Several hospitals in Siberia have been placed under quarantine following the death of a 28-year-old laboratory worker who was reportedly exposed to the bacterium that causes plague, prompting international monitoring of an incident that Russian authorities have publicly sought to downplay.
Darya Shipilova, a laboratory assistant at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East, reportedly became ill after accidentally breaking a test tube containing live biological material on 25 September. Local media said she died in the early hours of 2 October after her condition rapidly deteriorated. Nearly 200 people who had been in contact with her were reportedly placed under strict medical observation and a three-week quarantine was imposed at several hospitals in the Irkutsk region.
The circumstances of Shipilova’s illness remain disputed. According to the independent Russian outlet People of Baikal, she was working with live Yersinia pestis when the tube broke. After two days, she reportedly developed severe symptoms and was taken to hospital in Shelekhov, where doctors initially suspected coronavirus and admitted her to a specialised Covid unit. She was later placed on a ventilator before her death. The Moscow Times reported that Shipilova told medical workers she had accidentally broken a tube containing live bacteria while collecting samples.
Russian authorities have not confirmed that she died from plague. Rospotrebnadzor, the federal public health agency, described the cause of death as pneumonia of unknown or undetermined origin. On Monday, Igor Kobzev, governor of the Irkutsk region, said a special expert commission had concluded that the cause of death was “pneumonia of undetermined etiology”. He said Rospotrebnadzor testing had found that “no microorganisms linked to the young woman’s professional work were found in her biological samples”.
Kobzev also said that none of Shipilova’s contacts were showing symptoms and that testing had produced negative results. He described the situation as stable. Dmitry Peskov, the Kremlin spokesman, told reporters to “rely on Rospotrebnadzor’s official statements rather than … rumours and speculations”. Gennady Onishchenko, a former head of Rospotrebnadzor, said the infection was “most likely not the plague” and that even if plague were confirmed, there would be no spread of the disease.
Other Russian statements have been less definitive. Alexei Tsydenov, head of the neighbouring republic of Buryatia, initially said Shipilova’s death was linked to a plague infection, before his statement was amended to say she “may have died of plague”. He added that there were no plague outbreaks in Buryatia, including areas bordering Mongolia. The type of plague was not specified by Russian officials, although Russian media reports identified it as pneumonic plague, the form capable of spreading from person to person through respiratory droplets.
The response included measures that appeared to go beyond the official description of the case. Baikalsk authorities advised residents not to travel to Shelekhov because of “unofficial information about a confirmed case of plague in a person in the city of Shelekhov”. The message was deleted less than two hours later. An aluminium plant in Shelekhov made masks compulsory as a precaution, while Russian media reported that public events in Irkutsk had been cancelled. Law enforcement was also reported to have opened a criminal investigation into possible safety violations connected with Shipilova’s death.
The Irkutsk institute itself has a long history of handling dangerous pathogens. Established in 1934 by order of the Soviet Union as a “scientific operative body for plague control”, it is a state-run institution whose work is described as tightly controlled. Its activities have expanded beyond plague to diseases including cholera, brucellosis, tularemia, anthrax and arbovirus infections. Since 2001, the institute has also monitored data concerning “the amount of incidents suspicious to biological terrorism” in Siberia and the Far East.
Its structure includes anti-epidemic and plague microbiology divisions, an experimental division with biochemical and pathophysiological subdivisions, research and production facilities, animal-testing laboratories and an information-analytics division responsible for collecting and summarising national and foreign scientific literature. Professional and advanced training is also provided. Anthony Rimmington, a former Senior Research Fellow at Birmingham University, wrote in February 2025 that much of Russia’s anti-plague work remained closed to the international community.
The uncertainty has drawn attention beyond Russia. The US State Department said Washington was “aware of reports of a fatal case of suspected pneumonic plague in Irkutsk Oblast, Russia” and was monitoring the situation with the Centers for Disease Control and Prevention and other agencies. It urged Russian authorities to “share accurate information quickly and openly”.
Prof Paul Hunter of the University of East Anglia said plague infections occur regularly, with a few hundred cases globally each year. Bubonic and septicaemic plague are generally associated with flea bites and contact with infected animals, while pneumonic plague can pass between people through respiratory droplets. Laboratory-acquired infections, he said, are known to occur, “usually acquired through inhalation”.
For Filippa Lentzos, a reader in international security at King’s College London specialising in biosecurity, the central concern was not evidence of a large outbreak but the conflicting accounts surrounding Shipilova’s death. “We still need a clear account of the diagnosis, the route of exposure, what exactly happened in the lab, and whether the containment and reporting procedures worked as intended,” she said.
