Kazakhstan's Ministry of Health stated it is monitoring the situation in Russia's Irkutsk region, clarifying that the illness is not plague but "pneumonia of unknown etiology." A 27-year-old resident of the Irkutsk region, an employee of the Irkutsk Anti-Plague Institute, died on October 2.

Reports suggest the woman may have broken a vial containing the disease's pathogen in a laboratory, or she returned from a trip to Buryatia, an area with a plague outbreak near the Mongolian border. Hospitalized with pneumonia symptoms and placed on a ventilator, she died days later. The hospital was quarantined, and 189 out of 197 identified contacts were hospitalized.