Human norovirus (HuNoV) is a foremost cause of domestically acquired foodborne acute gastroenteritis and outbreaks. Despite industrial efforts to control HuNoV contamination of foods, its prevalence in foodstuffs at retail is significant. HuNoV infections are often associated with the consumption of contaminated produce, including ready-to-eat (RTE) salads.
Decontamination of produce by washing with disinfectants is a consumer habit which could significantly contribute to mitigate the risk of infection. The aim of our study was to measure the effectiveness of chemical sanitizers in inactivating genogroup I and II HuNoV strains on mixed salads using a propidium monoazide (PMAxx)-viability RTqPCR assay. Addition of sodium hypochlorite, peracetic acid, or chlorine dioxide significantly enhanced viral removal as compared with water alone. Peracetic acid provided the highest effectiveness, with log10 reductions on virus levels of 3.66 ± 0.40 and 3.33 ± 0.19 for genogroup I and II, respectively. Chlorine dioxide showed lower disinfection efficiency.
Our results provide information useful to the food industry and final consumers for improving the microbiological safety of fresh products in relation to foodborne viruses.
Effectiveness of consumers washing with sanitizers to reduce human norovirus on mixed salad
Eduard Anfruns-Estrada, Marilisa Bottaro, Rosa Pinto, Susana Guix, Albert Bosch
The case study is part of a wider project done by ECDC within the context of EU Decision 1082/2013/EU on serious cross-border threats to health. It is part of a multi-country case study project that investigates the synergies between communities affected by serious public health threats and the institutions (both health- and non-health-related) mandated to prepare for and respond to them.
The premise for the project is that affected communities are increasingly recognised as key resources in public health emergencies, and that the concerns and experiences of ordinary people should be harnessed as an important part of the response.
Community engagement and institutional collaboration in Iceland during a norovirus outbreak at an outdoor/scout centre (10-15 August 2017)
CBS News reports the rapid spread of a stomach virus through the Greater Albany School District has forced the closure of all schools in the district for the rest of the week. The closure comes days after a Colorado school district of about 22,000 students was forced to close after a similar viral outbreak tore through its 46 schools.
CBS Portland affiliate KOIN-TV reported the school district in Linn County, Oregon, was trying to contain the spread of the virus, which causes vomiting and diarrhea.
The district disinfected buildings over the weekend, but kept Periwinkle Elementary School closed Monday after consulting with the Linn County Health Department. On Monday evening, the Greater Albany district said on Facebook that after consulting with state and county health officials — and noting a jump in absences in their other schools — that all schools would close and reopen December 2.
Officials said cleaning teams will continue to disinfect and sanitize throughout the closure.
In Colorado, hundreds of students were sickened by symptoms similar to those of norovirus, a highly-contagious virus that causes vomiting and diarrhea. After the illness jumped quickly from school to school, officials were forced to take the unusual step of closing all 46.
“When we have 20 kids actively vomiting in a school that already has 17% gone we know that we’ve got a problem. We have to stop the exposure,” said Tanya Marvin, the head of nursing for the school district.
Sydney woman Lesley Thompson was enthusiastic about her journey across the heart of Australia when she stepped onto the Indian Pacific train with her sister Pam last month.
But in less than 24 hours the elderly woman was being rushed to hospital in an ambulance, struck down with a “vile” case of gastro that began to cause trouble with her heart.
Carrie Fellner of the Sydney Morning Herald reports Ms Thompson is one of at least 100 passengers to have fallen ill in a mass outbreak of norovirus, a form of gastroenteritis, on the Indian Pacific train in recent weeks.
The 80-year-old, from Greenwich on Sydney’s north shore, was relieved she was in good health with no pre-existing heart problems, and has been able to recover from her ordeal.
The Indian Pacific train travels from Sydney to Perth via Adelaide, crossing the Nullarbor Plain on its 4352-kilometre journey.
More than 100 people have become ill with gastro after travelling on the Indian Pacific train.
The first case linked to the train was recorded on September 8 and the latest case was identified on Monday September 30.
Ms Thompson has been unable to get through to health authorities and does not know if they have counted her among the two passengers reported as requiring hospitalisation.
She boarded the train on September 11 in Sydney and fell ill during a stopover in the South Australian town of Hahndorf the following day.
“I was throwing up everywhere,” she said. “It was vile.”
Ms Thompson is yet to receive a refund on the ticket cost of nearly $10,000, and was initially told she had to pay a “curtailment fee” for abandoning the train during the stopover.
A spokesperson for Great Southern Rail, which operates the service, said it was still working through compensation options for affected guests on a case-by-case basis.
The Indian Pacific remains in operation but SA Health said it had the power to take the train off the tracks if the situation escalates.
“The health and wellbeing of guests is paramount and we have acted quickly to respond to this situation,” a spokesperson said.
This is the CIDRAP summary of the latest CDC number crunching on microorganisms that lead to barfing.
The Centers for Disease Control and Prevention (CDC) late last week released a summary of foodborne illnesses in 2017 based on an annual analysis of data from the Foodborne Disease Outbreak Surveillance System, and norovirus was the most common pathogen reported, responsible for 46% of illnesses. Salmonella and Shiga toxin–producing Escherichia coli were also linked to a substantial number of outbreaks.
