Vibrio in seafood goes up

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.

Vibrio 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; xi
  • 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;
  • 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


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

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 


FAO: Fueled by aquaculture, fish consumption reaches all time high

The world is eating more fish than ever and contrary to popular notions, fish farming and not marine wild catch is meeting the global demands, the United Nations’ Food and Agriculture Organization’s (FAO) State of World Fisheries and Aquaculture 2016 report has revealed. FAO brings out this report every two years. It said that India is one of 35 countries that produced more farmed than wild-caught fish in 2014. According to the report, almost 90 per cent of aquaculture production takes place in Asia, most of it in the tropical and subtropical belts.

fish1In the exhaustive report, encapsulating the trends of world fishing production, it has come to light that diversified production has increased the average per capita availability to a new high of more than 20kg. “World per capita apparent fish consumption increased from an average of 9.9 kg in the 1960s to 14.4 kg in the 1990s and 19.7 kg in 2013, with preliminary estimates for 2015 indicating further growth, exceeding 20 kg,” the report said.

Globally, total capture fishery production in 2014 was 93.4 million tonnes, of which 81.5 million tonnes from marine waters and 11.9 million tonnes from inland waters. In 2014, there were an estimated 4.6 million fishing vessels with Asia alone having 3.5 million of them and 64 per cent of global vessels were engine-powered.


Insects as food: Potential hazards and research needs

The consumption of insects or eat bugs, is a common practice in some parts of the world (Africa, Asia, Latin America), where it may become part of the traditional food culture.

thai.insects.foodTo meet the challenge of feeding the world in 2030, the United Nations Food and Agriculture Organization (FAO) has ruled in favor of the development of large-scale breeding insects. In anticipation of a possible development of these products in Europe or France, ANSES has made ​​an inventory of scientific knowledge on the risks associated with the consumption of insects. In its opinion published today, it makes an inventory of potential dangers carried by insects and research needs on this issue. Following this work, it recommends in particular to establish at Community level lists of species that can be consumed and to define a specific framework for breeding and production conditions of insects and their products, to ensure the control of health risks. Moreover, many insects and arthropods (mites, crustaceans, molluscs, etc.) With common allergens, ANSES recommends caution consumers with a predisposition to allergies.

The consumption of insects or eat bugs, is a common practice in some parts of the world (Africa, Asia, Latin America), where it may become part of the traditional food culture. FAO estimates that “insects complement the diets of about two billion people” in the world and in favor of the development of the breeding of insects on a large scale to meet the growing concerns over food security and protein supply.

In Europe, this practice seems to benefit from a growing interest and a number of industrial projects and research programs accompany this emerging sector, despite regulations (currently changing), which raises many questions.

In this context, ANSES has conducted an inventory of scientific knowledge on the subject, in particular regarding the potential health risks associated with consumption of insects and insect products, both food and feed.

Like all foods, insects can carry certain risks that must be controlled by the setting of specific standards to reduce the potential risks associated with the consumption of these products.

These hazards are mainly related:

to chemicals (poisons, anti-nutrients, veterinary drugs used in farming insects, pesticides or organic pollutants in the environment or insect feeding, etc.).

physical agents (hard parts of the insect sting like the rostrum, etc.).

to common allergens to all arthropods (mites, crustaceans, molluscs, etc.).

to parasites, viruses, bacteria and their toxins or fungi.

to breeding and production conditions for which should be defined specific supervision to ensure the control of health risks.

Moreover, in general, like other foods of animal or plant origin, edible insects may become, following an unsuitable preservation, unfit for human consumption.

The expert work of the Agency stresses the need for further research to conduct a full assessment of the health risks associated with consumption of insects. Furthermore, the development of such production chains insects from breeding to slaughter, should lead to the question of animal welfare, it has so far been little explored in most invertebrates.

The recommendations of the handles

In this context of uncertainty and lack of data, the Agency recommends:

accentuate the research effort on the sources of potential hazards;

to establish, at Community level, the positive and negative lists of different species and insect life stages may or may not be eaten;

to explore the issue of animal welfare for these categories of invertebrates;

to define a specific framework of the breeding and production of insects and their products to ensure the control of health risks;

setting allergic risk prevention measures, both for consumers and in the workplace.

Pending the establishment of specific standards and appropriate supervision, ANSES recommends caution consumers with a predisposition to allergies. Indeed, many insects and arthropods (mites, crustaceans, molluscs, etc.) Have common allergens.

