WHO Reports No Confirmed Plague Cases Following Death of Russian Lab Worker

The World Health Organization (WHO) stated that it does not know the cause of the pneumonia that led to the death of a laboratory worker at a Russian plague research institute, and no cases of plague have been registered. Russia's state health regulator informed the WHO that tests on the worker and individuals who had contact with her returned negative for the pathogens tested, according to a statement from the UN health agency on October 7, 2026. The contacts of the deceased worker have not shown symptoms, and no additional cases of severe pneumonia have been identified. The WHO noted, "Based on the information provided… WHO has not identified evidence of ongoing transmission associated with this event. A key uncertainty remains the absence of a confirmed diagnosis in the deceased laboratory worker." The worker fell ill and died under undisclosed circumstances on October 2, prompting authorities to quarantine about 200 individuals and raising public health concerns on social media. Russian media identified her as Darya Shipilova, a 28-year-old laboratory technician at the Irkutsk Antiplague Research Institute in Siberia. Pneumonic plague, caused by the bacterium Yersinia pestis, was initially suspected. The governor of neighboring Buryatia mentioned that the woman had “died, maybe of the plague.” However, Russia's health watchdog Rospotrebnadzor reported that she was diagnosed with “pneumonia of unknown aetiology.” Russian authorities stated that the worker was appropriately vaccinated and that no microorganisms linked to her work were found in her body, with post-mortem tests not detecting plague. On October 6, a local official reported that 60 percent of those in quarantine had been released. WHO chief Tedros Adhanom Ghebreyesus requested Russia to address media reports of a second employee with pneumonia of undetermined cause, which Russia dismissed as “false information.” The United States has also called for transparency from Russia. Global health officials remain vigilant regarding pneumonia cases of unknown origin since the COVID-19 pandemic, which began with a cluster of severe respiratory illnesses in China. The cause of individual pneumonia cases is often undetermined.