Nearly 200 monitored after Russian plague lab worker dies of unexplained pneumonia

Nearly 200 people have been placed under medical observation in Russia’s Irkutsk region after an employee of an anti-plague research institute died following a severe respiratory illness, according to local reports.

Russian public health watchdog Rospotrebnadzor said the employee had been diagnosed with “pneumonia of unknown etiology.” The agency said expanded testing found no microorganisms connected to her laboratory work and that the sanitary and epidemiological situation in Irkutsk, Shelekhov and the surrounding region remained stable. No further infections have been reported.

Local media reports had identified the illness as suspected pneumonic plague and said the woman became sick after returning from Buryatia, where a plague outbreak had reportedly occurred near the Mongolian border. Some reports also alleged that she had broken a test tube containing the plague pathogen. Russian officials have denied that testing established a work-related plague infection.

Two hospitals and a children’s clinic were placed under quarantine, according to official Russian figures cited by Deutsche Welle, while institute employees were reportedly isolated at their workplace.

The United States is monitoring the reports and assessing options, Axios and other outlets reported, citing a Trump administration official. Axios also reported that President Donald Trump said the United States was willing to help Russia.

Pneumonic plague is a lung infection caused by the bacterium *Yersinia pestis*. The World Health Organization describes it as the most virulent form of plague; it can spread through respiratory particles and is fatal without prompt treatment.