Researcher in Russia Dies from Plague; 189 People Under Observation

A researcher at a Russian anti-plague institute has died from what has been identified as a case of plague, according to reports. Local media indicate that as many as 189 people have been placed under medical observation in Irkutsk, a region in eastern Siberia, due to potential exposure to the disease. The World Health Organization (WHO) stated it is aware of reports regarding the death of a laboratory worker in Irkutsk oblast from severe pneumonia on Friday and has offered support to Russia. The cause of death has not been officially confirmed, and laboratory testing is currently underway, the agency informed CNBC in a statement. The WHO noted, "All of the patient's contacts have reportedly been identified and are being monitored for illness, and none to date have shown symptoms of illness." Plague is a rare but potentially fatal bacterial infection that remains endemic in parts of the world, including western regions of the U.S., but can be treated with antibiotics if identified quickly. It is caused by the bacterium Yersinia pestis, usually found in small mammals and their fleas, and it comes in various forms. The recent case in Russia appears to be pneumonic plague, which infects the lungs and can develop from another form of plague or by inhaling infectious particles. Unlike bubonic plague, which typically does not spread person to person, pneumonic plague poses a greater concern for disease control. The Yersinia pestis bacterium exists in natural animal reservoirs, particularly among rodents, making eradication challenging. The WHO reports that animal plague exists on every continent except Oceania, although human cases do not occur everywhere those reservoirs exist. Brendan Wren, a professor at the London School of Hygiene & Tropical Medicine, commented, "Potentially this lab-acquired case of pneumonic plague could be transmitted by the respiratory route. Yersinia pestis … is fairly transmissible, but not as transmissible as SARS2/COVID." Russia's public health watchdog, Rospotrebnadzor, reported that the employee at the anti-plague research institute had been diagnosed with "pneumonia of unknown aetiology." The situation in Irkutsk and Shelekhov is described as "stable," with measures implemented in response to the case. Alexei Tsydenov, head of the nearby Republic of Buryatia, stated on social media that the individual died from an unspecified form of plague but denied any travel to Buryatia. CNBC has not independently verified these reports, and the Russian Ministry of Health did not immediately respond to requests for comment. Wren noted that there are still around 2,000 cases of plague annually, which are treatable with standard antibiotics, but warned of emerging multi-antibiotic resistant strains that could limit treatment options. He added that a lab worker may have been working with Yersinia pestis samples to develop improved vaccines for regions where the plague is endemic, and if the bacterium were weaponized, a vaccine for military personnel could be necessary. Rospotrebnadzor stated that no microorganisms associated with the diseased patient's professional activities have been detected. The agency did not immediately respond to a request for further information from CNBC. The WHO indicated that based on unofficial information, the public health risk to the general population appears to be low, and the risk assessment will be updated as more information becomes available.