The trend in infections and diseases transmitted from animals to humans, especially through food, is shown in the One Health 2022 report prepared by EFSA (European Food Safety Authority) and ECDC (European Center for Disease prevention and Control). (1)
Campylobacteriosis and salmonellosis are confirmed as the most widespread zoonoses in the EU, followed by yersiniosis, STEC infections and listeriosis. The latter and West Nile virus infection are the two most serious diseases, with the highest mortality and hospitalization rates.
The 64 cases of premature mortality caused by foodborne diseases in 2022 mark a ten-year record and derive mainly from Listeria monocytogenes. To a lesser extent, also from Salmonella.
1) One Health 2022, Campylobacter at the top of the ranking
Among human cases confirmed zoonoses, Campylobacter confirms itself as the undisputed protagonist, already since 2005. It is the subject of over 137 thousand reports (61,3% of the total) in 2022, with a summer peak and over 10 thousand hospital admissions.
This infective gastrointestinal disease of food origin is contracted above all with the consumption of raw or undercooked poultry meat (chicken and turkey), raw or undercooked pork meat, raw milk and oysters.
1.1) Prevention and complications
The Campylobacter bacteria Campylobacter are inactivated by cooking at at least 70°C for two minutes. (2)
'As a pathogen that is primarily transmitted through contaminated food, Campylobacter is constantly exposed to antimicrobials used in food production environments. In response to this selective pressure, it has developed resistance to several classes of antimicrobials, becoming a serious public health problem. Although the presence of multidrug-resistant strains is still rare in humans, their numbers are increasing among livestock populations in some countries., warns EFSA. (3)
2) Salmonella
Salmonellosis is the second most commonly reported food-borne gastrointestinal infection in humans in the European Union. The 65.208 cases confirmed in 2022 mark a stable trend, with a slight increase in hospital admissions (38,9%).
'Salmonella is a genus of highly diverse bacteria which live in the intestinal tract of humans and animals and are widespread in the environment thanks to ability to survive and adapt even in extreme conditions', EFSA explains. (4)
It persists in fact in the soil, in water and on surfaces. And it is hosted by various animals, including domestic ones. (5)
2.1) How salmonellosis is contracted
Salmonellosis can be contracted through:
– consumption of contaminated food or water (foodborne infection),
– contact with infected animals, including pets, such as dogs and cats, but also amphibians and reptiles,
– person-to-person transmission, due to contact with contaminated materials, such as toilets and diapers, without washing hands.
Foods at greatest risk of contamination are:
- eggs,
– meat and meat products, mainly chickens and pigs,
- fruits and vegetables,
– raw milk and dairy products made from raw milk,
- seafood products,
- spices,
– processed foods, such as baked goods, sweets and chocolate (remember the outbreak of over 100 cases triggered by Kinder Ferrero). (6)
Kids, elderly, immunocompromised, pregnant women are at greater risk. The disease manifests itself with diarrhea lasting two to seven days, also accompanied by fever, abdominal cramps, vomiting and dehydration.
Prevention requires measures such as cooking at least 70°C at the core of the food and correct handling of kitchen utensils. (7)
Campylobacter antimicrobial resistance, like that of some strains of Salmonella, is also dangerously increasing. (8)
3) Yersiniosis
Yersiniosis is the third most commonly reported food-borne gastrointestinal infection in humans in the European Union in 2022, with 7.919 cases (+16,3% compared to 2021).
Traditionally associated with the consumption of undercooked pork products and unpasteurized milk, it is also spreading to ready-to-eat vegetables eaten raw.
3.1) Yersinia, the three species
'Yersinia is a genus of bacteria that belongs to the Enterobacteriaceae family, and includes numerous species widely spread in the environment.
