Norovirus Link Closed Louisiana Oyster Beds

The Advocate reported today, “oyster bed closures “safety net.”

The closure of some oyster harvesting grounds in southwest Louisiana this week highlights how pollution can impact the state’s fishing industry. The state Department of Health and Hospitals halted oyster harvesting in lower Calcasieu Lake on Thursday on the suspicion that oysters from the area might have been linked to a norovirus outbreak in North Carolina.

Public health officials in Raleigh, N.C., reported that about 280 people became sick last month after dining at an oyster bar that served oysters from the area in question.

Norovirus is a name applied to a group of highly contagious and fairly common illnesses that cause flu-like symptoms for one to two days.

It can find its way into oysters by way of sewage run-off.

Norovirus and other food-borne illnesses linked to run-off are such a concern that Louisiana has a system in place that calls for the precautionary closure of oyster harvesting in certain areas based on the conditions and times of year that can be problematic.

FDA - Texas Oysters have Norovirus - Illnesses Linked in North and South Carolina

The U.S. government warned consumers Sunday to avoid oysters from San Antonio Bay in Texas after investigators found the oysters caused a highly contagious virus.

Consumers who bought San Antonio Bay-harvested oysters on or after November 16 should throw them away, the Food and Drug Administration announced. The agency also advised restaurant managers and grocers not to serve or sell the Texas oysters.

About a dozen cases of norovirus-related illnesses in North Carolina and South Carolina were "definitely linked" to oysters recently harvested from the San Antonio Bay, FDA spokeswoman Rita Chappelle told CNN.

Texas' health department has already recalled all oysters harvested from the bay between November 16 and November 25, the health department said in a statement on its Web site. San Antonio Bay has also been closed to commercial oyster harvesting, the statement said.

Texas authorities are still investigating how the oysters were contaminated and where they were distributed, Chappelle said.

Noroviruses cause gastroenteritis, also known as the stomach flu. They are highly contagious, according to the Centers for Disease Control and Prevention. Aside from contracting the virus from food or drink, one can become ill by touching contaminated surfaces and then their mouth, or by coming into direct contact with an infected individual.

Symptoms associated with the virus include nausea, vomiting, diarrhea and stomach cramping. Affected individuals often experience low-grade fever, chills, headache, muscle aches and fatigue. The illness typically lasts one to two days according to the CDC.

Anyone who ate the now-recalled oysters and who are now showing symptoms of norovirus should see a doctor and contact the local health department.

Effects of technological processes on the tenacity and inactivation of norovirus GGII in experimentally contaminated foods

American Society for Microbiology
Sascha Mormann, Mareike Dabisch, and Barbara Becker

Abstract

Contaminated food is a significant vehicle of human norovirus transmission. The present study determined the effect of physicochemical treatments on the tenacity of infective human norovirus genogroup II in selected foods. Artificially contaminated produce was subjected to a selection of processes used by the food industry for preservation and by the consumer for storage and preparation. Virus recovery was carried out by ultrafiltration and monitored with bacteriophage MS2 as an internal process control. Norovirus was quantified with monoplex one-step TaqMan real-time RT-PCR and an external standard curve based on recombinant RNA standards. A RNase pretreatment step was introduced to avoid false-positive PCR results caused by accessible RNA allowing the detection of intact virus particles. Significant titer reductions were obtained with heat treatments usually applied by the consumer for food preparation (baking, cooking, roasting). Generally, processes for preservation and storage, such as cooling, freezing, acidification ( pH 4.5) and moderate heat treatments (pasteurization) appear to be insufficient to inactivate norovirus within a food matrix or on the surface. Beside the persistence in processed food, this study provides comparable data about individual matrix-specific protective effects, recovery rates and inhibitory influences on the PCR reactions. The established workflow might be applied to other non-cultivable enteric RNA viruses which are connected to foodborne diseases. The obtained data of this project may also benefit the process optimization for norovirus inactivation in food by adjusting food processing technologies and promote the development of risk assessment systems in order to improve the consumer protection.

Norovirus Outbreaks Linked to Cruise Ship Bathrooms

A study suggests one possible culprit: dirty restrooms.  Most restrooms on these ships are not being properly cleaned, the authors say, and a sanitation program run by the Centers for Disease Control and Prevention does not detect the dirty ones.

According to researchers writing in the Nov. 1 issue of Clinical Infectious Diseases, the C.D.C. identified contamination with norovirus as the problem in almost all of these infections. But the ships generally had high passing scores on the inspection closest to their outbreaks. In fact, their scores were on average higher than those of ships with passengers who had no episodes of diarrheal disease.

