The World Health Organization said Saturday that Russia's state health regulator has confirmed the death of a laboratory worker at a plague research institute in Siberia but reported that no case of plague has been registered.
The employee worked at the Irkutsk Antiplague Research Institute of Siberia and the Far East. She was hospitalized on September 29 with severe pneumonia and died on October 2 under circumstances not initially disclosed. Pneumonic plague was suspected following possible occupational exposure in a laboratory setting.
Russia's National Focal Point for the Inter-Agency Standing Committee informed the WHO that tests conducted on the deceased worker and people who had been in contact with her were negative for the dangerous pathogens tested for, according to the WHO statement. Her contacts showed no symptoms, and no further linked cases of severe pneumonia had been found.
The WHO said it still does not know what caused the pneumonia that killed the worker. The organization said it is awaiting a confirmed diagnosis from Russian authorities.
Russian health authorities told the WHO that no biosecurity incident had occurred in the laboratory, contrary to some reports circulated online. They also stated that control measures had been adopted and that laboratory analysis of people in contact with the worker had revealed no presence of high-risk pathogens.
The incident prompted Russian authorities to place approximately 200 people in quarantine. The case drew attention on social media and prompted monitoring by international health agencies, including the U.S. Centers for Disease Control and Prevention, which said it was aware of and closely monitoring the situation.
The WHO became aware of the incident on October 2 through media reports about the research institute in Irkutsk.