touching a contaminated surface and then touching food or touching your mouth.

According to the 2012 study, noroviruses cost the U.S. $2 billion per year, with more than 14,000 hospitalizations and approximately 150 deaths annually. NC State is a leader in norovirus research, and home to NoroCORE – the Norovirus Collaborative for Outreach, Research, and Education. NoroCORE pulls together norovirus research from 18 institutions, with funding from the U.S. Department of Agriculture.

Salmonella enterica: This is one species of the pathogen that has myriad of subspecies and types – more than 1,400 of which are known to cause human illness. Infection with Salmonella species causes salmonellosis, with symptoms including diarrhea, fever, and cramping. Salmonellosis can be contracted from a variety of sources, ranging from poultry to peanut butter to mangoes.

According to the 2012 study, the subspecies within S. entericaalone costs the U.S. $3.3 billion each year, causing more than one million hospitalizations and almost 400 deaths annually.

What are researchers doing about this?

The four pathogens listed above are just a few of the rogue’s gallery of bacteria and viruses that can cause foodborne illness. But researchers are constantly learning more about these health risks.

“New technology and new research on pathogens, practices and prevention are improving our ability to identify and address foodborne illness,” Chapman says. “The field is really opening up. It’s an exciting time to be involved in food safety research.”

Between now and April 7, we’re planning to publish a series of posts on various aspects of food safety – what we know, what we don’t know, and what we’re working on. We also hope to offer insights to help folks lower the risk of contracting foodborne illnesses. We hope you’ll learn something new.

Note: you can find all of our posts related to food safety here.

Citations:

Batz, Michael B., Sandra Hoffmann, and J. Glenn Morris, Jr. “Ranking the Disease Burden of 14 Pathogens in Food Sources in the United States Using Attribution Data from Outbreak Investigations and Expert Elicitation” Journal of Food Protection, Vol. 75, No. 7, 2012, Pages 1278–1291. doi:10.4315/0362-028X.JFP-11-418

Scallan, Elaine, et al. “Foodborne Illness Acquired in the United States—Major Pathogens” Emerg Infect Dis, Vol. 17, No. 1, 2011. doi:10.3201/eid1701.P11101

BC grocery cashier has hepatitis A (and may have handled some produce)

Nanaimo isn’t just known for its bars anymore (the holiday dessert kind, below exactly as shown).

A cashier at a Nanaimo, British Columbia (that’s in Canada) Superstore has been diagnosed with hepatitis A and according to CTV, may have exposed hundreds of shoppers to the virus. Folks who shopped at the store and used the cashiers for check out specific read-to-eat foods that might have been touched with bare hands are urged to attend a clinic for a shot.Nanaimo-Bars-570x380

Did you consume raw produce or unwrapped food during these following dates and times and go through a cashier? (Not self-checkout):

- February 25 late afternoon and evening
- February 26 afternoon and evening
- February 27 late afternoon and evening
- March 1 all day
- March 4 evening

There will be a drop-in clinic tomorrow, Saturday March 7 from 10am to 3pm at the Beban Park Social Centre on 2300 Bowen Rd.  Dates and times for additional clinics have not yet been set but you can follow online for the latest details.

This warning does not apply to products from any Superstore other than the one at 6435 Metral Drive.

Being specific with the messages about unwrapped foods and produce is a good move. Having handwashing tools close by a cashier is a good idea too.

Food Safety Talk 73: I Wish They’d Wash Their Hands More

Food Safety Talk, a bi-weekly podcast for food safety nerds, by food safety nerds. The podcast is hosted by Ben Chapman and barfblog contributor Don Schaffner, Extension Specialist in Food Science and Professor at Rutgers University. Every two weeks or so, Ben and Don get together virtually and talk for about an hour.  They talk about what’s on their minds or in the news regarding food safety, and popular culture. They strive to be relevant, funny and informative — sometimes they succeed. You can download the audio recordings right from the website, or subscribe using iTunes.Handwashing-Words-In-Shape-Of-Hand

This show starts with Don and Ben talking about the number-six item on their list of things to discuss for the episode:  Yosemite and how beautiful it is; Ben rates it at three thermometers, a rating system they invented.  Ben’s favorite thermometer is the Comark PDT300, even though someone sent him a ThermoWorks Thermapen which is Don’s favorite. Ben’s hockey team has been using thermometers when the grill sausages, this is what Ben’s contribution to the grill-outs.  Ben gets chirped for being the guy who brings the thermometer to the hockey grill. Ben is now supplying thermometers to other hockey guys.

