The U.S. Centers for Disease Control and Prevention is monitoring reports of a suspected fatal case of pneumonic plague in Russia’s Irkutsk region, while saying the circumstances remain unconfirmed and there is no indication of a broader threat to the United States.
In its statement on X on Tuesday, the agency said: “CDC is aware of and closely monitoring reports of a suspected case of pneumonic plague in the Irkutsk region of Russia that resulted in a death. We are working across the U.S. government to assess developments as additional information becomes available.”
European and World Health Organization officials are also monitoring the laboratory worker’s death in Siberia, as authorities seek to establish what caused the illness. The CDC said: “At this time, there is no indication of a broader threat to the United States, but CDC and our interagency partners are prepared and will continue to monitor the situation closely.”
The woman worked at the Irkutsk Anti-Plague Research Institute and died after developing pneumonia. Russian authorities have described the illness as pneumonia of unknown cause. At a United Nations briefing Tuesday, WHO spokesperson Christian Lindmeier said no cause of death had been officially confirmed, and that the organization remained in contact with Russian authorities under the International Health Regulations.
Based on the information available, the WHO’s initial assessment placed the risk at moderate to low for the Irkutsk region, low for Russia as a whole and very low for the WHO European Region. Lindmeier said Russian authorities had reported that testing of the woman’s contacts had not detected dangerous infectious pathogens.
In a separate update Tuesday, the European Centre for Disease Prevention and Control said there were no reports of secondary cases and no evidence of sustained human-to-human transmission that would lead to further spread. The agency expressly based that assessment on limited information. It said it was continuing to monitor the situation and was in contact with WHO Europe.
Russian health watchdog Rospotrebnadzor said medical observation had ended for 60 percent of the woman’s contacts, according to an update reported by Interfax. The agency reported two COVID-19 infections and two rhinovirus infections among contacts, with no other infectious agents detected. It also said inspections had found no accident involving pathogenic microorganisms at the institute and that testing of the deceased had not identified microorganisms associated with her professional work.
The CDC’s statement emphasized that effective treatment is available, while underscoring the importance of acting quickly when plague is suspected. It said: “While the circumstances of this reported case remain unconfirmed, plague is a serious bacterial disease that is treatable with antibiotics, particularly when recognized and treated early.”
Plague is caused by the bacterium Yersinia pestis. According to the CDC, people usually become infected through the bite of an infected rodent flea or by handling an infected animal. Pneumonic plague affects the lungs and can develop when an infection spreads there from elsewhere in the body, or when a person inhales infectious droplets from an infected person or animal. The agency said: “Pneumonic plague can spread person-to-person through respiratory droplets during close contact, which is why rapid identification and treatment of infected individuals, and monitoring of potentially exposed individuals, are important public health measures.”
The European agency similarly advised that patients with suspected or confirmed pneumonic plague be isolated and receive appropriate treatment, with close contacts identified and monitored promptly. It said transmission generally requires close, prolonged contact with someone already showing symptoms. The CDC identifies rapidly developing pneumonia, fever, weakness, shortness of breath, chest pain and cough among the symptoms, and stresses that prompt treatment is critical to preventing severe complications or death.