Norovirus can survive for weeks on surfaces at room temperature, and it is difficult to kill. “It’s a tough virus,” said the lead author of the study, Dr. Philip C. Carling. “It isn’t killed by alcohol hand rubs. Chlorine bleach is the only thing that works.”

There were 19 outbreaks of intestinal illness during the 3-year study period. Although the survey was not designed to detect norovirus or establish the cause of any illness, the restroom cleanliness scores were slightly lower on ships that had outbreaks than on those that had none.

The difference was not statistically significant, but the authors said the findings were consistent with the possibility that restroom contamination contributed to norovirus epidemics.

“We’re not saying that poor cleaning causes norovirus outbreaks,” Dr. Carling said, adding, “I believe that one or more people with norovirus who handle food, or possibly a passenger, comes down with norovirus, and substandard hygiene serves as a facilitator of the spread in a closed population.”

Norovirus Death of Dr. Edward Nacht Linked to Weston Hills Country Club

A norovirus, which can be passed by food, likely was what killed a Weston, FL dentist who was one of four friends to get sick shortly after eating lunch at Weston Hills Country Club in June, a new Broward County Health Department report says.

But the report this week stopped short of naming the club as the source of the virus, and state regulators have taken no disciplinary action. Dr. Edward Nacht could have caught norovirus from his chicken quesadilla lunch, because at least one food-service worker at the club had it, but lab tests did not prove it, the report says.

"This report is not showing any punitive actions," said department spokeswoman Candy Sims, who declined to elaborate.

The club has denied wrongdoing or that Nacht died from his lunch. A spokeswoman could not be contacted for comment despite calls to her office and mobile phone.

But Nacht's family said the test results show what happened.

"If Dr. Nacht hadn't eaten there, he would still be alive today," Dr. Jason Hirsh, Nacht's son-in-law and dental partner, said Friday."Norovirus was the cause of the outbreak and there was norovirus in the employees."

Norovirus, a common cause of disease known for outbreaks on cruise ships, spreads most often from fecal material on unwashed hands.

Nacht and three friends ate lunch at the club after playing golf, and all got sick within a day. Nacht never recovered, and died days later in a hospital. A state inspection found food safety violations, including improperly warm coolers and raw foods touching each other. Health officials found 21 others who got sick after eating at the club in that time frame, but did not link them to Nacht.

Polish Raspberries cause Norovirus Outbreak in Finland

Noroviruses are part of a group of viruses understood to be the most common cause of stomach upset. They cause nausea, vomiting and diarrhea, and people may also have a fever and head and muscle pains. Although an individual’s symptoms may pass in one or two days, the disease is highly contagious and remains in the faeces for several weeks afterwards.

Finland was hit by outbreaks of the bug in May and June, and analysis confirmed that Polish raspberries were the cause. The fruits are now suspected as having caused the new cases have been reported in the south since the beginning of this month. Evira has not said now many people are currently known to have become sick, but they are thought to have been infected after eating desserts and cakes made with frozen raspberries that have not been heated before use. The virus can enter the fruit through contaminated irrigation water, and it stays alive and contagious during freezing. In order to safeguard against infection, users of foreign frozen raspberries should heat the fruit to 90 ºC for at least two minutes, says Evira. Slight heating after defrosting is not enough to ensure the raspberries are safe.

Free Meals at The Fat Duck - You need Norovirus First

When I was in England in May I tried to get reservations at Heston Blumenthal's Fat Duck.  Whether is was my profession or that it was actually busy, I do not know.  However, now more than 500 diners who suffered food poisoning after eating at the Fat Duck restaurant have been offered a free meal.

A norovirus outbreak hit the Michelin-starred establishment in Berkshire for six weeks in January and February.  Although the restaurant denied lapses in its food preparation, health investigators criticised its response in a recent report.  During the norovirus outbreak, diners reported bouts of vomiting and diarrhoea.

In its report released earlier this month, the Health Protection Agency said the norovirus was probably introduced via shellfish. But it said the outbreak of food poisoning was worsened by the Bray restaurant's "delayed response". Investigators noted several weaknesses in the restaurant's procedures at the establishment in Bray which may have lead to the spread of the virus. These included a delayed response to the illness, staff working when they should have been off sick and the use of the wrong environmental cleaning products.

Perhaps next time - NOT.

