Russian Lab Worker Dies of Mysterious Illness; Nearly 200 Under Observation Amid Suspected Plague Exposure

October 5, 2026

Moscow/Irkutsk: A laboratory worker at an anti-plague research institute in Russia’s Siberian region of Irkutsk has died after developing severe pneumonia, while nearly 200 people have reportedly been placed under medical observation amid concerns over a possible pneumonic plague infection.

The case has triggered precautionary measures and international attention, although Russian health authorities have not confirmed that the woman died of plague or that there was a virus leak from the laboratory. Russia’s public-health watchdog has described her condition as pneumonia of unknown cause.

Lab Worker Dies After Severe Pneumonia

The deceased has been identified by local and international reports as 28-year-old Daria Shipilova, a laboratory technician at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East.

Reports said Shipilova was admitted to a hospital on September 29 after developing severe pneumonia and was later placed on a ventilator. She died between October 1 and 2.

Some reports have claimed that she accidentally broke a test tube containing live plague bacteria while working at the research facility on September 25. However, this account has not been independently verified, and Russian authorities have not established that her illness was caused by exposure to plague bacteria.

Nearly 200 People Placed Under Medical Observation

Authorities have reportedly placed around 197 people under medical observation after tracing individuals who may have come into contact with the deceased. Several medical facilities in the region have also introduced precautionary quarantine measures.

According to reports, people under observation have not shown symptoms and tests conducted so far have returned negative results. Russian authorities have said the epidemiological situation in the Irkutsk region remains stable.

Precautionary measures have also been introduced at some facilities in the area, including mask requirements at an aluminium plant in Shelekhov.

Russia Yet to Confirm Pneumonic Plague

The main concern is whether the laboratory worker was infected with pneumonic plague, a serious form of plague caused by Yersinia pestis. Unlike bubonic plague, pneumonic plague affects the lungs and can spread between people through respiratory droplets.

However, Russia’s public-health watchdog, Rospotrebnadzor, has said the woman was diagnosed with pneumonia of unknown aetiology and reported that no microorganisms associated with her professional activities were detected.

The uncertainty surrounding the case has drawn international attention. A US State Department official said Washington was aware of reports of a suspected fatal pneumonic plague case in Irkutsk and was monitoring the situation with the CDC and other agencies.

As of October 5, there is no officially confirmed plague outbreak in Russia. Authorities are continuing to investigate the cause of the laboratory worker’s death and monitoring those who may have been exposed.