The species capable of causing disease there are three in both animals and humans:
- Y. enterocolitica is responsible for cases of enteritis in various animal species such as non-human primates, chinchillas, guinea pigs, domestic pigs, wild boars, deer, dogs and cats. In the European Union it is the species most frequently associated with cases of human infection. The pig is considered the main reservoir and the pork and derivatives are believed to be the main source of infection; although it has also been isolated from other foods such as red meat, milk and vegetables. Pathogenic Yersinia enterocolitica is capable of causing a wide spectrum of clinical manifestations in humans, starting from enteric infections self-limiting until you get to severe septicemia. The most common symptoms are diarrhea (sometimes bloody), especially in children under 5 years of age, while in adults the symptoms of pseudo-appendicitis (right abdominal pain and fever) are more frequently observed;
– Y. pestis is the causal agent of plague in humans, a disease no longer present in Europe and transmitted by the bite of the rat flea;
– Y. pseudotuberculosis is responsible for diffusive diseases in numerous animal species and humans. The species considered susceptible belong to the class of mammals (rodents, non-human primates, hedgehogs, hares, domestic dogs, ruminants, bats, pigs and felines), birds (guinea fowl, turkey, canary), and finally gods reptiles and fish. In humans, enteric infections associated with Y. pseudotuberculosis have been reported mainly in Northern European countries and Russia', explains the Istituto Zooprophylattico Sperimentale delle Venezie. (9)
4) STEC
STEC, Shiga-toxin producing Escherichia coli, are the most dangerous strains of the bacterium Escherichia coli. In fourth place in the ranking of food poisonings registered in the European Union in 2022 with 7.117 cases, 1.130 hospitalizations and 28 deaths. The most dramatic outbreak – one adult and 55 children, two of whom died – was caused by Buitoni's Fraîch'Up pizza. (10,11)
STEC infections are characterized by diarrheal episodes sometimes complicated by intestinal bleeding (haemorrhagic colitis). And in the most serious cases, kidney acute failure. (12)
4.1) Routes of human infection
The risk of infection for humans is related to:
– consumption (or handling) of contaminated food or water (food- and water-borne infection),
– contact with infected animals and/or their excrement,
– contact with a contaminated environment,
– person-to-person contact (fecal-oral human-to-human transmission).
Foods at risk for STEC are:
– contaminated meat (mainly beef), due to inadequate processing methods during slaughter,
– milk contaminated during milking without respecting hygiene standards and cheese produced with such milk,
– vegetables, fruits, sprouts and seeds fertilized and irrigated with contaminated manure and water,
– private well water contaminated with feces and not subjected to chlorination,
– food contaminated directly by people preparing meals who do not follow adequate hygiene measures. (13)
4.2) The missing prevention
The presence of STEC in the intestines of animals could be controlled through strategies such as
– vaccination,
– the administration of bacteriophages (viruses that infect and replicate only in bacterial cells),
– changes in nutrition and administration of probiotics.
5) Listeriosis
The 2.738 human cases di Listeria monocytogenes reported by the 27 Member States in 2022 resulted in 1.330 hospital admissions and 286 deaths.
Listeriosis is the fifth most reported zoonosis in the European Union. It is one of the most serious and subtle food-borne illnesses, with incubation periods of up to three months. The mortality rate in 2022 was high (18,1%), higher than that of 2021 and 2020 (13,7% and 13% respectively).
L. monocytogenes is a ubiquitous and very resistant bacterium. The risk of contamination may occur in meat-based preparations and products (cured meats), fish products (i.e. smoked salmon), unripened raw milk cheeses, but also in Ready-To-Eat foods (RTE).
5.1) A fearsome super bacterium
These bacteria are widespread in the environment and tolerate extreme conditions: acidic, dry and salty, with or without oxygen. They also multiply in refrigerated foods. (14)
Senior citizens, children, pregnant women, immunocompromised people are at greater risk of negative evolutions of the disease, which manifests itself in the form of acute febrile gastroenteritis but also in more serious forms that degenerate into septicemia or infections of the nervous system (meningitis) and various outcome complications even lethal, as we have seen. (15)
5.2) Listeria monocytogenes and 'food cultures', the European paradox
The 'food cultures' – cultures of microorganisms used for millennia in the preparation of various foods – have proven to be the most effective solution to guarantee their microbiological stability and inhibit Listeria monocytogenes. An extremely natural solution, useful for reducing and/or eliminating nitrite preservatives which instead have contraindications for human health.
