Salmonellosis in Poland in 2020.

AIM: The aim of the study is to assess the epidemiological situation of salmonellosis in Poland in 2020 compared with previous years. MATERIAL AND METHODS: The epidemiological situation was assessed on the basis of data provided to the Department of Epidemiology of Infectious Diseases and Surveillance of the NIPH NIH-NRI by sanitary-epidemiological stations through the EpiBaza System and the Registry of Epidemic Outbreaks System (ROE), as well as on the basis of data published in the annual bulletin "Infectious Diseases and Poisoning in Poland in 2020" (NIPH NIH-NRI, GIS, Warsaw, 2021) and from information received from laboratories of sanitary-epidemiological stations and data from the Demographic Research Department of the Statistics Poland. RESULTS: In Poland in 2020, in the sanitary-epidemiological surveillance registered a total of 5,470 cases of salmonellosis, 5,302 cases of intestinal salmonellosis, and the remaining 168 cases of extra-intestinal salmonellosis. The incidence per 100,000 population was 14.3 for total salmonellosis, 13.8 for intestinal salmonellosis and 0.44 for extra-intestinal salmonellosis. Sanitary-epidemiological stations registered 5,349 confirmed cases and 121 probable cases of salmonellosis. Due to intestinal salmonellosis, 63.9% of all patients were hospitalized, while for extra-intestinal salmonellosis 153 patients or 91.1% of cases, were hospitalized. The increase in the number of salmonellosis cases in 2020 started in June, while the peak of the incidence was in August. Among the voivodeships, the highest incidence of salmonellosis was registered in the Podkarpackie voivodeship 33.3/100,000 population, the lowest in Zachodniopomorskie 6.1/100,000 population. Cases in the 0-4 age group accounted for 45.2% of all salmonellosis cases in 2020. Among extra-intestinal salmonellosis, 63.1% were people aged 60+. Sanitary-epidemiological stations registered 131 food poisoning outbreaks caused by Salmonella bacilli in the ROE system, 108 of these outbreaks were caused by the Enteritidis serotype. In 2020, the most common serotypes were S. Enteritidis 70% of all recorded salmonellosis, S. Typhimurium 1.9%, and S. Infantis 0.54%. There were 9 deaths due to Salmonella infection. CONCLUSIONS: The COVID-19 pandemic and the associated restrictions introduced in the country, as well as increased hygiene through more frequent washing and disinfection of hands, could have contributed to a reduction of almost 69% in the number of salmonellosis cases registered in 2020, in Poland, compared to 2019. This is a 82% decrease in relation to 2018. There was also a decrease in the number of food poisoning outbreaks caused by Salmonella bacilli, while at the same time their percentage in the total number of outbreaks increased. On the one hand, the implemented restrictions could have had an impact on the decrease in the number of cases and outbreaks, on the other hand, worse access to medical care and diagnostics, most likely deepened the underestimation of these cases in the country observed for years, and distorted the real picture of the situation.

Sources and trends of human salmonellosis in Europe, 2015-2019: An analysis of outbreak data.

Salmonella remains a major cause of foodborne outbreaks in Europe despite the implementation of harmonized control programmes. Outbreak data are observed at the public health endpoint and provide a picture of the most important sources of human salmonellosis at the level of exposure. To prioritize interventions, it is important to keep abreast of the sources and trends of salmonellosis outbreaks. The objective of this study was to determine the main food sources and recent trends of Salmonella outbreaks in Europe. Salmonella outbreak data from 34 European countries in 2015-2019 were obtained from the European Food Safety Authority (EFSA). For the source attribution analysis, implicated foods were categorized according to EFSA's zoonosis catalogue classification scheme. An established probabilistic source attribution model was applied using the information on the implicated foods, overall and by region and serotype. To assess significant trends in outbreak occurrence, overall and by region and serotype, mixed-effects Poisson models were used. Overall, the most important food source of salmonellosis outbreaks was eggs (33 %, 95 % Uncertainty Interval [UI]: 31-36 %), followed by pork (7 %, 95 % UI: 6-8 %), and (general) meat products (6 %, 95 % UI: 5-8 %). While eggs were the most important food source in all regions, pork was the second most common food source in Northern and Western Europe, and (general) meat products in Eastern and Southern Europe. Outbreaks caused by S. Enteritidis (SE) and other known serotypes (other than SE and S. Typhimurium and its monophasic variant [STM]) were mostly attributed to eggs (37 %, 95 % UI: 34-41 % and 17 %, 95 % UI: 11-25 %, respectively), whereas outbreaks caused by STM were mainly attributed to pork (34 %, 95 % UI: 27-42 %). Overall, there was a significant increase in the number of outbreaks reported between 2015 and 2019, by 5 % on average per year (Incidence Rate Ratio [IRR]: 1.05, 95 % Confidence Interval [CI]: 1.01-1.09). This was driven by a significantly increased number of outbreaks in Eastern Europe, particularly those caused by SE (IRR: 1.15, 95 % CI: 1.09-1.22), whereas in Northern and Southern Europe, outbreaks caused by SE decreased significantly from 2015 to 2019 (IRR: 0.72, 95 % CI: 0.61-0.85; IRR: 0.70, 95 % CI: 0.62-0.79, respectively). Regional, temporal and serotype-associated differences in the relative contributions of the different sources were also observed.

Impact of the COVID-19 pandemic on human salmonellosis in the Netherlands.

The public health measures implemented to control coronavirus disease 2019 (COVID-19) may influence also other infectious diseases. Using national laboratory surveillance data, we assessed the impact of the COVID-19 pandemic on human salmonellosis in the Netherlands until March 2021. Salmonellosis incidence decreased significantly after March 2020: in the second, third and fourth quarters of 2020, and in the first quarter of 2021, the incidence decreased by 55%, 57%, 47% and 37%, respectively, compared to the same quarters of 2016-2019. The decrease was strongest among travel-related cases (94%, 84%, 79% and 93% in the aforementioned quarters, respectively). Other significant changes were: increased proportion of cases among older adults and increased proportion of invasive infections, decreased proportion of trimethoprim resistance and increased proportion of serovar Typhimurium monophasic variant vs. Enteritidis. This led to decreased contributions of laying hens and increased contributions of pigs and cattle as sources of human infections. The observed changes probably reflect a combination of reduced exposure to Salmonella due to restrictions on international travels and gatherings, closure of dine-in restaurants, catering and hospitality sectors at large and changes in healthcare-seeking and diagnostic behaviours.

Microbiological analysis of frozen profiteroles and mini chocolate eclairs implicated in a national salmonellosis outbreak.

Between November 2018 and May 2019, Canada experienced a nationwide salmonellosis outbreak linked to the presence of Salmonella enterica ser. Enteritidis in frozen profiteroles. Analysis of the implicated food products revealed low levels of Salmonella ranging from 0.2 to 0.7 MPN/100g. Water activity and pH of the food samples ranged from 0.9479 to 0.9867 and 4.6-6.8 respectively indicating conditions conducive to bacterial growth. Higher levels of the hygiene indicators Enterobacteriaceae and coliforms were associated with Salmonella positive samples compared to Salmonella negative samples. Investigation of the relationship between storage conditions, temperature, and pathogen levels during thawing revealed that the profiteroles reached temperatures permissive to pathogen growth (≥5 °C) much sooner than pathogen growth was observed and that the composition of the food matrix can influence bacterial levels upon thawing. Collectively these data can be used to inform guidance to minimize the risk of infection from the consumption of contaminated cream-filled frozen desserts.