The World Health Organization said Saturday it still does not know what caused the death of a 28-year-old laboratory worker at a Russian plague research institute in Irkutsk, but confirmed no plague case has been registered in the region.
Russian health authorities told the WHO that tests on the worker, identified by Russian media as Darya Shipilova, and her contacts were negative for dangerous pathogens, including plague, according to the U.N. agency. The worker died on Oct. 2 after developing severe pneumonia of unknown origin, prompting the quarantine of about 200 people. Her contacts showed no symptoms, and no further linked cases of severe pneumonia were found, the WHO said.
Russia’s health watchdog, Rospotrebnadzor, reported that the worker was appropriately vaccinated and that no microorganisms linked to her work were detected in her body. Post-mortem tests did not confirm plague, and authorities said no biosecurity breaches occurred at the Irkutsk Antiplague Research Institute of Siberia and the Far East. Russia also denied media reports of a second employee with pneumonia of undetermined cause, which WHO had previously cited from tabloid outlets.
The WHO called for continued investigation, stating that “a key uncertainty remains the absence of a confirmed diagnosis in the deceased laboratory worker.” It added that more than 5,500 tests conducted by Russian officials found no evidence of high-risk pathogens. The U.S. has urged Russia for transparency, while the WHO continues to monitor the situation .
