A 28-year-old laboratory worker in Russia has died after developing a severe illness suspected to have been caused by an unidentified virus, prompting authorities to place at least 197 people under quarantine.
The Independent reported that the woman worked at a research facility specializing in plague, located in the city of Shelekhov near Irkutsk.
Before her death, she reportedly told doctors that she had accidentally dropped a container at work that held substances and viruses being used for research. The container was also said to have contained live disease-causing microorganisms.
She was later taken to hospital with severe pneumonia of unknown origin. Doctors placed her on a ventilator, but she died shortly afterward on Thursday, October 1, 2026.
Russia’s Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, known as Rospotrebnadzor, said emergency measures were introduced after a patient was identified with “pneumonia of unknown origin.”
The agency, however, stressed that there was no evidence of a significant outbreak in the wider Irkutsk region.
The independent regional newspaper Liudi Baikala reported that at least 197 people who were believed to have been in contact with the laboratory worker or people who had been in contact with her were placed in quarantine. More than 100 of them were being monitored in hospitals.
Authorities also introduced strict quarantine measures at several locations, including Shelekhov District Hospital, a nearby maternity facility and an aluminium processing plant.
Irkutsk Governor Igor Kobzev urged residents to remain calm. In a message posted on Telegram, he said a regional anti-epidemic commission had met to assess the situation.
Although Kobzev did not mention the worker’s death in the message, he said that all identified contacts were showing no symptoms of illness and that tests carried out so far had not detected an infection.
Russian law enforcement authorities have also launched an investigation into possible violations of health and workplace safety regulations that may have contributed to the woman’s death.
Because the facility where the woman worked conducts research involving pathogens that can cause serious diseases, speculation has emerged that she could have contracted pneumonic plague. However, this has not been confirmed.
Pneumonic plague can spread from person to person through respiratory droplets released by an infected individual.
The World Health Organization says the disease can be fatal if left untreated. However, early detection, treatment with appropriate antibiotics and measures to prevent transmission can significantly improve the chances of controlling the infection.