A plague research employee in Russia died from an unknown cause. Here's what we know

There are more questions than answers regarding the death of a plague research lab employee last week in Siberia. Here's what we do and don't know. Transcript LEILA FADEL, HOST: Russian authorities are telling people to stay calm after a worker at an infectious disease institute in Siberia died. The cause of the illness that killed her is unknown, and that death has led people to speculate about the outbreak of the plague or another very infectious disease. Joining us to talk about where things stand is NPR's Russia correspondent Charles Maynes in Moscow. Good morning, Charles.CHARLES MAYNES, BYLINE: Morning, Leila.FADEL: So what do we know about what happened?MAYNES: Well, so one thing that's never been disputed - last Tuesday, a 28-year-old female lab worker at an anti-plague research institute in Siberia's Irkutsk region fell ill and died two days later. The cause of her death is where things get murky. The head of Russia's consumer health watchdog, a body called Rospotrebnadzor, was dispatched immediately to the area - that's some 2,500 miles from Moscow - and quickly declared this young woman had died from pneumonia of an unknown origin.A follow-on investigation by the agency ...