Tag Archives: who

WHO chimes in: Risk of Vibrio

Posted on by
Reply

There has been an increase in reported outbreaks and cases of foodborne disease attributed to pathogenic Vibrio species. As a result, there have been several instances where the presence of pathogenic Vibrio spp. in seafood has led to a disruption in international trade. The number of Vibrio species being recognized as potential human pathogens is increasing. The food safety concerns associated with these microorganisms have led to the need for microbiological risk assessment to support risk management decision making for their control.

V. parahaemolyticus is considered to be part of the autochthonous microflora in the estuarine and coastal environments in tropical to temperate zones. Food safety concerns have been particularly evident with V. parahaemolyticus. There have been a series of pandemic outbreaks of V. parahaemolyticus foodborne illnesses due to the consumption of seafood. In addition, outbreaks of V. parahaemolyticus have occurred in regions of the world where it was previously unreported. The vast majority of strains isolated from patients with clinical illness produce a thermostable direct haemolysin (TDH) encoded by the tdh gene. Clinical strains may also produce a TDH-related haemolysin (TRH) encoded by the trh gene. It has therefore been considered that those strains that possess the tdh and/or trh genes and produce TDH and/or TRH should be considered those most likely to be pathogenic. V. vulnificus can occasionally cause mild gastroenteritis in healthy individuals following consumption of raw bivalve molluscs. It can cause primary septicaemia in individuals with chronic pre-existing conditions, especially liver disease or alcoholism, diabetes, haemochromatosis and HIV/AIDS. This can be a serious, often fatal, disease with one of the highest fatality rates of any known foodborne bacterial pathogen.

The 41st Session of the Codex Committee on Food Hygiene (CCFH) requested FAO/WHO to convene an expert meeting to address a number of issues relating to V. parahaemolyticus and V. vulnificus including:

  • conduct validation of the predictive risk models developed by the United States of America based on FAO/WHO risk assessments, with a view to constructing more applicable models for wider use among member countries, including adjustments for strain virulence variations and ecological factors;
  • review the available information on testing methodology and recommend microbiological methods for Vibrio spp. used to monitor the levels of pathogenic Vibrio spp. in seafood and/or water; and,
  • conduct validation of growth rates and doubling times for V. parahaemolyticus and V. vulnificus in Crassostrea virginica (Eastern or American oyster) using strains isolated from different parts of the world and different bivalve molluscan species.

The requested expert meeting was held on 13-17 September 2010, and this report is the outcome of this meeting. Rather than undertaking a validation exercise, the meeting considered it more appropriate to undertake an evaluation of the existing risk calculators with a view to determining the context to which they are applicable and potential modifications that would need to be made to extend their application beyond that context. A simplified calculator tool could then be developed to answer other specific questions routinely. This would be dependent on the availability of the appropriate data and effort must be directed towards this.

The development of microbiological monitoring methods, particularly molecular methods for V. parahaemolyticus and V. vulnificus is evolving rapidly. This means the identification of any single method for the purposes of monitoring these pathogens is challenging and also of limited value as the method is likely to be surpassed within a few years. Therefore, rather than making any single recommendation, the meeting considered it more appropriate to indicate a few of the monitoring options available while the final decision on the method selected will depend to a great extent on the specific purpose of the monitoring activity, the cost, the speed with which results are required and the technical capacity of the laboratory.

