Cause of Russian Lab Worker’s Death Remains Unclear

A 28-year-old employee of Russia’s Irkutsk Anti-Plague Research Institute, Darya Shipilova, died after developing severe pneumonia of unknown cause, and Russian authorities say tests found no evidence that her illness was linked to a pathogen associated with her work. The cause of her death and whether there was any laboratory exposure remain unresolved; no plague outbreak has been confirmed. Russian officials said about 200 people who may have had contact with Shipilova were placed under observation. The health watchdog later reported that 60 had been released. Officials also said no laboratory accident had been detected and that testing had not identified a pathogen connected to her work. The accounts do not establish that all those monitored had the same type of contact with Shipilova. The World Health Organization has requested further information from Russian authorities about the cause of the pneumonia, the pathogen that prompted public-health measures and reports of another employee with pneumonia. The Kremlin has denied reports of a second death.