Published : 05 Oct 2026, 12:04 PM
Updated : 05 Oct 2026, 12:04 PM
Nearly 200 people have reportedly been placed under medical observation in Russia's Siberian region of Irkutsk after the death of a worker at an anti-plague research institute prompted reports of a suspected pneumonic plague infection.
The United States is monitoring the case, while Russia's public health watchdog has not confirmed a plague infection and says the epidemiological situation in the region remains stable.
Rospotrebnadzor, Russia's public health watchdog, said the employee of the Irkutsk Anti-Plague Research Institute of Siberia and the Far East had been diagnosed with "pneumonia of unknown aetiology".
Expanded testing of samples from the patient found no microorganisms associated with her professional activities, according to a Rospotrebnadzor statement carried by Russia's TASS news agency.
CNBC, citing local media reports, said 189 people had been placed under medical observation following the woman's illness.
Local media identified the woman as 28-year-old laboratory technician Darya Shipilova.
Alexei Tsydenov, head of the neighbouring Russian republic of Buryatia, said on Oct 3 that the woman had "died, maybe of the plague", according to Al Jazeera.
He also said there were no plague outbreaks in Buryatia.
Russian authorities have maintained that the situation in the region is stable.
Rospotrebnadzor said the sanitary and epidemiological situation in the Irkutsk region and the cities of Irkutsk and Shelekhov was stable. It also said no accidents involving work with pathogenic microorganisms had been recorded at the institute.
Irkutsk Governor Igor Kobzev earlier said identified contacts were under medical observation and showed no signs of illness, with laboratory tests returning negative results at the time.
The case has nevertheless drawn attention in the United States.
"We are aware of reports of a fatal case of suspected pneumonic plague in Irkutsk Oblast, Russia," a US State Department official told Al Jazeera.
The official said Washington was monitoring the situation with the Centers for Disease Control and Prevention and other government agencies, while cautioning that many details remained unconfirmed.
The State Department also urged Russian authorities to provide accurate information "quickly and openly".
The White House is also monitoring reports about the case and Russia's quarantine measures, CNBC reported, citing Axios.
Pneumonic plague is the most virulent form of plague, an infectious disease caused by the bacterium Yersinia pestis.
Unlike the more common bubonic form, pneumonic plague can spread between people through respiratory particles. It can be rapidly fatal if left untreated, but antibiotics are effective when treatment begins early, according to the World Health Organization.
The WHO says laboratory testing is required to confirm plague by identifying Yersinia pestis in samples such as blood or sputum.
Russian authorities have so far reported no such confirmation in the Irkutsk case.