The meeting considered that monitoring seawater for V. parahaemolyticus and V. vulnificus in bivalve growth and harvest areas has limited value in terms of predicting the presence of these pathogens in bivalves. A linear relationship between levels of the vibrios in seawater and bivalves was not found and whatever relationship does exist can vary between region, the Vibrio spp. etc. Also, the levels of Vibrio species of concern in seawater tend to be very low. This presents a further challenge as the method used would need to have an appropriate level of sensitivity for their detection. Nevertheless, this does not preclude the testing of seawater for these vibrios; for example, in certain situations testing can provide an understanding of the aquatic microflora in growing areas. Monitoring of seafood for these pathogenic vibrios was considered the most appropriate way to get insight into the xii levels of the pathogens in these commodities at the time of harvest. Monitoring on an ongoing basis could be expensive, so consideration could be given to undertaking a study over the course of a year and using this as a means to establish a relationship between total and pathogenic V. parahaemolyticus and V. vulnificus in the seafood and abiotic factors such as water temperature and salinity. Once such a relationship is established for the harvest area of interest measuring these abiotic factors may be a more cost-effective way of monitoring. The meeting undertook an evaluation exercise rather than attempting to validate the existing growth models. The experts considered the JEMRA growth model for V. vulnificus and the FDA growth model for V. parahaemolyticus were appropriate for estimating growth in the American oyster (Crassostrea virginica). The JEMRA growth model for V. vulnificus was appropriate for estimating growth in at least one other oyster species, Crassostrea ariakensis. The FDA model for V. parahaemolyticus was also appropriate for estimating growth in at least one other oyster species, Crassostrea gigas, but was not appropriate for predicting growth in the Sydney rock oyster (Saccostrea glomerata). There was some evidence that the V. parahaemolyticus models currently used over predict growth at higher temperatures (e.g. > 25 °C) in live oysters. This phenomenon requires further investigation. Growth model studies were primarily undertaken using natural populations of V. parahaemolyticus as these were considered to be the most representative. Data were limited and inconsistent with respect to the impact of the strain on growth rate although recent studies in live oysters suggest differences exist between populations possessing tdh/trh (pathogenic) versus total or non-pathogenic populations of V. parahaemolyticus. There was no data to evaluate the performance of the growth models in any other oyster species or other filter feeding shellfish or other seafood and as such its use in these products could not be supported. If the models are used there should be a clear understanding of the associated uncertainty. This indicated a data gap which needs to be addressed before the risk assessments could be expanded in a meaningful manner.

Risk assessment tools for vibrio parahaemolyticus and vibrio vulnificus associated with seafood, 2020

World Health Organization

https://apps.who.int/iris/bitstream/handle/10665/330867/9789240000186-eng.pdf?sequence=1&isAllowed=y

What foods are most likely to cause illness by shiga toxin-producing Escherichia coli (STEC) and how best to control secondary infections

Posted on by
Reply

Two abstracts attempt to provide guidance to these important questions to reduce the toll of STEC.

FAO and WHO conclude shiga toxin-producing Escherichia coli (STEC) infections are a substantial public health issue worldwide, causing more than 1 million illnesses, 128 deaths and nearly 13 000 Disability-Adjusted Life Years (DALYs) annually.

To appropriately target interventions to prevent STEC infections transmitted through food, it is important to determine the specific types of foods leading to these illnesses.

An analysis of data from STEC foodborne outbreak investigations reported globally, and a systematic review and meta-analysis of case-control studies of sporadic STEC infections published for all dates and locations, were conducted. A total of 957 STEC outbreaks from 27 different countries were included in the analysis.

Overall, outbreak data identified that 16% (95% UI, 2-17%) of outbreaks were attributed to beef, 15% (95% UI, 2-15%) to produce (fruits and vegetables) and 6% (95% UI, 1-6%) to dairy products. The food sources involved in 57% of all outbreaks could not be identified. The attribution proportions were calculated by WHO region and the attribution of specific food commodities varied between geographic regions.

In the European and American sub-regions of the WHO, the primary sources of outbreaks were beef and produce (fruits and vegetables). In contrast, produce (fruits and vegetables) and dairy were identified as the primary sources of STEC outbreaks in the WHO Western Pacific sub-region.

The systematic search of the literature identified useable data from 21 publications of case-control studies of sporadic STEC infections. The results of the meta-analysis identified, overall, beef and meat-unspecified as significant risk factors for STEC infection. Geographic region contributed to significant sources of heterogeneity. Generally, empirical data were particularly sparse for certain regions.

Care must be taken in extrapolating data from these regions to other regions for which there are no data. Nevertheless, results from both approaches are complementary, and support the conclusion of beef products being an important source of STEC infections. Prioritizing interventions for control on beef supply chains may provide the largest return on investment when implementing strategies for STEC control.

Second up, in 2016, we reviewed preventive control measures for secondary transmission of Shiga-toxin producing Escherichia coli (STEC) in humans in European Union (EU)/European Free Trade Association (EEA) countries to inform the revision of the respective Norwegian guidelines which at that time did not accommodate for the varying pathogenic potential of STEC.