In 2017, the CDC tracked 841 foodborne outbreaks, which included 14,481 illnesses, 827 hospitalizations, 20 deaths, and 14 food product recalls. A single etiologic agent was confirmed in 395 outbreaks (47%), which are defined as two or more related cases.
Tainted seafood and poultry were tied with causing the most outbreaks, with mollusks (41 outbreaks), fish (37), and chicken (23) the specific food items most often implicated. The most outbreak-associated illnesses were from turkey (609 illnesses), fruits (521), and chicken (487), the CDC said.
California had the most outbreaks (107), followed by Ohio (69), and Washington state (67).
As in past years, restaurants with sit-down dining were the most commonly reported locations for food preparation associated with outbreaks (366).
Parents at Norwich Primary Academy say an outbreak of the vomiting bug at the end of last week caused dozens of children to fall ill.
One parent claimed almost a quarter of the school’s 350 pupils were absent at the end of last week and questioned why the school had not been closed.
Norwich Primary Academy did not confirm or deny whether any cases of norovirus has been reported, saying it could not comment on individual cases, but added that it took pupil health seriously and followed all relevant health protection guidelines.
One parent, whose children are in year one and year three at Norwich Primary Academy, said a group social media chat for parents at the school has reportedly been awash with talk of children and other family members falling victim to sickness and diarrhea.
“It is speculation from the teachers at the moment,” she said.
“There were 18 children in a year one class out of 30 on Friday morning and 10 on Friday afternoon. The children are dropping like flies.”
Rebecca Trager of Chemistry World reports U.S. researchers have created a handheld detection system that is sensitive enough to catch just a few particles of norovirus.
University of Arizona biomedical engineer Jeong-Yeol Yoon and his team have created a highly sensitive portable detection system capable of spotting norovirus at levels that can make people sick. The work was presented the American Chemical Society’s national meeting in San Diego, California on 27 August.
As few as 10 norovirus particles can cause vomiting and diarrhoea in humans and the virus is extremely contagious so early detection is vital to prevent outbreaks. However, the virus does not grow in laboratory cultures and current detection methods rely on specialised and time-consuming PCR (polymerase chain reaction) techniques.
Yoon’s research team previously developed a smartphone-based device that measured light-scattering from norovirus-bound polystyrene beads in a paper microfluidic chip. It has now improved the device’s detection limit by changing to a fluorescence-based method.
‘I looked at Amazon.com and saw that they sell a lot of these smartphone attachments – smartphone microscope attachments – that turn your phone turns into a microscope, and by adding a couple of other components, I could convert the smartphone-based microscope into a fluorescence microscope,’ Yoon explains.
The setup uses a microscope accessory with a separate light source and two optical filters. He and colleagues also designed a 3D printed case to house the components.
To test a sample, it is first added to the paper microfluidic chip, followed by a suspension of fluorescent beads labelled with norovirus antibodies. After three to five minutes, the antibodies bind to any norovirus particles in the sample, creating aggregates of the fluorescent beads that spread out along the channels of the chip. The resulting increase in fluorescence intensity around each norovirus particle can be detected by taking a picture of the chip with the smartphone’s camera.
An app that the team has also developed then analyses the picture to calculate the sample’s norovirus concentration from the pixel count in the image. So far, the lowest detection limit corresponded to about 5 or 6 norovirus particles per sample, Yoon says. He estimates that the material costs of this system, aside from the cell phone and app development costs, are about $200.
The apparent international rise in foodborne virus outbreaks attributed to fresh produce and the increasing importance of fresh produce in the Australian diet has led to the requirement to gather information to inform the development of risk management strategies.
A prevalence survey for norovirus (NoV) and hepatitis A virus (HAV) in fresh Australian produce (leafy greens, strawberries and blueberries) at retail was undertaken during 2013–2014 and data used to develop a risk profile. The prevalence of HAV in berries and leafy greens was estimated to be <2%, with no virus detected in produce during the yearlong survey. The prevalence of NoV in fresh strawberries and blueberries was also estimated to be <2% with no virus detected in berries, whilst for leafy greens the NoV prevalence was 2.2%.
Prevalence of a bacterial hygiene indicator, Escherichia coli, was also investigated and found to range from <1% in berries to 10.7% in leafy greens. None of the NoV positive leafy green samples tested positive for E. coli, indicating it is a poor indicator for viral risk.
The risk was evaluated using standard codex procedures and the Risk Ranger tool. Taking all data into account, including the hazard dose and severity, probability of exposure, probability of infective dose and available epidemiological data, the risk of HAV and NoV foodborne illness associated with fresh Australian berries (strawberries and blueberries) sold as packaged product was deemed to be low. The risk of foodborne illness from HAV associated with leafy greens was also deemed to be low, but higher than that for fresh berries, due mainly to the potential for recontamination post-processing if sold loose. The risk of foodborne illness from NoV associated with leafy greens was deemed to be low/moderate. Despite the prevalence of NoV in leafy greens being low and the inability to discriminate between infective and non-infective virus using PCR based methodologies, the fact that NoV was detected resulted in a higher risk associated with this pathogen-product pairing; compounded by the higher prevalence of NoV within the community compared to HAV, and the potential for leafy greens to become contaminated following processing if sold loose.
Estimating risk associated with human norovirus and hepatitis A virus in fresh Australian leafy greens and berries at retail 26 August 2019