It’s cruise season and that means it’s norovirus season for vacationers who opt for trips on the high seas.

The most recently reported outbreak of the highly contagious virus, which often starts as a foodborne situation, was on P&O Cruises ship the Arcadia. People were sick during the voyage which ran from Dec. 29, 2022, through Jan. 3, according to the Centers for Disease Control and Prevention.

The outbreak sickened at least 84 passengers on board the Arcadia, with additional illnesses likely among people who did not seek treatment. Ten members of the crew were sickened in the outbreak. People exposed to the virus late in the voyage could have started exhibiting symptoms after disembarking.

“The gastrointestinal illness cases reported are totals for the entire voyage and do not represent the number of active (symptomatic) gastrointestinal cases at any given port of call or at disembarkation,” according to the CDC.

Norovirus symptoms include severe vomiting and diarrhea that usually begins within 48 hours of exposure to the virus. Symptoms usually last two to three days. Some patients require treatment for dehydration.

In response to the outbreak the cruise line and crew on board the ship took the following action:

  • Increased cleaning and disinfection procedures according to the ship’s outbreak prevention and response plan
  • Collected stool specimens from passenger and/or crew gastrointestinal illness cases
  • Notified embarking guests of the situation onboard and encouraged illness reporting and good hand hygiene.

The CDC’s Vessel Sanitation Program staff is monitoring the ship’s response to the the outbreak and reviewing the sanitation procedures for the current voyage. From 2006 through 2019 — the most recent year for which complete statistics are available — passengers sailed on 252 cruise ships in the Vessel Sanitation Program’s (VSP) jurisdiction. The rate of acute gastro illness on cruise ships decreased during 2006-2019 for passengers and crew.

Cruise ships are particularly susceptible for norovirus outbreaks because of the close quarters for large numbers of people, according to the CDC.

“Norovirus is a very contagious virus. You can get norovirus from an infected person, from contaminated food or water, or by touching contaminated surfaces,” according to the CDC. 

The virus is particularly difficult to eradicate and can live on surfaces — including doorknobs, counters and other frequently touched surfaces — for long periods of time. It can also be transmitted via droplets in the air spread during vomiting.

Learn how passengers can protect themselves with these tips for healthy cruising.

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The source of a norovirus outbreak that affected more than 200 people in an Australian state was likely an ill food handler, according to researchers.

In November 2021, the Australian Capital Territory Department of Health (ACT Health) was told by the owner of a food outlet about a report of illness among 11 people following the consumption of donuts. The bakery primarily sold donuts made onsite.

Donuts were a novel vehicle for foodborne illness in Australia, according to the study in Communicable Diseases Intelligence.

ACT Health also received two reports of illness on the same day related to the same bakery. Interviews with patients and their contacts found they had all eaten donuts from the shop 24 to 48 hours before becoming unwell. Orders were from walk-in customers, pre-booked requests or third-party food delivery applications, and no public alerts were issued by ACT Health.

True extent of outbreak unknown
A total of 301 people were interviewed or surveyed as part of the outbreak; 215 met the case definition. A further 16 people reported milder illness and did not meet the definition. It was one of the largest foodborne outbreaks ever investigated in the ACT.

The median age of respondents was 33 with a range of 3 to 91 years old and 159 were female. The median incubation period for ill people was 34 hours but this ranged from 9 to 112 hours.

The most common symptoms were diarrhea; vomiting; nausea and abdominal pain. Eight cases reported the presence of blood in stool and two people were hospitalized. All interviewed patrons ate food purchased from the premises between Nov. 20 and 24, 2021.

Eight cases had an incubation period of 96 hours or more. All these patients had at least one other member of their household who was a case and had earlier illness onset. They were likely infected by secondary transmission, rather than from a food source, said scientists.

Eight of 11 specimens collected from ill individuals were positive for norovirus. Food handlers at the shop did not provide stool specimens for testing.

Link to filled donuts but no flavor identified
A patient-control study included a group of 140 people at a catered function. A total of 192 donuts were prepared on the day. Overall, 59 people did the questionnaire, and 27 met the case definition. Eating any kind of filled donut was associated with becoming ill but no single flavor was identified as the source of infection.

