The aim: The aim of the study is to assess the epidemiological situation of salmonellosis in 2015-2016 in Poland, compared to the previous years.
Material and methods: The assessment of the epidemiological situation was performed on the basis of data from bulletins “Infectious diseases and poisonings in Poland”, information from the laboratories of Sanitaryepidemiological Stations and data from epidemiological investigations of outbreaks which were provided by Sanitary-epidemiological Stations through the Register of Epidemic Outbreaks (ROE) to the Department of Epidemiology of Infectious Diseases and Surveillance as well as data from the Department of Demographic Studies of the Central Statistical Office. Cases were classified according to the implemented case definitions.
Results: In 2015, a total of 8 650 cases salmonellosis were reported. Among them 8 418 were cases of intestinal salmonellosis and 232 of extraintestinal one. Total incidence was 22.5/100 000. 8235 (95,2%) cases met the criteria for confirmed case and 415 cases were classified as probable. In comparison to 2014, the percentage of hospitalized persons increased slightly and remained at a high level of 71.8%. The increase of salmonellosis cases, as in previous years, occurred in the summer months. In 2015 he highest incidence was recorded in the Małopolskie and Mazowieckie voivodeships, and the lowest in the Lubuskie. Children 0-4 were most often affected, especially at the age of 2 and 3 years old. Number of reported foodborne outbreaks caused by Salmonella was 190. Among them 154 were caused by Salmonella Enteritidis. This serotype, as in previous years was the most frequently isolated. Out of the 433 571 tested people who were working with food, 0.2% were infected with Salmonella. In 2016, the total number of reported cases of salmonellosis was 10,027 cases, which was close to 16% increase in cases compared to the previous year and over 19% increase compared to 2014. There were registered 9,701 cases of intestinal and 326 extraintestinal infections. 9,713 cases were classified as confirmed, accounting for 96.9% of all and 314 cases were classified as probable ones. The percentage of hospitalizations in 2016 remained at a similar level as in previous years (71.1%). The peak of incidence as in the previous year was in July. The highest numbers of cases were recorded in the Małopolskie and Mazowieckie voivodeships, which accounted for 23% of all reported cases. As in previous years, most often affected were children at the age 0-4. In 2016 number of reported outbreaks of foodborne infections caused by Salmonella sp. was 240. In 85% of them S. Enteritidis serotype was isolated, which as in previous years was the serotype most frequently isolated in outbreaks and sporadic diseases. Among 443 419 people working with food who were tested for Salmonella 0,2% were positive, as in the previous year.
Conclusions: The increase in the incidence of salmonellosis in 2015-2016 in Poland may be related to the outbreak detected in 2016, covering more than a dozen EU countries, associated with eggs originating in Poland. Observed in the last several years high percentage of hospitalizations due to salmonellosis is a consequence of rare laboratory testing for salmonellosis by GPs of patients with gastroenteritis. It also results in the low sensitivity of salmonella surveillance in Poland.
Keywords: salmonellosis; intestinal salmonellosis; extraintestinal salmonellosis; epidemiology; Poland; 2015; 2016.