Leading lights of Britain’s food safety junta have issued a call for research into norovirus, specifically how the virus continues to survive when it comes into contact with the surfaces that food is prepared upon or with food itself.

They should have just given the money to LeeAnn.

As in LeeAnn Jaykus of North Carolina State University, who was one of the authors of a paper in this month’s issue of my favorite bath time reading, Journal of Food Protection. The authors write:

“Foods become contaminated with HuNoV by direct contact with fecal matter on the hands of food workers who have not practiced adequate personal hygiene and by transfer of virus via contact with contaminated surfaces. Intuitively, this makes sense, as HuNoV are shed in high numbers in the feces and vomitus of infected individuals, and shedding can precede illness, occur in asymptomatic individuals, and/or be prolonged for days to weeks after symptom resolution.

Our results confirm that HuNoV can persist on commonly used food contact surfaces and on a model food for long periods, as evaluated by the only reliable method to detect these viruses, RT-qPCR. This our work confirms that moisture, pressure, and recipient surface were key factors influencing transferability (reviewed in (24) ). For example, transfer of HuNoV and MNV-1 from stainless steel surfaces to lettuce was more efficient when the virus inoculum was still wet (time 0), an observation consistent with previous studies using FCV (8) and rotavirus.

Persistence and transferability of Noroviruses on and between common surfaces and foods
02.may.12
Journal of Food Protection®, Volume 75, Number 5, May 2012 , pp. 927-935(9)
Escudero, B.I.; Rawsthorne, H.; Gensel, C.; Jaykus, L.A.
http://www.ingentaconnect.com/content/iafp/jfp/2012/00000075/00000005/art00016
Abstract:
Human noroviruses (HuNoV) are the leading cause of foodborne disease, and poor personal hygiene practices of infected workers are the most common mode of contamination. The purpose of this study was to characterize the persistence and transferability of representative noroviruses Norwalk virus (NV), Snow Mountain virus (SMV), and murine norovirus 1 (MNV-1) on and between solid surfaces and foods. Changes in virus concentration on artificially inoculated solid surfaces (stainless steel, ceramic, and Formica) or lettuce were monitored over a period of 14 to 42 days. Virus transfer was evaluated from donor (solid surface) to recipient (food, e.g., lettuce and sliced turkey deli meat) for up to 2 h postinoculation. Viruses were recovered by elution and titered with reverse transcription quantitative PCR (RT-qPCR) and/or infectivity assay, as appropriate. Based on RTqPCR, the concentration of NV and SMV on surfaces dropped gradually over time, with an average reduction of 1.5 to 2.0 and 1.8 to 2.3 log, respectively, after 42 days, with no statistically significant differences by surface. When inoculated onto lettuce stored for 2 weeks at 4°C and room temperature, the titers of NV and SMV dropped by approximately 1.0 and 1.2 to 1.8 log, respectively. Comparatively, the RT-qPCR signal associated with purified HuNoV RNA placed on the same surfaces was more rapidly lost to degradation. Transfer efficiency ranged from 0 to 26 % for lettuce and from 55 to 95 % for sliced turkey deli meat, with statistically significant differences (P ≤ 0.05) in transferability as a function of contact pressure (100 and 1,000 g/9 cm2) and inoculum drying time. When similar experiments were done with MNV-1, infectious virus failed to be detected on solid surfaces after storage day 21, although the virus did persist on lettuce. This study provides much needed quantitative data for use in risk assessment efforts intended to characterize the transmission of HuNoV during food preparation and handling.

Health officials are investigating the cause of what sickened 27 people following a luncheon this week for the Pueblo Community Health Center.

"It's too early to implicate the caterer. We're only a day into it and we have 27 people sick out of 80," Dr. Chris Nevin-Woods said Thursday.

"The symptoms are fitting of a number of possibilities, but it could be something other than food," Nevin-Woods said. One possibility could be norovirus.

Janet Fieldman, the health center's chief foundation officer, sent an email Thursday to those who attended the dinner, alerting them to the outbreak and telling them they would be contacted by health officials.

The email was sent to several elected officials at the city and county levels, college leaders, doctors and members of the medical community.

Norovirus was the cause of some cases of nausea, diarrhea and chills that afflicted players and staff at the BNP Paribas Open tennis tournament in March.

The Riverside County Department of Disease said Monday the illness knocked several top players out of the world-class BNP event at the Indian Wells Tennis Garden.

“Some individuals were tested and we did have some positive results for norovirus,” said Barbara Cole, director of disease control for the Riverside County Department of Health.

“We did have some people that were linked to the tournament, but we can't say definitively that everyone who was ill had norovirus.”

Among the players who withdrew from the event were Nikolay Davydenko, Vani King, Gaels Monfils, Francesa Schiovone and doubles specialist Mike Bryan. Both women's No. 1 seed Victoria Azarenka and men's champion Roger Federer complained about symptoms during the two-week event, though Federer insisted he had the illness before arriving in Indian Wells.

Oysters from Australian waters are a delight on the grill, although I’ve graduated to scallops on the half-shell, also grilled.

But whenever I go see Paul the fish monger, he’s offering me a sample of his wares – raw – and I politely decline.

Or, as Dr. Ken Buckle, professor emeritus at the University of New South Wales commented when our hosts took us to a seafood buffet in Abu Dhabi, I spent too much time researching pathogens in raw fish.

He chose the cooked kind.

The U.S. Centers for Disease Control recently described a norovirus outbreak in frozen raw oysters in Seattle imported from South Korea.

On October 19, 2011, Public Health – Seattle & King County was contacted regarding a woman who had experienced acute gastroenteritis after dining at a local restaurant with friends. Staff members interviewed the diners and confirmed that three of the seven in the party had consumed a raw oyster dish.

Within 18–36 hours after consumption, the three had onsets of aches, nausea, and nonbloody diarrhea lasting 24–48 hours. One ill diner also reported vomiting. The four diners who had not eaten the raw oysters did not become ill.

An inspection of a walk-in freezer at the restaurant revealed eight 3-pound bags of frozen raw oysters, which the restaurant indicated had been an ingredient of the dish consumed by the ill diners. The oysters had been imported from South Korea by company A and shipped to a local vendor, which sold them to the restaurant. All eight bags were sent to the Food and Drug Administration's Gulf Coast Seafood Laboratory for norovirus testing and characterization by real-time reverse transcription–polymerase chain reaction (rRT-PCR).

A stool specimen from one of two ill diners collected 17 days after symptom onset tested positive for norovirus; sequence analysis identified GI.1 and GII.17 strains. Sequence analysis of the oysters identified a GII.3 strain. Because oysters can harbor multiple norovirus strains that are unequally amplified by rRT-PCR, discordance between stool specimens and food samples in shellfish-associated norovirus outbreaks is common and does not rule out an association. On November 4, 2011, company A recalled its frozen raw oysters.

The frozen oysters implicated in this outbreak were distributed internationally and had a 2-year shelf-life. Contamination of similar products has been implicated previously in international norovirus transmissions. Such contamination has potential for exposing persons widely dispersed in space and time, making cases difficult to identify or link through traditional complaint-based surveillance.