Foodborne diseases do not respect borders
: The prevalence of foodborne zoonotic bacteria in imported products of animal origin into the European Union

  • Wiebke Jansen

Student thesis: Doc typesDoctor of Veterinary Sciences


Globalisation, international travel and trade and the ever-growing flow of goods and people enable zoonotic pathogens to spread worldwide. People and goods move faster than the incubation period of the pathogens they carry. Foodborne zoonoses are of a particular public health concern due to their significant morbidity and mortality rates. The risk to introduce or re-introduce foodborne zoonotic bacteria into the European Union is omnipresent as considerable amounts of food products of animal origin from endemic countries are continuously imported, both legally and illegally. Serious zoonoses such as brucellosis are re-emerging, although eradicated from livestock in most Member States of the European Union. Considerable numbers of domestic human brucellosis cases have been reported annually in non-endemic countries, but the actual source of these autochthonous cases remains to be elucidated.

This thesis comprises pieces of research on the legal background of veterinary public health measures and regulations. The epidemiological studies analysed legally and illegally imported meat and cheese for major foodborne zoonotic pathogens and food hygiene indicator bacteria with a special emphasis on Brucella spp.. The rapid alternative method fluorescence in situ hybridization was developed for the detection of Brucella spp. in milk and cheese.

Though the import of meat, milk and products therefore by private travellers is banned due to harmonised regulations in the European Union, particularly airports served as major hubs for those illegal imports. Raw products embraced specifically food safety risks. Raw Egyptian poultry was significantly contaminated with foodborne zoonotic pathogens. Illegally imported sausages and cheese pose mainly a food hygiene risk, as critical values for microbiological market requirements were frequently exceeded.

In contrast, most legal imports are dispatched in sea ports as entry points of the European Union. Legal meat imports complied in the vast majority of imported consignments with market requirements, only negligible quantities of poultry meat were unacceptable due to microbiological contamination. However, uncommon and genetically distant variants including antimicrobial resistant foodborne pathogens such as methicillin-resistant Staphylococcus aureus or extended-spectrum β-lactamase-producing Enterobacteriaceae were discovered in both legal and illegal meat imports.

Legally imported cheese did not comply with food safety standards. A particular public health concern was raw milk cheese from endemic countries, available on retail level, which were proven to harbour Brucella spp.. The alternative method fluorescence in situ hybridization enabled the determination of occurrence, viability and distribution of Brucella spp. in milk and cheese.

The most likely cause of zoonotic pathogens in imported meat are cross contamination and improper hygiene measures while handling, processing and storage. Brucella-positive raw milk cheese available at German retail level results in a possible re-emerge of brucellosis as a foodborne zoonosis in non-endemic countries due to uncontrolled imports.

The pieces of research settled in this thesis narrow an important knowledge gap. The importance of import controls was highlighted and it was shown that primarily globalised travel accelerates and intensifies the transmission and spread of food safety and food hygiene risks globally. Moreover, these quantitative descriptions of foodborne pathogens and the resulting prevalences will serve for the effectiveness analyses of surveillance, control and intervention methods of foodborne pathogens in the European Union and are simultaneously essential inputs for mathematical models in burden of disease studies and risk assessments for import risk analysis.
Date of Award19 Mar 2019
Original languageEnglish
Awarding Institution
  • University of Namur
SponsorsUniversity of Namur
SupervisorBenoit Muylkens (Supervisor), Xavier De Bolle (President), Sascha Al Dahouk (Jury), Martine Raes (Jury), Marcella Mori (Jury), Rixta Lycklama à Nijeholt (Jury) & Anne Vermeylen (Jury)

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