Two outbreaks of Yersinia enterocolitica (YE) serotype O: 3 have been reported to the Finnish National Institute for Health and Welfare in the past week.
The epidemic is suspected in the hospital districts of Itä-Savo and Helsinki and Uusimaa. In addition, one suspicion of an epidemic has been reported from the Pirkanmaa Hospital District, and the associated patient populations have not been serotyped.
The suspected time of the epidemic is between 2 and 17 February 2022 and is estimated to be less than 100 exposed.
More cases in Eastern Savonia than before
In February 2022, five cases of YE from the Itä-Savo Hospital District were reported to the Infectious Diseases Register, while in 2019–2021 no cases were reported from the Hospital District at the corresponding time.
A total of 39 YE cases were reported in Finland as a whole in February 2022, which is less than in February 2021, when there were 55 cases. Serotype data of YE strains reported to the Communicable Diseases Register are not currently available to THL.
Local health professionals play a key role in detecting and combating epidemics caused by yersinia. THL does not monitor for the presence of yersinia infections over time, and yersinia strains isolated from patients are not routinely submitted to the THL reference laboratory for typing.
THL is asking hospital districts and municipalities to monitor the local situation and report RYMY suspected food-borne epidemics.
In addition, THL requests clinical laboratories to submit patient populations related to reported epidemics to the RYMY system for typing into the THL, and to include Y. enterocolitica serotype and biotype information, if available, in the communicable disease notification and strain referral.