Yersiniosis in Poland in 2014.

Objective: The aim of the study is to present the epidemiological situation of yersiniosis in Poland in 2014 and compare it with the situation in the previous years.

Material And Methods: The evaluation was based on analysis of data from the annual bulletins “Infectious diseases and poisoning in Poland” for the period 2009-2014 (MP Czarkowski et al., National Institute of Hygiene and GIS – Chief Sanitary Inspectorate), interviews of individual yersiniosis cases, sent by the sanitary-epidemiological stations from the whole country and the data on deaths from the Department of Demographic Studies of the Central Statistical Office.

Results: In 2014 in Poland 244 cases of yersiniosis were recorded (0.63/100 000). Among them 241 infections were caused by Y. enterocolitica and 3 by Y. pseudotuberculosis. There were 215 cases of intestinal yersiniosis and 29 of extraintestinal. Hospitalization required 59.8% of patients. There were no deaths reported which cause was infection with Yersinia. Intestinal yersiniosis was manifested the mostly by symptoms as follow: diarrhea (88%, including 8% with blood in stool), fever (66%), abdominal pain (49%) and vomiting (22%). The most of the cases (131 - approx. 61%) of intestinal yersiniosis occurred among children in the age group 0-4 years . Number of extra intestinal Yersinia infections (20 cases) was higher than in 2013. The most frequent symptom of those cases was osteoarticular pain, which was observed in 79% of patients. As in 2013 most cases of intestinal yersiniosis were reported from the Mazowieckie voivodeship (104 cases). Serological type of Yersinia was determined only in 58 (24%) cases. This percentage was the lowest since the start of registration of yersiniosis in the country in the year 2006. The identified serotypes were O3 (88%) O8 (6.9%) and O9 (5.2%). In 2014, 4 cases of infection with “American” serotype O8 were identify. One family outbreak caused by Yersinia spp occurred in 2014.

Conclusions: A significant decrease of serologically identified cases of yersinia observed in 2014. could be explained by the test for Yersinia not being reimbursed by routine health care insurance. Reporting cases of extraintestinal yersiniosis from only few voivodeships suggests that the real number of infections remains underreported. In 2014 significantly higher number of cases of Yersinia infection occurred during the second and third quarter of the year. Seasonality of yersiniosis in 2014 differs from seasonality in 2013. However, it was similar to the seasonality observed in previous years (2009-2012).