Don talks about his lunch date with a podcast celebrity from the 5by5 network. Don tells the whole story about flying business class from Brazil to Texas then while in Texas, buying comic books and having lunch with Dan Benjamin.  Dan asked Don lots of food safety questions; they didn’t talk much about 5by5.  After this, Don attended the NoroCORE Food Virology meeting with Ben (the guys talked in real life, not just over Skype).

The conversation then turns to food safety culture and what that really means as it is in the literature.  Ben talks about a conversation he had about food safety culture with a person trying to develop a presentation on food safety culture for farmers. Don shares an email from Doug about food safety concerns at [insert big company name] that shared a Dropbox video of text and images displaying poor food safety. The guys then talk about the difficulties of creating a food safety culture when no one thinks it’s important. Ben talks about the many things that must be in place before a food safety culture can begin to be established.

Then conversation then transitions to how to talk about food safety risks. Ben suggests talking about risks frankly. The guys then discuss the uncertainties around risks and how to discuss them.  Discussing how quantitative risk assessments are performed and applied, and the issue of uncertainty messages, also come up in conversation.  Salmonella Hypetheticum then comes up in the conversation.

Don then brings up a book that he has been reviewing about food waste.  The same food waste topic has been featured on a television show that Don’s real life friend Randy Worobo was a guest on.  The issue of food waste and risk is discussed, with a focus on lower income persons and how to manage the need to save money against food safety risk decisions.  The use of fruits and vegetables that are past their optimum date to make infused vodka brings back memories of pruno-associated C. botulinum outbreaks.  Ben appreciates Don for working the math around food safety questions and the time and effort it takes to accurately answer without just ‘no don’t do that thing’.

Ben then brings up the issue of thawing a turkey on the counter the risks associated with that action.  Doug Powell has a paper in the Canadian Journal of Dietetics Practice Research about the calculations around thawing a turkey at room temperature.  Actually, it is ok to thaw a turkey at room temperature if you are within certain parameters.  This topic follows along with the possible Food Safety Talk tag line:  and it’s messy.

Next, Ben wants to talk about communication, but Don talks about the decision to eat fresh produce in Brazil, and other’s decision not to eat the fresh produce while visiting.  While at meetings Ben seems to focus on following the news and typing up Barfblog posts (some people are ok with that and will resist complaining; Ben does type rather loudly).  When Ben gets really into what he is writing, he lets out really loud sighs others have noticed, but Ben hasn’t noticed his inappropriate sighing.

Transitioning back to communication, Ben brings up a hepatitis A outbreak reported in Cumberland County Maine, but without a retail location identified. The State of Maine is taking some flack (could we call this chirping, see above) for their handling of this incident; the State of Maine tried to explain that this is because of a lack of personnel with specific expertise.  Maine has been in the news for other public health issues… a nurse breached a quarantine for Ebola by going for a bike ride.  Don suggests the public health system in Maine may be broken, Ben suggests this may be due to their having just eleven health inspectors for the whole state.

In the After Dark session, Ben reveals the most popular Food Safety Talk episode.  The guys aren’t sure which episode they just completed, 74?, 75?, whatever it takes.  Speaking of documentaries, Don recommends Jodorowsky’s Dune a documentary about a movie that was never made.

New Food Safety Infosheet: Hepatitis A illnesses linked to frozen berries in Australia

Australian public health officials have identified an outbreak of hepatitis A and linked illnesses to consuming Nanna’s frozen berries sold by Patties Foods.

Food safety infosheet highlights:

–  Health officials have confirmed 20 illnesses to date.

– The berries were produced by Patties Foods, which has issued a recall on three products.Screen Shot 2015-02-27 at 9.13.39 PM

– Officials expect cases to increase as the incubation period of the virus ranges from 15-50 days and those who are infected may not yet be showing symptoms.

Click here to download the food safety infosheet.

