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)
More than half of the severe listeriosis cases in the European Union belong to clusters, many of which are not being picked up fast enough by the current surveillance system, suggests a new article published in Eurosurveillance.
The large-scale study looked into listeriosis epidemiology through whole genome sequencing and found that this method, when implemented at EU-level, could lead to faster detection of multi-country outbreaks, saving up to 5 months of the investigations.
The study, coordinated by the European Centre for Disease Prevention and Control (ECDC), analysed 2 726 human Listeria monocytogenes isolates from 27 countries between 2010 and 2015.
It found that slightly under 50% of the cases are isolated whereas the remaining half of cases is clustered together. Around one third of the cases that were identified as part of a cluster affected more than one country, often lasting for several years. However, only two listeriosis outbreaks were reported in the EU in 2016 and five in 2015, which suggests that many of them have gone undetected.
The authors determined that the use of whole genome sequencing to characterise listeriosis cases at EU-level could speed up the detection of clusters by up to five months, when compared to epidemiological investigation at country level. A more timely detection of clusters would potentially limit the occurrence of further cases from the same, common food source.
“This study is a milestone on the way to tackling listeriosis in Europe. With this new collaborative effort with the Member States, we have revealed the related nature of many cases of severe listeriosis. We are now strengthening routine surveillance by introducing the collection and analysis of whole genome sequencing data from all reported human listeriosis cases”, says ECDC’s Chief Scientist Mike Catchpole.
Listeriosis is a relatively rare but potentially severe food-borne disease that has been reported in increasing numbers in the EU/EEA countries since 2008. In 2016, 2 536 cases were reported, including 247 deaths. “Improving our surveillance on Listeria cases will save lives, particularly among vulnerable population groups such as the elderly and also pregnant women, who may pass on the bacteria to the fetus if they consume contaminated food”, Mike Catchpole points out.
The study also defines the most appropriate typing methods for earlier detection and investigation of dispersed cross-border clusters and outbreaks of Listeria monocytogenes.
On 2 May 2018, Denmark reported a cluster of hepatitis A virus (HAV) infections with the subgenotype IA strain DK2018_231, through the European Centre for Disease Prevention and Control (ECDC)’s Epidemic Intelligence Information System (EPIS) for food- and waterborne diseases and zoonoses (FWD).
One of the three confirmed cases had travelled to Morocco. In response, five additional European Union (EU) countries (France, Germany, the Netherlands, Spain and the United Kingdom (UK)) reported cases (n = 20) infected with the same strain between 21 January and 10 April 2018.
Concurrently, Germany reported to EPIS that it observed more cases of hepatitis A with travel history to Morocco than expected, compared with the same period in the previous 5 years. Molecular analysis of the HAV VP1/P2A region revealed an unrelated cluster of the HAV subgenotype IB strain V18–16428. Cases infected with this unrelated strain were also reported from France, the Netherlands, Sweden and UK.
The appearance of clusters with a link to Morocco triggered further epidemiological investigations.
Two concurrent outbreaks of hepatitis A highlight the risk of infection for non-immune travelers to Morocco, January to June 2018
Martyna Gassowski, Kai Michaelis, Mirko Faber, Julie Figoni…
Listeriosis affected about 2,200 people in 2015, causing 270 deaths – the highest number ever reported in the EU. The proportion of cases in the over 64 age group steadily increased from 56% in 2008 to 64% in 2015. Additionally, in this period, the number of reported cases and their proportion has almost doubled in those over 84 years.
“It is concerning that there continues to be an increasing trend of Listeria cases which mostly occur in the elderly population. ECDC is working together with Member States to enhance surveillance for food- and waterborne diseases, starting with Listeria, as earlier detection of relevant clusters and outbreaks can help prevent further cases,” said Mike Catchpole, Chief Scientist at ECDC. “This is a public health threat that can and needs to be addressed”, he added.
Dr. Marta Hugas, Head of Biological Hazards and Contaminants at EFSA, said: “Listeria seldom exceeded the legal safety limits in ready-to-eat foods, the most common foodborne source of human infections. However, it is important that consumers follow manufacturers’ storage instructions and the guidelines given by national authorities on the consumption of foods.”
In 2015, there were 229,213 reported cases of campylobacteriosis. This disease remains the most commonly reported foodborne disease in the EU, showing an upward trend since 2008. Campylobacter is mostly found in chickens and chicken meat.
The number of cases of salmonellosis, the second most commonly reported foodborne disease in the EU, increased slightly – from 92,007 in 2014 to 94,625 in 2015. The increase observed in the past two years is partly due to improvements in surveillance and better diagnostic methods. However, the long-term trend is still declining and most Member States met their Salmonella reduction targets for poultry populations.
Salmonella is mainly found in meat (poultry) intended to be cooked before consumption.
The overall aim for these EQA schemes was to enhance the European surveillance of food-borne pathogens by evaluating and improving the quality and comparability of molecular typing. The EQAs were organised by Statens Serum Institut (SSI) and included Salmonella enterica subsp. enterica, verocytotoxin-producing Escherichia coli (VTEC) and Listeria monocytogenes. Inter-laboratory comparable pulsed-field gel electrophoresis (PFGE) images were obtained from 10 of 17 of the participating laboratories for Listeria, 15 of 25 for Salmonella, but only nine of 20 for VTEC. Most problems were related to PFGE running conditions and/or incorrect use of image acquisition. Analysis of the gels was done in good accordance with the provided guidelines. Furthermore, we assessed the multilocus variable-number tandem repeat analysis (MLVA) scheme for S. Typhimurium. Of 15 laboratories, nine submitted correct results for all analysed strains, and four had difficulties with one strain only. In conclusion, both PFGE and MLVA are prone to variation in quality, and there is therefore a continuous need for standardisation and validation of laboratory performance for molecular typing methods of food-borne pathogens in the human public health sector.
Evaluation of molecular typing of foodborne pathogens in European reference laboratories from 2012 To 2013
Eurosurveillance, Volume 21, Issue 50, 15 December 2016
S Schjørring, T Niskanen, M Torpdahl, JT Björkman, EM Nielsen
There were 2,161 confirmed cases of Listeriosis infections in 2014, a rise of 16% compared with 2013. Although the number of cases are relatively low, the rise of reported listeriosis cases is of particular concern as the surveillance of these infections is focused on severe forms of the disease, with higher death rates than for other foodborne diseases, particularly among the elderly, and patients with a weak immune system.
Campylobacteriosis remains the most commonly reported food-borne disease in the EU and has been so since 2005. The number of confirmed cases in the EU in 2014 was 236,851, an increase of 10%, compared with 2013. This increase can partly be explained by improvements in the surveillance system and/or improved diagnostics for campylobacteriosis in several Member States. In food, Campylobacter was mostly found in chicken meat.
Confirmed cases of salmonellosis, the second most commonly reported food-borne disease in the EU, increased slightly for the first time over the period 2008–2014, due to changes in the number of Member States reporting. However, there has been a statistically significant downward trend of salmonellosis in the seven-year period of 2008–2014. This is mainly due to the successful Salmonella control programmes put in place for poultry by EU Member States and the European Commission.