We interviewed public health experts from EU/EEA institutes, using a semi-structured questionnaire. We revised the Norwegian guidelines using a risk-based approach informed by the new scientific evidence on risk factors for HUS and the survey results.

All 13 (42%) participating countries tested STEC for Shiga toxin (stx) 1, stx2 and eae (encoding intimin). Five countries differentiated their control measures based on clinical and/or microbiological case characteristics, but only Denmark based their measures on routinely conducted stx subtyping. In all countries, but Norway, clearance was obtained with ⩽3 negative STEC specimens. After this review, Norway revised the STEC guidelines and recommended only follow-up of cases infected with high-virulent STEC (determined by microbiological and clinical information); clearance is obtained with three negative specimens.

Implementation of the revised Norwegian guidelines will lead to a decrease of STEC cases needing follow-up and clearance, and will reduce the burden of unnecessary public health measures and the socioeconomic impact on cases. This review of guidelines could assist other countries in adapting their STEC control measures.

Mapping of control measures to prevent secondary transmission of STEC infections in Europe during 2016 and revision of the national guidelines in Norway

Cambridge University Press vol. 147

  1. Veneti(a1)(a2), H. Lange (a1), L. Brandal (a1), K. Danis (a2) (a3) and L. Vold 

DOI: https://doi.org/10.1017/S0950268819001614
https://www.cambridge.org/core/journals/epidemiology-and-infection/article/mapping-of-control-measures-to-prevent-secondary-transmission-of-stec-infections-in-europe-during-2016-and-revision-of-the-national-guidelines-in-norway/1990D2338B220F80F0E683DF6F622A40

Raw is risky: At least 40 sick linked to 2 Canadian oyster farms

Posted on by
Reply

Two B.C. Vancouver Island oyster farms have been closed following an outbreak of norovirus associated with eating the raw shellfish.

The B.C. Centre for Disease Control says about 40 cases of acute gastrointestinal illness have been connected to the consumption of raw oysters since March. Testing has confirmed some of the cases were norovirus.

Federal officials with Fisheries and Oceans Canada (DFO) confirmed the affected farms are located on the east coast of Vancouver Island at Deep Bay and Denman Island.

While the two farms are no longer harvesting oysters for consumption, no recall of oysters has been issued by the Canadian Food Inspection Agency.

While the precise sources of contamination have not been identified, human sewage in the marine environment is currently believed to be the most plausible cause of shellfish contamination, according to BCCDC epidemiologist Marsha Taylor.

In late 2016 and early 2017, more than 400 norovirus cases associated with raw or undercooked B.C. oysters led to the closure of 13 farms.

The outbreak was declared over in April 2017. Human sewage was also suspected as the cause.

In order to kill norovirus and other pathogens, the BCCDC recommends consumers cook oysters thoroughly, to an internal temperature of 90 C for 90 seconds. Consumption of raw oysters is not encouraged.

Use a tip sensitive thermometer and stick it in.

And stop eating raw: It’s just a put on.

(The video is from The Who’s farewell concert in Toronto in 1982, which I watched in my girlfriend’s residence in 1982 at uni, but they’re still around to make a buck, just like food hacks. At least Towsend had tales to tell)

Food safety is every day (and every meal)

Posted on by
Reply

The world does not need a food safety day.

It needs day-in-day-out commitment.

The United Nations‘ General Assembly will discuss in Sept. whether to establish a World Food Safety Day.

The U.N.’s Food and Agriculture Organization has already adopted a draft resolution that puts the wheels in motion for this international day. The resolution has been forwarded to the secretary-general of the United Nations so that it can be added to the organization’s September agenda. If the resolution passes through the General Assembly, World Food Safety Day would be set for June 7 of each year, the F.A.O. says.

World Food Safety Day would “raise awareness of the global threat posed by foodborne diseases and reinforce the need for governments, the food industry, and individuals to do more to make food safe and prevent these diseases,” said Ren Wang, director of F.A.O.’s Department of Agriculture and Consumer Protection.

The draft resolution clearly states that “there is no food security without food safety, and that in a world where the food supply chain has become global, any food safety incident has global negative effects on public health, trade, and the economy.”