An inspection at the bakery in late November found compliance with storage times could not be confirmed, because date labels were missing from some containers.

No pathogens were detected in the six food samples or 17 environmental swabs. However, no viral testing was done on samples as the ACT Government Analytical Laboratory (ACTGAL) is not able to test for viral pathogens.

The proprietor said staff was not ill during the study period and there were no records of vomiting or diarrhea among employees or customers. Order records were disposed of after being completed.

Two food samples showed results above detectable limits for coliforms; both were fillings made at the premises. Filled donuts required close handling of each one after cooking.

The source of contamination was not confirmed but it is suspected that a food handler worked while infectious and contaminated donuts. The scale of illness also suggests there was a lapse in hand hygiene and proper food handling procedures. Findings highlight the importance of excluding food handlers from work while ill-said researchers.

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An investigation into a norovirus outbreak among patrons of an Illinois restaurant has ended after identifying 173 people who became ill.

The McHenry County Department of Health began the investigation into D.C. Cobb’s restaurant after a cluster of illnesses was linked to the business beginning in late August and running through mid-September.

Norovirus was identified as the pathogen, but the investigation could not determine exactly how it was introduced into the facility. However, five employees were found to have been ill. A complete report of the investigation is available in Communicable Diseases Data and Reports under Foodborne and Waterborne Illness Reports.

“The case-control study conducted by MCDH identified 173 ill individuals, 168 patrons who experienced vomiting and/or diarrhea after eating food from D.C. Cobb’s from Aug. 29, 2022, through Sept. 16, 2022, and five staff who experienced vomiting and/or diarrhea before or after working at D.C. Cobb’s McHenry from Aug. 29, 2022, through Sept. 19, 2022,” according to the report.

“A case-control study identifies a sample of ill individuals during a specific timeframe and does not necessarily identify all individuals who became ill. The total number of ill individuals identified via this case-control study may therefore underreport the total number of ill individuals associated with this cluster of illness.”

A food item analysis identified that people were approximately 2.2, 3.5, or 2.7 times more likely to be ill after eating salad, the southwest chicken wrap, or the fried pickles with Cobb’s southwest sauce, respectively. Three other dishes were found to be associated with illness, although they are not as strongly implicated as a cause of illness: Cobb’s nachos, dynamite shrimp, and vampire tacos with bacon. Additionally, the food item analysis identified that people were approximately 2.4 or 3.3 times more likely to be ill after eating lettuce or green onion, respectively. Taken together, the analyses for dishes and ingredients indicate multiple dishes and ingredients were associated with illness.

“Norovirus is highly infectious and is easily spread person to person and on surfaces that have not been properly cleaned and sanitized. At least five employees were confirmed, through the employee survey, to have worked at the food establishment during their infectious period after being ill with Norovirus symptoms consistent with the case definition for this outbreak. These employees returned to work within 24 hours after their symptoms subsided. Food handlers are required to be excluded from work a minimum of 48 hours after being symptomatic and must be educated about good hand hygiene,” according to the health department report.

The Division of Environmental Health identified multiple breakdowns in critical operational procedures that created an environment where norovirus could remain viable and be readily transferred from food handlers to surfaces, surfaces to food items or patrons, and food handlers to food items – all of which could result in illness spreading to patrons. The most significant of these operational deficiencies are as follows:

1. Failure to provide hot water at a minimum temperature of 100 degrees Fahrenheit at the kitchen food service hand sinks.

2. Food preparation taking place where there was no access to a food service hand sink

3. Improper hand washing procedures and washing of hands at sinks that are not designated

as food service hand sinks

4. Failure to provide paper towels at one of the food service hand sinks

5. Failure of a food handler to wear food service gloves to cover artificial fingernails

6. Failure to provide a procedure for reporting/correcting a lack of tempered water and/or

lack of soap and paper towels at a food service hand sink

7. Approximately 30 percent of employees indicated that there is no monitoring of handwashing practices by management.

8. Failure of food service employees to recognize that their responsibilities include the

handling and/or service of ready-to-eat foods. Ready-to-eat foods require additional hand

washing procedures and barriers to prevent the transfer of contaminants to food items.

