Several hospitals in Irkutsk imposed three-week quarantines, according to the outlet People of Baikal, in a text cited by Meduza on October 4.

The measure followed a case of “pneumonia of unknown cause” in an employee of the Irkutsk Anti-Plague Institute, according to Meduza. About 200 people at the hospital where the worker was taken were placed under observation, according to The Telegraph.