London School of Hygiene & Tropical Medicine

On Monday 5 October 2026, it was reported that a 28-year-old female laboratory worker at a Russian institute researching plague, who may have been exposed to pneumonic plague, has died.

The incident, which took place at the Irkutsk Anti-Plague Research Institute of Siberia, reportedly prompted authorities to place nearly 200 people under observation at a local hospital. 

Russia’s national public health agency, Rospotrebnadzor, said that the technician had contracted “pneumonia of unknown aetiology [cause].” The agency has since conducted extensive testing and anti-epidemic measures.

Brendan Wren, Professor of Microbial Pathogenesis at the London School of Hygiene & Tropical Medicine (LSHTM), said: "Plague is a serious infectious disease caused by the bacterium Yersinia pestis. Historically, the disease was transmitted from infected fleas to humans, although human-to-human spread can occur through respiratory droplets in cases of pneumonic plague. It can cause a rapidly progressing septicaemia that may become life-threatening within 48 hours if left untreated.

"Reports from Russia about this case suggest that the infection resulted from an accidental inoculation following a broken test tube, highlighting the importance of strict biosafety procedures when handling dangerous pathogens. 

"While this incident has attracted global attention, laboratory-acquired infections with Yersinia pestis are rare because human-to-human transmission of plague is relatively uncommon compared with respiratory viruses such as SARS-CoV-2 or COVID-19. In this case, I would not describe the accidental laboratory-based transmission to a single individual as an outbreak, and it seems unlikely that it will lead to a wider epidemic. 

"Although pneumonic plague is the most severe form of the disease, as it can spread via the respiratory route, it remains treatable with antibiotics when diagnosed promptly. Globally, around 2,000 cases are reported each year, mostly in areas where the disease remains endemic, including regions of the western United States, public health authorities within these regions have extensive experience in managing suspected exposures.  

"In order to prevent further transmission in cases such as this, the monitoring and isolation of laboratory staff and other key contacts is a sensible and precautionary measure as it helps ensure any potential onward transmission is detected and treated quickly." 

This is a rapid reaction to a breaking news story.