Another use for thermometers: Drinking coffee hotter than 149F ‘probably’ causes cancer or means you’re dumb

Posted on by
Reply

Drinking coffee, tea and other beverages at temperatures hotter than 149 degrees Fahrenheit may lead to cancer of the esophagus, the World Health Organization reported Wednesday.

bill.murray.coffeeBeverages that are too hot can injure cells in the esophagus and lead to the formation of cancer cells, said Mariana Stern, an associate professor of preventative medicine and urology at the University of Southern California’s Keck School of Medicine.

But a cup of joe at the right temperature might not be so dangerous, and it could even be beneficial. Scientists said coffee at cooler temperatures is safe to drink and may decrease the risk of liver cancer by 15%, according to the research published in Lancet Oncology on Wednesday. Previously, the International Agency for Research on Cancer ruled coffee was a “possibly carcinogenic” in 1991.

“This gets the word out for more people to be aware that coffee is a healthy beverage and that it’s part of a healthy diet,” National Coffee Association President Bill Murray (right, not exactly as shown) said. “It’s an opportunity for people to drink a little more coffee and create more business.”

The research involved Stern and 22 other scientists from 10 countries, who examined about 1,000 studies on more than 20 types of cancer. They determined that drinking very hot beverages are “probably carcinogenetic,” with a higher risk of developing cancer of the esophagus.

Denmark represent: Global figures for the burden of foodborne disease

Posted on by
Reply

My friend Miriam Meister, along with Heidi Kornholt, write that every year, one-in-ten people around the world gets sick from food they eat and 420,000 die as a result.

vomit.toiletThis is the finding of a report from the World Health Organization, WHO, which uncovers the global burden of foodborne disease. Researchers from the National Food Institute, Technical University of Denmark, have contributed considerably to the project.

Knowledge about the burden of foodborne disease is crucial when setting public health targets, prioritizing resources and assessing the impact of these diseases on public health and the economy.

Statistics on foodborne disease only show the tip of the iceberg because few people go to the doctor when they get sick from something they have eaten. Over the past decade, WHO has worked to produce data that can correct for underreporting and underdiagnosis and thereby reveal the true burden of foodborne disease. This work has been carried out with the help of researchers from around the world, including researchers from the National Food Institute, who have contributed with significant input.

The project shows that within one year, one in ten people globally get sick from food they eat and of these, 420,000 end up dying.

Foodborne diseases affect people of all ages, but children are particularly at risk. WHO’s new figures show that a third of deaths related to unsafe food occur among children under five, although this age group is less than one tenth of the world’s population.

The report also shows regional differences and reveals that both cases of foodborne disease and mortality rates as a consequence thereof are higher in Africa and Southeast Asia.

Researchers from the National Food Institute has been part of an international research team, that has calculated the number of cases of disease and deaths caused by nine bacteria, viruses and parasites, which are commonly transmitted through food and typically cause diarrhea.

Researchers from the National Food Institute have also led a global study to estimate, how big a proportion of these diseases that is directly linked to food consumption. Results are presented at both global and regional level.

WHO estimates 420,000 deaths due to foodborne illness annually

Posted on by
Reply

1 in 10 people worldwide annually and 420,000 deaths (125,000 of whom are kids). That’s a lot.

WHO released these numbers it in a report published in PLOS Medicine today.who-logo1

Almost one third (30%) of all deaths from foodborne diseases are in children under the age of 5 years, despite the fact that they make up only 9% of the global population. This is among the findings of WHO’s Estimates of the global burden of foodborne diseases – the most comprehensive report to date on the impact of contaminated food on health and wellbeing.

The report, which estimates the burden of foodborne diseases caused by 31 agents – bacteria, viruses, parasites, toxins and chemicals – states that each year as many as 600 million, or almost 1 in 10 people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including 125 000 children under the age of 5 years.

“Until now, estimates of foodborne diseases were vague and imprecise. This concealed the true human costs of contaminated food. This report sets the record straight,” says Dr Margaret Chan, Director-General of WHO. “Knowing which foodborne pathogens are causing the biggest problems in which parts of the world can generate targeted action by the public, governments, and the food industry.”