9. Multiple employees indicated that handwashing takes place either in the bathroom or at a

sink that is not designated for hand washing purposes only.

10. Failure to provide information regarding handwashing at appropriate stages in the food

preparation/food handling processes during the product flow evaluations.

11. While the correct minimum internal cooking temperatures were provided by interviewed

staff, no detailed information was provided regarding who/how the internal temperature of the food product is actually verified. Prep staff appears to utilize cooking time as the primary control.

12. Soiled food contact surfaces.

13. Chemical dish machine not reaching the minimum sanitizer concentration to sanitize

dishware.

14. Failure to provide test kits to ensure that sanitizer levels are at effective and safe levels.

After MCDH staff conducted an inspection and provided corrective action, D.C. Cobb’s employees and management responded quickly, reducing the transmission of illness associated with the outbreak, according to health officials.

“The management of D.C. Cobb’s fully cooperated with the illness investigation team and continues to work with Division of Environmental Health staff to implement additional strategies to prevent future public health concerns,” said Patti Nomm, MCDH’s Director of Environmental Health.

Norovirus is a highly contagious virus that spreads quickly from person to person or through contaminated items, and it cannot be treated with antibiotics. Symptoms of norovirus include diarrhea, vomiting, nausea, and stomach pain that usually last between 24 hours and 48 hours. Anyone with norovirus illness should stay home when sick and for 24 hours after experiencing vomiting or diarrhea.

Routinely cleaning and sanitizing kitchen utensils, counters and surfaces before preparing food can reduce the risk of norovirus. Good hygiene practices are equally important whether or not food is being prepared.

Scientists have assessed the use of next-generation sequencing (NGS) methods for norovirus in shellfish.

They found such techniques are ready to substitute current methods despite some limitations.

Bivalve molluscan shellfish (BMS) contamination with norovirus is a significant public health risk. Contaminated foods, such as oysters, may harbor concentrations of viral genomes and a large diversity of sequences when contaminated by human sewage.

“Based on results presented here, it is clear that too many European shellfish samples are exposed to sewage pollution as evidenced by the multiple sequences detected in shellfish samples, highlighting that we still need to enhance coastal water quality,” said researchers.

Using laboratory‐prepared samples of known norovirus composition, scientists evaluated the sensitivity, reproducibility, repeatability, and selectivity of metabarcoding, capture‐based metagenomics, and long amplicon sequencing. 

The three methods allowed sequencing of norovirus in most tested samples, however, performance in retrieving the expected diversity differed. Experts also compared the advantages and disadvantages of each method, the cost per sample and of equipment, the time for results, and whether they were suitable for surveillance or outbreak sequencing.

The consortium of the Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer), Centre for Environment, Fisheries and Aquaculture Science (Cefas), Technical University of Denmark (DTU), and Erasmus University Medical Center focused on norovirus-contaminated oyster samples. Findings were published by the European Food Safety Authority (EFSA).

Method potential and issues
Metabarcoding with separate amplification of polymerase and capsid gene segments followed by Illumina sequencing was the most sensitive method. However, due to the amplification steps and high sensitivity of NGS, the methods are prone to contamination and false positive results.

Work covered norovirus in shellfish and patient samples, from routine monitoring and surveillance and a survey of contamination in oysters in the European Economic Area from November 2016 to December 2018.

There were two artificially created sample sets, 212 oyster samples from the survey, pairs of human and shellfish samples from 16 foodborne outbreaks in France and Denmark from 2012 to 2019, and human norovirus sequences submitted to the global surveillance network Noronet.

One metabarcoding approach used Illumina technology and the other is based on long amplicon sequencing with Oxford Nanopore technology. Metabarcoding is highly sensitive and allows better capture of the diversity of noroviruses present in shellfish.

Experts said metabarcoding seems to be the more reliable method, with high sensitivity and reproducibility, and is easy to use for sequence analysis.

Other methods such as metagenomics show promise, but require further improvements regarding sensitivity. Metagenomic sequencing is sensitive enough to investigate the human outbreak samples but not those from shellfish. The VirCapSeQ metagenomics method requires optimization and should be used on samples with high levels of contamination or that was collected recently.

