The death of a worker at an anti-plague laboratory in Russia has prompted officials to put at least one hospital facility under quarantine and nearly 200 people reportedly under medical observation as of Monday.
The female staffer at the Irkutsk Anti-Plague Institute of Siberia and the Far East died from a “pneumonia of undetermined” origin last week, according to the regional governor, Igor Kobsev.
He said no “microorganisms linked to the employee’s professional activities were detected” in her body, and that there had been “no new cases” of illness among other employees of the lab.
“The sanitary-epidemiological situation” in the area “is currently stable,” Kobsev said.
On Friday, Maksim Modin, mayor of the Shelekhov municipal district near the border with Mongolia, said that the inpatient facility where the worker is said to have been treated had been closed for quarantine. Russian media cited officials saying that nearly 200 people who had been in contact with the woman had been placed under precautionary medical observation.
Russian media outlets have named the woman and identified her as being 28 years old. These details have not been confirmed by officials.
Meanwhile, there have been calls internationally for more information and greater transparency from Moscow.
“Many details have not been confirmed,” a State Department spokesman said. “We encourage Russian authorities to share accurate information quickly and openly.” The spokesman said there had been “reports of a fatal case of suspected pneumonic plague” in Irkutsk oblast.
Secretary of State Marco Rubio said Monday that despite there being “very limited travel between the U.S. and Russia,” if “something like that gets out, it could quickly spread.” So the United States government is “watching and monitoring it closely,” he added. “I don’t think it’s cause for alarm, but it is cause for focus and a cause just to keep an eye on it.”
The World Health Organization said in a statement that it was aware of reports that a lab worker had died of “severe pneumonia” but that “no cause of death has been officially confirmed.”
Asked by NBC News in Moscow whether the Kremlin was following these events, President Vladimir Putin’s spokesman Dmitry Peskov said Rospotrebnadzor, Russia’s consumer welfare service, was handling the investigation.
“It is their official statements that should be relied upon— rather than paying heed to various rumors, speculations, and the like,” he said. “Rospotrebnadzor employs highly qualified professionals in this field, so let us heed their official statements.”
Dr. Ashish Jha, the White House’s former Covid response coordinator, told NBC News that “much more” information and transparency were needed from Moscow. He said that if this is an isolated case of pneumonic plague and no one else dies, “it will probably end there.”
But “it’s actually very hard” for pneumonic plague to spread from person to person, Jha said. “We may see a few more people get infected, but the chances that this becomes a larger outbreak, let alone a global pandemic, is exceedingly low,” he said.
“If there were weapons programs, biological weapons programs in these labs, that would be much more concerning to me,” he said. “We need to understand that now.”
The pneumonic plague is caused by the same bacteria as the bubonic plague and can spread from person to person through airborne respiratory droplets, typically from sneezing or coughing. Medical experts say cases require rapid treatment with powerful antibiotics to prevent fatalities.
From 2019 to 2025, 10 countries reported more than 3,800 suspected human plague cases to the WHO, the agency said last week. Six of the countries ended up having confirmed cases, most of them in the Democratic Republic of the Congo and Madagascar, with 423 deaths.