Norovirus Experts Gather In London on Nov. 25h

An international conference for sharing experiences and updates on current knowledge of the Norovirus and managing outbreaks in both clinical and community settings is set for Wednesday, Nov. 25, 2009 in London.

Sponsor of the one day event is the Royal Society for Public Health.

"Norovirus used to be known as the 'winter vomiting virus,' but now could claim the title of the 'cruise ship bug,' given it's prolificacy in that environment," the sponsors write, "Norvirus is known for its dominance of the gastrointestinal infection statistics and its ability to close down hospital wards or hotels when it strikes."

Speakers will include Norovirus experts from the United States, England, and Ireland.  It will include focuses on managing outbreaks in large hotels and holiday camps, and cruise ships in addition to cleaning the environment and control the spread of the virus across borders.

Norovirus accounts for 50 percent of worldwide foodborne gastroenteritis (diarrhea and vomitting) outbreaks.  It accounts for an estimated 23 million illnesses annually in the U.S.

For more information and registration go to the Booking Form for: Norovirus: An On going Challenge. 

Norovirus: An Ongoing Challenge

25 November 2009

28 Portland Place, London, W1B 1DE

Tab 1: Conference overview

Norovirus outbreaks remain a major public health concern and the subject of much media attention.

It is estimated that Norovirus accounts for 50% of worldwide food borne gastroenteritis (diarrhoea and vomiting) outbreaks and causes more than 23 million cases of acute gastroenteritis a year in the USA alone. It is also the most prevalent cause of infectious gastroenteritis in England and Wales – and is now recognised to occur throughout the year and affect individuals of any age.

Norovirus used to be known as the ‘winter vomiting virus’, but now could claim the title of the ‘cruise ship bug’, given it’s prolificacy in that environment. Norovirus is also known for its dominance of the gastrointestinal infection statistics and its ability to close down hospital wards or hotels when it strikes.

With the continuing difficulties involved in controlling outbreaks of Norovirus, this conference will share experiences and update delegates on current knowledge of the virus and managing outbreaks, both in clinical and community settings.

The conference will be chaired by Professor Rodney Cartwright, Medical Microbiologist and RSPH advisor.

Who should attend?

This meeting will provide an excellent opportunity to update on the issues surrounding Norovirus infection and outbreak. It is essential learning for those working in the health sector, environmental health, the cleaning products industry, the cruise ship industry and anyone working in infection control.

For more information, please contact Jennifer Tatman, Conference and Event Officer on 020 3177 1614 or jtatman@rsph.org.uk.

Shellfish Blamed For Norovirus Outbreak At Fat Duck

 The New York Times says the Fat Duck restaurant is one of the world's best, so it must be true.  We thought it might be interesting to read the British Health Protection Agency's report on last winter's Norovirus outbreak that made 529 duck diners sick.  In part it says:

The investigation was conducted by the HPA and Environmental Health Officers from the Royal Borough of Windsor and Maidenhead. Berkshire East Primary Care Trust was also involved. The final report has been delayed due to the swine flu pandemic which required priority response from the Health Protection Agency.

Investigations focused on laboratory testing of diners with symptoms of diarrhoea and vomiting (where possible); analysis of detailed questionnaires sent to others who reported similar illness; investigation of illness among staff; examination of the restaurant environment and food processing, handling and supply; laboratory testing of food samples.

Putting together findings from all these parts of the investigation, the main conclusions were that:

  • There was a large outbreak of food poisoning among diners at the Fat Duck Restaurant in January and February 2009, with more than 500 reporting illness - over 15 percent of those dining there during this period
  • The organism responsible was norovirus which was probably introduced via shellfish (more diners who ate shellfish dishes reported illness). Oysters were served raw; razor clams may not have been appropriately handled or cooked; tracing of shellfish to source showed evidence of contamination and there have been reports of illness in other establishments associated with oysters from the same source
  • The outbreak continued for at least six weeks (between January 6 and February 22) because of ongoing transmission at the restaurant - which may have occurred through continuous contamination of foods prepared in the restaurant or by person-to-person spread between staff and diners or a mixture of both
  • Several weaknesses in procedures at the restaurant may have contributed to ongoing transmission including: delayed response to the incident; staff working when they should have been off sick and using the wrong environmental cleaning products
  • Delays in notification of illness may have affected the ability of the investigation to identify the exact reason for the norovirus contamination.

The Fat Duck told the New York Times it knew of no employee who worked while sick.