The European Commission – instead of promoting and recommending the use of this precious solution in all supply chains at risk of contamination by the killer bacterium – is instead following up on a proposal from the Dutch government to subject 'food cultures' to the food additive regime. With the real risk of interrupting a virtuous path of protecting public health. (16)
6) West Nile virus infection
In 2022 1.133 cases of West Nile virus (WNV) infection were reported, with an increase of +638,8% compared to the previous year, as a consequence of an epidemic outbreak in Greece and Italy.
The data report nearly 600 cases of neuroinvasive disease and 92 deaths.
6.1) Virus transmitted by mosquitoes
West Nile Disease (WND, or West Nile Fever) is a zoonosis caused by a arbovirus belonging to the family flaviviridae.
The natural reservoir is represented by wild birds. The virus is transmitted by mosquitoes (Culicides) and can infect birds, horses and humans.
7) Conclusions
The EFSA and ECDC's One Health report shows the results of zoonoses monitoring and surveillance activities conducted in 2022 in 27 Member States (MS), the United Kingdom (Northern Ireland) and 11 non-MS countries.
However failure or partial provision of data by numerous countries undermines the reliability of the report, generating under-reporting which, in fact, prevents coordinated management of the prevention of zoonoses in the EU.
Marta Strinati and Dario Dongo
Footnotes
(1) The European Union One Health 2022 Zoonoses Report. European Food Safety Authority (EFSA), European Center for Disease Prevention and Control (ECDC). 12 December 2023 https://doi.org/10.2903/j.efsa.2023.8442
(2) Dario Dongo, Silvia Bonardi. Campylobacter, beware of undercooked poultry and pork. GIFT (Great Italian Food Trade).
(3) Story Map on Campylobacter. EFSA (European Food Safety Authority), 2022. https://storymaps. arcgis.com/stories/37987745de6f47029e14cb57d61fe923
(4) Story map on Salmonella. EFSA (European Food Safety Authority), 2022. https://storymaps. arcgis.com/stories/13979918ca8948399180651d3b7ce3e1
(5) Silvia Bonardi, Dario Dongo. Salmonella, the most common pathogen in Europe, ABC. GIFT (Great Italian Food Trade).
(6) Marta Strinati. The Belgian Authority closes the Ferrero factory for suspected cases of salmonella linked to Kinder. GIFT (Great Italian Food Trade).
(7) Marta Strinati. A perfect barbecue against food poisoning. GIFT (Great Italian Food Trade).
(8) Marta Strinati. Salmonella and Campylobacter increasingly resistant to antibiotics. GIFT (Great Italian Food Trade).
(9) Yersiniosis. Experimental Zooprophylactic Institute of Venice (IZSVe) https://www.izsvenezie.it/temi/malattie-patogeni/yersiniosi/
(10) Investigation of group cases of hémolytique et urémique syndrome (SHU) and infections of E. coli shiga-toxin products (STEC) in connection with the consumption of Fraîch'Up pizzas of the Buitoni® brand. Point de situation au 4 mai 2022. Santé publique France. 10.5.22 https://www.santepubliquefrance.fr/les-actualites/2022/investigation-de-cas-groupes-de-syndrome-hemolytique-et-uremique-shu-et-d-infections-a-e.-coli-producteurs-de-shiga-toxine-stec-en-lien-avec-la3
(11) Marta Strinati. Pizza Fraîch'Up, the Nestlé Buitoni factory was a time bomb. GIFT (Great Italian Food Trade).
(12) Silvia Bonardi, Dario Dongo. STEC in cheeses, in-depth analysis. GIFT (Great Italian Food Trade).
(13) EFSA (European Food Safety Authority), 2023. Story map on Shiga toxin-producing Escherichia coli, available online: https://storymaps.arcgis.com/stories/ff3eb57b8d40474485d533b3cd2cfa63
(14) Story map on Listeria monocytogenes. EFSA (European Food Safety Authority), 2022. https://storymaps.arcgis.com/stories/629e6627e6c64111bfd5b9257473c74a
(15) Dario Dongo. Listeria, a dangerous pathogen out of control. GIFT (Great Italian Food Trade).
(16) Dario Dongo. Natural preservatives at risk of legal barriers, short circuit in the EU. GIFT (Great Italian Food Trade).
A professional journalist since January 1995, she has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic studies on food and has published the book "Reading labels to know what we eat".
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