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A new way of detecting deadly Listeria contamination in food and a vaccine for troublesome Norovirus are being reported by major research universities.

University of Georgia College of Engineering researchers report they have a new method for Listeria detection, and the Virginia-Maryland College of Veterinary Medicine at Virginia Tech announced it will evaluate a potential live oral vaccine for norovirus, which is the No. 1 cause of foodborne illness.

Listeriosis, an infection caused by eating food contaminated by the bacterium Listeria monocytogenes, is known for causing severe illness in children, pregnant women, newborns, the elderly, and people with compromised immune systems.

It is the third leading cause of death from foodborne illness, or food poisoning, in the United States. An estimated 1,600 people get sick each year and about 260 die, according to the Centers for Disease Control and Prevention (CDC).

At present, Listeria contamination in food products is identified only through molecular tests conducted in diagnostic laboratories on samples taken at specific control points during the manufacturing and distribution process.

Although very accurate, this method requires significant processing time, transportation of samples, and expensive skilled labor and equipment.

In a new study published in the Journal of The Electrochemical Society, UGA researchers introduce a rapid diagnostic method based on electrochemical biosensing principles.

Electrochemical biosensors are promising alternatives to molecular detection methods because of their ease of use, high specificity, sensitivity, and low cost, according to the researchers.

The UGA researchers use bacteriophages, viruses that infect and replicate within bacteria, as receptors to identify Listeria monocytogenes using an electrochemical sensor.

Meanwhile, Lijuan Yuan, professor of virology and immunology at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, announced the progress being made around a norovirus vaccine. It was developed by Indiana University’s John Patton and colleagues using the Rotarix rotavirus vaccine as a platform.

Using reverse genetics, they will insert a norovirus protein into Gene 7 of the rotavirus. The virus will then express the norovirus protein in the gut, inducing an immune response against norovirus.

Yuan’s Virginia Tech lab will evaluate the replication capacity, immunogenicity, and protective efficacy of the vaccine using gnotobiotic pig models of human rotavirus and norovirus infection and diarrhea. A gnotobiotic animal is one that has been specially raised to contain zero germs or bacteria so researchers can better study the effects of bacteria and viruses such as rotavirus and norovirus.

The CDC says norovirus as the leading cause of vomiting and diarrhea from acute gastroenteritis in the United States, resulting in 19 million to 21 million illnesses every year.

Norovirus tends to affect young children and the elderly the most. It’s responsible for about 24,000 hospitalizations and 925,000 outpatient visits for American children each year, according to the National Center for Biotechnology Information. Rotavirus also causes acute gastroenteritis and hits young children the hardest.

“Together, rotavirus and norovirus cause over 415,000 deaths every year, and norovirus also has a very significant burden even in the countries that don’t have a lot of deaths. The economic cost is huge, with $4.2 billion in direct costs and $60 billion in indirect societal costs. You hear about norovirus outbreaks on the news all the time in hospitals, nursing homes, and cruise ships and how it’s closing down restaurants, so it’s got a lot of economic implications,” said Yuan.

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Virginia Tech researchers are testing a potential live oral vaccine for norovirus. The vaccine that the team is testing is in development by Indiana University researchers and uses the Rotarix rotavirus vaccine as a platform.

Norovirus is a contagious virus that causes vomiting and diarrhea. According to the Center for Disease Control and Prevention, each year, on average in the United States, norovirus causes 900 deaths, 109,000 hospitalizations, 465,000 emergency department visits and 19 to 21 million cases of vomiting and diarrhea illnesses.

“You hear about norovirus outbreaks on the news all the time in hospitals, nursing homes, and cruise ships and how it’s closing down restaurants, so it’s got a lot of economic implications,” said Lijuan Yuan, professor of virology and immunology at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, who is leading the testing of the vaccine.

Yuan’s lab plans to evaluate the replication capacity, immunogenicity, and protective efficacy of the vaccine. They will be using gnotobiotic pig models of human rotavirus and norovirus infection and diarrhea.

“We will use a gnotobiotic pig model of human norovirus infection and diarrhea. It’s actually the only laboratory animal model available that develops norovirus gastroenteritis that are similar to what you see in humans,” said Yuan.