While the burden of foodborne diseases is a public health concern globally, the WHO African and South-East Asia Regions have the highest incidence and highest death rates, including among children under the age of 5 years.

“These estimates are the result of a decade of work, including input from more than 100 experts from around the world. They are conservative, and more needs to be done to improve the availability of data on the burden of foodborne diseases. But based on what we know now, it is apparent that the global burden of foodborne diseases is considerable, affecting people all over the world – particularly children under 5 years of age and people in low-income areas,” says Dr Kazuaki Miyagishima, Director of WHO’s Department of Food Safety and Zoonoses.

Diarrhoeal diseases are responsible for more than half of the global burden of foodborne diseases, causing 550 million people to fall ill and 230 000 deaths every year. Children are at particular risk of foodborne diarrhoeal diseases, with 220 million falling ill and 96 000 dying every year.

 

 

 

World food safety increases risks and prevention opportunities

Posted on by
1

There was this time, about five years ago, when the U.S. Department of Agriculture decided to consult with everyone they could find to chat about food safety messaging.

who.factors(1)I participated in good faith, but soon dropped out, because it was apparent the folks in charge had their minds made up, and my – and dozens of others – time on the phone was a consultative circle jerk.

The result was those embarrassing Ad Council ads with a pig in a sauna.

I was vocal, saying that cook, clean, chill, separate places too much blame on the consumer and doesn’t account for choosing safety: source food from verifiable safe sources.

Nope, weren’t having any of that, even though the World Health Organization has been promoting that message for 15 years (one of my former students worked on this, years ago).

On World Health Day 2015, WHO/Europe estimates that levels of foodborne disease are much higher than currently reported and underlines the need for improved collaboration among sectors to lower the health risks associated with unsafe food. 

Our food chain is longer and more complex than ever before, and demographic, cultural, economic and environmental developments – globalized trade, travel and migration, an ageing population, changing consumer trends and habits, new technologies, emergencies, climate change and extreme weather events – are increasing foodborne health risks. 

“The fact that we significantly underestimate how many people become ill from chemicals in the food chain and from common microorganisms such as Salmonella and Campylobacter should start alarm bells ringing across the many areas with a stake in our food chain. A failure in food safety at any link in this chain, from the environment, through primary production, processing, transport, trade, catering or in the home, can have significant health and economic consequences,” says Dr Zsuzsanna Jakab, WHO Regional Director for Europe.

the-who-whos-next-cover*Contamination from a single source may become widespread and have enormous health and economic consequences. In 2011, for example, an enterohaemorrhagic Escherichia coli (EHEC) outbreak in Germany and France, linked to imported contaminated fenugreek seeds, led to almost 4000 cases of EHEC infection in 16 countries, including more than 900 haemolytic uraemic syndrome (HUS) cases and 55 deaths. The estimated loss for farmers and industries was US$ 1.3 billion.

*Changes in animal food production are leading to an increase in the emergence and spread of zoonotic diseases. Of 335 emerging infectious disease events in humans between 1940 and 2004, it is estimated that 60% were transmitted from animals and many of these were foodborne. 

WHO calls on policy-makers:

*To build and maintain adequate food safety systems and infrastructures, including laboratory capacities and surveillance and reporting systems; 

*To respond to and manage food safety risks along the entire food chain, including during emergencies;

*To foster multisectoral collaboration among public health, animal health, agriculture and other sectors for better communication, information sharing and joint action;

*To integrate food safety into broader food policies and programmes (e.g. nutrition and food security);

*To think globally and act locally to ensure that food produced domestically is as safe as possible internationally.

who.throws.a.shoeWorld Health Day 2015, celebrated on 7 April, is an opportunity to recognize the important food safety role of all those involved in food production, and to strengthen collaboration and coordination among these various areas, in order to prevent, detect and respond to foodborne diseases efficiently and cost-effectively. A kaleidoscope of events is planned across the globe. 

People are also invited to engage through social media and to promote “From farm to plate: make food safe” using the hashtag #safefood.

The World Organisation for Animal Health (OIE) says to be able to meet the demand for milk, eggs and meat and guarantee their safety, it is first of all essential to control pathogens in animals on the farm.

Eliminating or controlling food hazards at source has proved more effective than an approach relying solely on checking the finished product.

