Yersiniosis in Poland in 2018-2020.

AIM

The aim of the study was to assess the epidemiological situation of yersiniosis in Poland in 2018-2020 and compare it to previous years.

MATERIAL AND METHODS

To assess the epidemiological situation of yersiniosis in Poland, data from individual case reports prepared by Sanitary Epidemiological Stations as part of routine epidemiological surveillance were used. Incidence, number of cases and data on hospitalizations by voivodship included in the bulletins "Infectious Diseases and Poisons in Poland" for 2015-2020 were also used.

RESULTS

In 2018-2020, a total number of 542 cases of yersiniosis were registered, including 456 intestinal and 86 extraintestinal forms. The incidence in 2018 was 0.53/100,000 in 2019 0.59/100,000 and in 2020 0.29/100,000. The number of cases in 2020 compared to 2019 decreased by 52%, and compared to 2018 by 45.8%. The percentage of hospitalizations in each year was at a similar level of 65.5% in 2018, 62.4% in 2019, and 60% in 2020. The highest incidence was noted in the 0-4 age group at 44.7% of cases in 2018, 42.9% in 2019 and 55.6% in 2020, respectively (all cases of the intestinal form). The predominant species was Y. enterocolitica in both intestinal and extraintestinal forms. The most common serotype was serotype O:3, which was identified in 34 isolates in 2018, 43 isolates in 2019 and 9 isolates in 2020.

SUMMARY AND CONCLUSIONS

Since 2009, Poland has had a decreasing trend in the incidence of yersiniosis. In 2020, both Poland and Europe saw a sharp decline in the number of cases compared to previous years. This is a result of the occurrence of the COVID-19 pandemic in March 2020, during which many measures were introduced to limit the spread of the SARS-CoV-2 virus, which may also have affected the number of other infections. Although the numbers of cases and incidence of yersiniosis among children under the age of 5 are the highest compared to other age groups, the highest number of hospitalizations was reported in the 10-19 age group, which most likely reflects the decreasing number of laboratory tests ordered on an outpatient basis with age and the significant underreporting of cases in this and older age groups.