Food purchases remain faith-based, at market or megalomart: 4 sick with scombroid from tuna in Sydney

As the buy-local mantra becomes indoctrinated in Australia with 18 confirmed sick with hepatitis A from frozen Chinese berries, a Sydney café has vowed to change suppliers after four were sickened with scombroid poisoning linked to tuna from Thailand.

No country is an island, even Australia.

Going public: Signs of Australian hepatitis A outbreak linked to frozen berries month before public disclosure

Australian health types should be further embarrassed by their lack of disclosure, public notification and political pandering after it was revealed today that the first case of hepatitis A linked to frozen berries was diagnosed on January 3 but it took more than a month to recall the berries from supermarkets.

266570-ed20eaa0-b5e3-11e4-89a7-658c9eaa89c0Senate Estimates has been told there were three cases of Hepatitis A diagnosed in Victoria between January 3 and February 6.

Experts investigated to find a common link between the affected patients and identified the common factor as Nanna’s 1kg frozen mixed berries.

This meant it was not until February 12 that Ausfoodnet Victoria informed a national network of food regulators of the three cases.

It then took another two days before food company Patties announced a voluntary recall of the berries from supermarket shelves on February 14.

It was not until February 17 the government set up a national incident room to deal with the outbreak which has now spread to 18 people.

Australia’s Chief Medical Officer Professor Chris Baggoley said before the incident room was set up, epidemiologists and other experts in food safety were already working on containing the Hepatitis outbreak.

Uh-huh.

To the importer who says there’s no proven link, I say, epidemiology still works: 18 confirmed sick with hep A from frozen Chinese berries

As the number of confirmed hepatitis A cases in Australia from frozen berries grown in China rose to 18 over the weekend, as political rhetoric about imports and local food reached staggering new heights, the company continued to insist there’s no firm link between a national hepatitis A outbreak and its recalled berries.

epidemiology.WATER PUMP3_Page_4The company says its imported Chinese berries were recalled on health department advice despite a lack of proof from accredited laboratories of a link to the hepatitis A virus (HAV).

“At this point, we have not been provided any remaining consumer product to test from the 13 confirmed HAV cases to clinically verify there is indeed a link with the Nanna’s Mixed Berries,” managing director and chief executive Stephen Chaur said in a statement on Friday.

Mr Chaur said the company had rigorous testing that went beyond the Australian standards requirement that five per cent of imported fruit containers be tested.

“Patties Foods’ documented test regime is among the highest, testing 20 per cent of all the containers when they arrive in Australia,” he said.

But Mr Chaur said sample testing for microbial and viral markers had been increased to 100 per cent of imported frozen berries from all countries.

The company has checked quality control testing documents back to June 2014 and says they’re satisfied no biological indicators outside Australian guidelines have been detected.

Great. Prove it and make the data public.

Hepatitis A vaccines work: Michigan, 2013

Hepatitis A virus (HAV) infections among persons with developmental disabilities living in institutions were common in the past, but with improvements in care and fewer persons institutionalized, the number of HAV infections has declined in these institutions. However, residents in institutions are still vulnerable if they have not been vaccinated.

hepatitis.AOn April 24, 2013, a resident of a group home (GH) for adults with disabilities in southeast Michigan (GH-A) was diagnosed with hepatitis A and died 2 days later of fulminant liver failure. Four weeks later, a second GH-A resident was diagnosed with hepatitis A. None of the GH-A residents or staff had been vaccinated against hepatitis A. Over the next 3 months, six more cases of hepatitis A were diagnosed in residents in four other Michigan GHs. Three local health departments were involved in case investigation and management, including administration of postexposure prophylaxis (PEP). Serum specimens from seven cases were found to have an identical strain of HAV genotype 1A.

This report describes the outbreak investigation, the challenges of timely delivery of PEP for hepatitis A, and the need for preexposure vaccination against hepatitis A for adults living or working in GHs for the disabled.

CDC MMWR 64(06);148-152

Susan R. Bohm, Keira Wickliffe Berger, Pamela B. Hackert, Richard Renas, Suzanne Brunette, Nicole Parker, Carolyn Padro, Anne Hocking, Mary Hedemark, Renai Edwards, Russell L. Bush, Yury Khudyakov, Noele P. Nelson, Eyasu H. Teshale

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6406a4.htm?s_cid=mm6406a4_x