Russian health authorities have told the World Health Organization that no cases of plague have been recorded in the Siberian city of Irkutsk, following the death of a laboratory worker at a research institute specialising in the disease.
The development was disclosed by the WHO on Tuesday after the UN health agency sought clarification from Moscow over the circumstances surrounding the worker’s death.
According to WHO spokesperson Christian Lindmeier, Russian authorities formally responded to the request and said there was no evidence of plague infection in the city.
"No case of this dangerous disease has been recorded in the city of Irkutsk, Russian Federation," the Russian authorities said in their response, which Lindmeier read during a press briefing in Geneva.
The response came after Russian authorities had previously informed the WHO that they were investigating whether pneumonic plague may have been responsible for the laboratory worker’s death.
The worker was employed at a plague research institute in Irkutsk and died last week, prompting international attention because of the nature of her workplace and the potential risks associated with pneumonic plague.
Under international health regulations, Moscow is required to respond to requests from the WHO concerning potentially significant public health threats within 24 hours.
Contacts identified, tests negative
The Russian authorities also informed the WHO that they had identified people who had been in contact with the deceased laboratory worker.
According to the information provided to the UN health agency, tests conducted on those contacts for dangerous infectious pathogens were negative.
However, it remained unclear whether the laboratory worker herself had been tested for plague before her death and whether Russian authorities had definitively ruled out the disease as the cause of death.
Reuters reported that it could not immediately establish whether such testing had been carried out.
The Russian diplomatic mission to the UN in Geneva also did not immediately respond to a request for comment.
The uncertainty is significant because pneumonic plague is a severe form of plague that affects the lungs and can spread through respiratory droplets in certain circumstances. The disease is caused by the bacterium Yersinia pestis.
WHO says public risk remains low
Despite the circumstances surrounding the laboratory worker’s death, the WHO has previously assessed the risk to the wider population as low.
The agency’s position indicates that, based on the information available, there was no evidence at the time to suggest widespread transmission of plague among residents of Irkutsk.
The latest communication from Russian authorities provides further reassurance that no confirmed cases have been identified in the city.
Nevertheless, the circumstances surrounding the laboratory worker’s death remain under investigation, particularly whether plague played any role in her illness.
The WHO’s request to Russia reflects the international health system’s procedures for monitoring and responding to potential outbreaks of diseases that could pose a threat beyond national borders.
For now, Russian authorities say there are no recorded plague cases in Irkutsk, while the WHO continues to monitor the situation based on information supplied by the country.