 

Listeriosis and Produce: What’s the Connection? (via The Abstract)

Posted on by
Reply

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 on April 7– which is focused this year on food safety. Here’s a post on Listeria’s history with produce by Danisha Garner, a graduate student in NC State’s Department of Food, Bioprocessing and Nutrition Sciences.

In the United States and other industrialized nations, consumption of fresh fruits and vegetables is considered a key component of a healthy diet.

There are many benefits to eating fresh produce such as receiving adequate vitamins and minerals, reducing the risk of heart disease, lowering blood pressure, and preventing some types of cancer. Even healthy foods, however, can be vehicles for foodborne pathogens. Indeed, fresh produce is now considered a major contributor to human foodborne disease, and an increasing number of produce-associated foodborne disease outbreaks have occurred in recent years.

An especially worrisome trend is the increase in outbreaks of listeriosis, involving the pathogen Listeria monocytogenes.

Danisha Garner. Photo courtesy of Danisha Garner.

What Is Listeriosis?

Although it is relatively uncommon, human listeriosis remains a major public health concern due to high hospitalization and death rates. In fact, it has the highest hospitalization rate of all foodborne pathogens in the U.S. and is the third largest contributor to deaths from foodborne illness. Symptoms of infection can be severe and include septicemia, meningitis, stillbirths and abortions. At high risk are the elderly, pregnant women and their fetuses, and patients with cancer and other immunocompromising conditions.

L. monocytogenes can be found in decaying plant material, soil and water, and has been detected on many types of fresh produce. Its reservoirs in nature remain poorly characterized but likely include soil and vegetation. Major contributors to the ability of L. monocytogenes to contaminate foods include its capacity to persistently colonize the environment and equipment of both food processing plants and produce packing sheds, and to grow even at refrigeration temperatures. Hence, foods typically implicated in human listeriosis are those that are processed, cold-stored and ready-to-eat – i.e. consumed without further treatment.

History of Listeriosis Outbreaks

The first outbreak of human listeriosis to be epidemiologically investigated (and to confirm foodborne transmission of the pathogen) involved produce (coleslaw) and took place in the Maritime Provinces of Canada in 1981. However, most subsequent outbreaks involved dairy products (especially soft cheeses) and ready-to-eat meats. Fresh produce was generally considered at low risk for listeriosis.

This situation changed dramatically in 2011, when one of the largest listeriosis outbreaks on record was traced to contaminated whole cantaloupe and resulted in a total of 147 cases of illness and 33 deaths across 28 states. This was also the first time that whole cantaloupe was found to serve as food vehicle for listeriosis. Contamination of the cantaloupes occurred in the packing facility, likely due to inadequate cleaning and sanitation of equipment. The pathogen was not recovered from the field where the melons were grown or from fruit prior to packing.

Even though additional melon-associated outbreaks of listeriosis have not been noted since the 2011 outbreak, several other produce-associated outbreaks have been documented in the U.S. since 2010. Implicated produce included diced celery (2010), sprouts (2014) and commercially produced, prepackaged caramel apples (2014). In all investigated cases, the source of contamination was the packing/processing environment or equipment. These outbreaks highlight the importance of having good sanitation practices in the packing/processing facility to prevent or reduce contamination with Listeria and other pathogens.

Research and Prevention

At NC State, several efforts are being focused on characterizing Listeria-produce associations with the ultimate goal of identifying new tools and strategies to reduce the risk of contamination.

In the Department of Food, Bioprocessing and Nutrition Science, researchers in the lab of Sophia Kathariou are collaborating with Lisa Gorski and William G. Miller at USDA-ARS to investigate genes of L. monocytogenes that mediate the pathogen’s adherence and growth on both fresh produce and on surfaces likely to be encountered in packing sheds and processing plants.

In collaboration with Christian Melander (in NC State’s Department of Chemistry) the Kathariou lab is also investigating the potential of novel compounds to prevent or disperse biofilms formed by L. monocytogenes on environmental surfaces and equipment. Such research will be critically needed for development of novel tools and strategies to ensure the safety of fresh produce and reduce the risk for human listeriosis.

More information about Listeria monocytogenes and listeriosis outbreaks can be found at http://www.cdc.gov/listeria/