Russian lab worker’s unexplained death prompts quarantine amid plague speculation

Russian authorities are monitoring almost 200 people following the death of an employee at an anti-plague research institute in Siberia, although officials say testing has not confirmed that she contracted pneumonic plague.

The woman worked at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East. She died after developing severe pneumonia of an unknown cause, prompting precautionary measures in Irkutsk and the nearby town of Shelekhov.

Local reports have identified her as 28-year-old Darya Shipilova. Unconfirmed accounts claimed she may have been exposed to plague bacteria during an accident at the laboratory, but Russian authorities have not verified that version of events.

Rospotrebnadzor, Russia’s public health watchdog, said extensive testing had found no microorganisms connected to the woman’s professional activities. It also reported finding no evidence of an incident at the institute involving dangerous pathogens.

A hospital in Shelekhov was placed under quarantine and temporarily stopped admitting or discharging patients. Contacts of the researcher were placed under medical observation, with regional officials reporting that none had developed symptoms and initial tests were negative.

Testing reportedly identified common respiratory viruses in several contacts, including COVID-19, but no cases of plague. Officials described the wider epidemiological situation as stable.

Confusion increased after Alexei Tsydenov, head of neighbouring Buryatia, initially referred to a death from plague before changing his statement to say the disease was only a possibility. The Kremlin has urged the public to rely on official health information rather than speculation.

The United States said it was monitoring reports with the Centers for Disease Control and Prevention and called on Russia to share accurate information promptly.

Pneumonic plague is a severe lung infection caused by the bacterium Yersinia pestis. Unlike the more common bubonic form, it can spread between people through respiratory droplets when close contact occurs.

The disease can progress rapidly and may be fatal without early treatment, but commonly available antibiotics are effective when administered promptly. Experts have also stressed that person-to-person transmission generally requires close exposure and that swift identification and monitoring of contacts can contain isolated cases.

For now, pneumonic plague remains a suspected and unconfirmed explanation for the researcher’s death. The precautionary response reflects the seriousness of the disease, but there is currently no confirmed evidence of a wider plague outbreak.

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