Beyond the issues of expertise specifically associated with health risk assessment issues and nutritional benefits relating to the consumption of insects, ANSES emphasizes the strong knowledge of issues relating to the social acceptability of these new drinks or on issues of development and environmental impact associated with it.

UN agency says surge in diseases of animal origin means new approach to health needed

Holistic is a term academics and those on the conference circuit like to toss around when they have no idea how to actually improve things.

Or sometimes it’s just the PR types who write the fluff.

According to a new report from the Food and Agriculture Organization of the United Nations, population growth, agricultural expansion, and livestockthe rise of globe-spanning food supply chains have dramatically altered how diseases emerge, jump species boundaries, and spread,

A new, more holistic approach to managing disease threats at the animal-human-environment interface is needed, it argues.

Seventy percent of the new diseases that have emerged in humans over recent decades are of animal origin and, in part, directly related to the human quest for more animal-sourced food, according to the report, World Livestock 2013: Changing Disease Landscapes.

The ongoing expansion of agricultural lands into wild areas, coupled with a worldwide boom in livestock production, means that “livestock and wildlife are more in contact with each other, and we ourselves are more in contact with animals than ever before,” said Ren Wang, FAO Assistant Director-General for Agriculture and Consumer Protection.

“What this means is that we cannot deal with human health, animal health, and ecosystem health in isolation from each other – we have to look at them together, and address the drivers of disease emergence, persistence and spread, rather than simply fighting back against diseases after they emerge,” he added.

FAO’s new study focuses in particular on how changes in the way humans raise and trade animals have affected how disease emerge and spread.

“In response to human population growth, income increases and urbanization, world food and agriculture has shifted its main focus from livestock-img01the supply of cereals as staples to providing an increasingly protein-rich diet based on livestock and fishery products,” World Livestock 2013 notes.

While livestock production provides a number of economic and nutrition benefits, the sector’s rapid growth has spawned a number of health-related challenges, it says.

The risk of animal-to-human pathogen shifts varies greatly according to the type of livestock production and the presence of basic infrastructure and services.

While intensive production systems are largely free from high-impact animal and zoonotic diseases, they do present some pitfalls, particularly in developing countries and countries in transition, according to the report.

The report also states, however, that disease emergence in livestock is not specific to large-scale, intensive systems.

Smallholder livestock systems – which tend to involve animals roaming freely over large areas, but still in relatively high densities – often facilitate the disease spread, both among local animal populations and over broad distances.

UN Food and Ag Organization endorses One Health

Safe food is food that doesn’t make people barf. Or animals.

That’s the essence of One Heath. Things that make people and animals sick.

The American Medical Association and the American Veterinary Medical Association have approved resolutions supporting ‘One Medicine’ or ‘One Health’ that bridge the two professions. Rudolf Virchow, the Father of Modern Pathology, and Sir William Osler, the Father of Modern Medicine, were outspoken advocates of the concept, which was re-articulated in the 1984 edition of Calvin Schwabe’s Veterinary Medicine and Human Health.

Today, the Food and Agriculture Organization of the United Nations said governments could save billions of dollars by stepping up the prevention and control of high impact animal diseases, some of which pose a direct threat to human health.

?Many other animal diseases have a negative impact on people’s livelihoods. Pandemic influenza viruses H5N1 and H1N1, foot-and-mouth disease, Rift Valley fever, and rabies are among the more recent disease outbreaks.

Land use, ecological dynamics including climate change, and expanding trade and trade routes are all posing new challenges to animal disease prevention and control, the UN agency warned.

These emerging threats are also related to increased urbanization and strongly growing urban demand for meat, milk and eggs. A rapid increase and intensification in poultry, production in East Asia translated into a five-fold increase in duck meat output between 1985 and 2000. In 2008, over 21 billion animals were produced for food globally, a figure expected to rise by fifty percent by 2020.

FAO, in partnership with the World Organisation for Animal Health and the World Health Organization has adopted a One Health strategy to more effectively detect and combat these new pathogens.

Drawing on the agency’s experience in past animal health emergencies, the One Health initiative aims to make a key contribution to the global response to disease outbreaks, implementation of effective prevention and containment strategies and management of risks of disease emergence, including improving knowledge of disease-emergence drivers in livestock production and in associated ecosystems.

Special attention of the programme is given to risk communication at all levels of action.