In their coverage of Yuan’s research, VTx news explains that a gnotobiotic animal is one that has been specially raised to contain zero germs or bacteria so researchers can better study the effects of bacteria and viruses such as rotavirus and norovirus.  

Unlike many other viruses, norovirus cannot be cultivated efficiently in cell cultures. An added challenge is testing vaccines with animal models. For example, mice get murine noroviruses, which do not cause the same disease as noroviruses in humans.  

The pig model is a unique one, as there are fewer than 10 gnotobiotic pig facilities in the country.

Yuan and her lab study gnotobiotic pig models of human intestinal virus infection and disease, including how probiotics affect immunity and the evaluation of rotavirus and norovirus vaccines and anti-norovirus biologicals.  

The pig model of norovirus will test a vaccine that has the possibility of helping millions of people.

For more on Yuan’s research, read Sarah Boudreau’s story on VTx news site.

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Angelo’s Italian Market Inc. is recalling Gelato Artigianale al gusto di Raspberry Gelatois from the marketplace because of possible norovirus contamination of the raspberries used in this product.

This recall was triggered by Canadian Food Inspection Agency test results.

The recalled product has been sold at Angelo’s Italian Market Inc. in London, Ontario.

Recalled product:

BrandProductSizeUPCCodes
NoneGelato Artigianale al gusto di Raspberry Gelato1 L0 000000 067430None – Sold at Angelo’s Italian Market Inc., 755 Wonderland Road North, London, ON up to and including June 14, 2022

As of the posting of this recall, there have been no reported illnesses associated with the consumption of this product.

Recalled products should be thrown out or returned to the location where they were purchased

About norovirus infections

People with norovirus illness usually develop symptoms of gastroenteritis within 24 to 48 hours, but symptoms can start as early as 12 hours after exposure. The virus can live on surfaces for long periods of time and survives freezing temperatures. It is highly contagious.

The illness often begins suddenly. Even after having the illness, you can still become reinfected by norovirus. The main symptoms of norovirus illness are diarrhea, vomiting (children usually experience more vomiting than adults), nausea, and stomach cramps.

Other symptoms may include low-grade fever, headache, chills, muscle aches, and fatigue (a general sense of tiredness). Most people feel better within one or two days, with symptoms resolving on their own, and experience no long-term health effects.

As with any illness-causing diarrhea or vomiting, people who are ill should drink plenty of liquids to replace lost body fluids and prevent dehydration. In severe cases, patients may need to be hospitalized and given fluids intravenously.

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Revive Organics Inc. is recalling certain smoothie and oat products from the marketplace because of possible norovirus contamination of the raspberries used in these products.

This recall was triggered by Canadian Food Inspection Agency test results.

The recalled products have been sold nationally in Canada and online.

Recalled products:

BrandProductSizeUPCCodes
Revive SuperfoodsAçaí Twist Smoothie201 g8 54681 00005 32022-10-112022-10-192022-10-202022-11-062022-11-092022-11-12
Revive SuperfoodsBerry Blü Smoothie194 g8 54681 00009 12022-10-132022-10-202022-10-212022-10-272022-11-042022-11-10
Revive SuperfoodsBerry Patch Oats176 g8 54681 00012 12022-10-202022-10-272022-11-03
Revive SuperfoodsCoconut Cream Smoothie190 g8 54681 00016 92022-10-132022-10-192022-10-272022-11-052022-11-12
Revive SuperfoodsHeart Beet Smoothie207 g8 53267 00112 52022-10-072022-10-132022-10-202022-11-03
Revive SuperfoodsRaspberry & Mango Smoothie188 g8 54681 00026 82022-10-132022-10-202022-10-272022-11-022022-11-032022-11-10
Revive SuperfoodsStrawberry ZenSmoothie222 g8 54681 00003 92022-10-122022-10-202022-10-212022-10-222022-11-032022-11-12

As of the posting of this recall, there have been no reported illnesses associated with the consumption of these products.

Recalled products should be thrown out or returned to the location where they were purchased.

