A worker at Russia's plague research institute in the remote Siberian region of Irkutsk has died of suspected pneumonic plague, according to a US official.
"We are aware of reports of a suspected case of pneumonic plague in Irkutsk Oblast, Russia. We are closely monitoring the situation with the CDC [Centers for Disease Control and Prevention] and other interagency partners," a US State Department official told Al Jazeera.
"Many details remain unconfirmed. We encourage Russian authorities to share accurate information promptly and publicly," the official said.
The governor of the Buryatia region, Alexei Tsydenov, said in a post on his Telegram channel on October 3 that a woman in the neighbouring Irkutsk region had "died, possibly of plague".
Russia's official TASS news agency on Sunday cited a statement from the consumer watchdog Rospotrebnadzor saying that an employee of the Irkutsk Research Institute for Plague Control of Siberia and the Far East had been diagnosed with "pneumonia of unknown origin".
The watchdog also said it had expanded testing of the patient's samples and found no microorganisms related to her occupational work.
Pneumonic plague is caused by the bacterium Yersinia pestis, which typically lives in small mammals and their fleas. According to the World Health Organization, plague is highly infectious and can be fatal if not treated early.
Local media named the deceased worker as Darya Shipilova, 28, a laboratory technician.
Media reports said authorities in the Irkutsk region of Siberia had placed nearly 200 people under medical observation.
