Irkutsk lab worker dies of plague as nearly 200 placed under observation

Nearly 200 people have been placed under medical observation in Siberia after a laboratory worker at a disease research institute died from plague.

The victim, identified in Russian reports as 28-year-old Daria Sh., worked at the anti-plague institute in Irkutsk. She was admitted on Tuesday to a district hospital in the nearby town of Shelekhov with symptoms resembling severe pneumonia. Put on a ventilator as her condition deteriorated rapidly, she died on Thursday.

According to Russian reports, she told hospital staff before she died that she had accidentally broken a test tube containing live bacteria while gathering samples for testing. Investigators have opened a criminal inquiry into possible safety violations causing death.

Containment measures and quarantines

Health authorities responded by locking down the Shelekhov district hospital, placing its medical staff and patients under quarantine. Across the Irkutsk region, officials have isolated at least 197 people who may have crossed paths with her. More than 100 of those contacts are being held in hospital wards under round-the-clock observation.

Planned public gatherings in Irkutsk have been cancelled. Russia's chief sanitary doctor, Anna Popova, travelled to the region to direct the emergency response alongside local officials.

Irkutsk Governor Igor Kobzev said that emergency screening had found no spread of the infection. "All identified contact persons have been placed under medical observation. As of today, the contacts show no signs of illness, and their laboratory test results are negative," Kobzev said in a statement on Telegram.

Unclear route of infection

Regional officials initially referred to the incident only as a "particularly dangerous infection", but Alexei Tsydenov, head of the neighbouring republic of Buryatia, later confirmed the cause of death as plague.

Tsydenov sought to dispel speculation that the technician had contracted the disease on fieldwork in his territory, which borders Mongolia and contains known natural plague reservoirs. Citing findings from consumer health regulator Rospotrebnadzor, he said she had not travelled to Buryatia and insisted there were no active outbreaks across the regional border.

While the test tube mishap was reported as the primary explanation she gave doctors, conflicting versions have circulated. Other reports suggested she had recently returned from fieldwork, while another claimed an accidental laboratory rat bite was being reviewed.

Health authorities have not yet confirmed whether the woman died from pneumonic plague, which can spread through respiratory droplets from person to person, or bubonic plague, which is typically transmitted through bites from infected fleas or contact with tainted fluid. The speed of her respiratory decline led treating doctors to treat the case as suspected pneumonic plague.

Natural reservoirs of plague persist among rodent populations in parts of Central Asia, Siberia, and Mongolia. Human infections in Russia remain rare; the last confirmed domestic case was recorded in 2016, when a 10-year-old boy fell ill in the Altai mountains after skinning an infected marmot.