About norovirus infections

People with norovirus illness usually develop symptoms of gastroenteritis within 24 to 48 hours, but symptoms can start as early as 12 hours after exposure. The virus can live on surfaces for long periods of time and survives freezing temperatures. It is highly contagious.

The illness often begins suddenly. Even after having the illness, you can still become reinfected by norovirus. The main symptoms of norovirus illness are diarrhea, vomiting (children usually experience more vomiting than adults), nausea, and stomach cramps.

Other symptoms may include low-grade fever, headache, chills, muscle aches, and fatigue (a general sense of tiredness). Most people feel better within one or two days, with symptoms resolving on their own, and experience no long-term health effects.

As with any illness-causing diarrhea or vomiting, people who are ill should drink plenty of liquids to replace lost body fluids and prevent dehydration. In severe cases, patients may need to be hospitalized and given fluids intravenously.

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New Alasko Limited Partnership is recalling Alasko brand IQF Whole Raspberries because of possible norovirus contamination.

This recall comes after a month after a similar recall of Mantab Inc.’s Below Zero brand whole, frozen raspberries because of possible norovirus contamination.

The recalled product has been sold in Canada in Quebec, Ontario and Nova Scotia.

Recalled product:

Brand NameProduct NameSizeCode on ProductUPC
AlaskoIQF Whole Raspberries5 x 1 kg#Lot: SY 21278P.O: 116381-01BB: 2023-OC-04Inner Bag:6 95058 00205 4Outer Carton: 1 069505 800205 16 95058 00205 41 069505 800205 1

Consumers, retailers, and restaurant owners should check to see if they have the recalled products in their homes or establishments. Recalled products should be thrown out or returned to the location where they were purchased.

About norovirus infections

People with norovirus illness usually develop symptoms of gastroenteritis within 24 to 48 hours, but symptoms can start as early as 12 hours after exposure. The virus can live on surfaces for long periods of time and survives freezing temperatures. It is highly contagious.

The illness often begins suddenly. Even after having the illness, you can still become reinfected by norovirus. The main symptoms of norovirus illness are diarrhea, vomiting (children usually experience more vomiting than adults), nausea, and stomach cramps.

Other symptoms may include low-grade fever, headache, chills, muscle aches, and fatigue (a general sense of tiredness). Most people feel better within one or two days, with symptoms resolving on their own, and experience no long-term health effects.

As with any illness-causing diarrhea or vomiting, people who are ill should drink plenty of liquids to replace lost body fluids and prevent dehydration. In severe cases, patients may need to be hospitalized and given fluids intravenously.

(To sign up for a free subscription to Food Safety News, click here.)

Tri-Star Seafood Supply Ltd. is recalling certain Tri-Star Seafood Supply Ltd. brand Live Spot Prawns because of possible norovirus contamination.

This recall was triggered by findings by the Canadian Food Inspection Agency during its investigation into a foodborne illness outbreak.

The recalled product has been sold in British Columbia, Alberta, Manitoba, and Ontario, and may have been distributed in other provinces and territories.

Recalled products:

Brand Product Size UPC Codes
Tri-Star Seafood Supply Ltd. Live Spot Prawn Variable None
  • AJ200-021
  • CA001-1532
  • CA001-1540

Consumers should not consume recalled products. Recalled products should be thrown out or returned to the location where they were purchased.

About norovirus infections
People with norovirus illness usually develop symptoms of gastroenteritis within 24 to 48 hours, but symptoms can start as early as 12 hours after exposure. The virus can live on surfaces for long periods of time and survives freezing temperatures. It is highly contagious.

The illness often begins suddenly. Even after having the illness, you can still become reinfected by norovirus. The main symptoms of norovirus illness are diarrhea, vomiting (children usually experience more vomiting than adults), nausea, and stomach cramps.

Other symptoms may include low-grade fever, headache, chills, muscle aches, and fatigue (a general sense of tiredness). Most people feel better within one or two days, with symptoms resolving on their own, and experience no long-term health effects.

As with any illness-causing diarrhea or vomiting, people who are ill should drink plenty of liquids to replace lost body fluids and prevent dehydration. In severe cases, patients may need to be hospitalized and given fluids intravenously.

(To sign up for a free subscription to Food Safety News, click here.)