Few pathogens can evoke pit-of-the-stomach dread like plague, and for good reason \u2014 the disease filled mass graves on and off for centuries.<\/p>\n
Today, however, antibiotics and ordinary medical masks can keep the bacteria from spreading, and people who receive prompt treatment have a chance of survival.<\/p>\n
The disease is in the news following the unexplained pneumonia death of a lab worker at Russia\u2019s Antiplague Research Institute\u00a0of Siberia and the Far East near Irkutsk, a Siberian city a bit larger than Baltimore.<\/p>\n
Russian authorities have said<\/a> the worker didn\u2019t have plague, but one of the country\u2019s few independent media outlets<\/a> reported that the worker had said she accidentally broke a vial containing Yersinia pestis, the bacteria that cause the disease. The country\u2019s health officials denied unconfirmed reports<\/a> of a second person with pneumonic plague.<\/p>\n Reports that the worker was only in her 20s are concerning, because people that age rarely die of pneumonia, said Dr. Heather Young, a Denver Health physician and principal investigator for the region\u2019s Emerging Special Pathogen Treatment Center.<\/p>\n Still, even if the worker did have pneumonic plague \u2014 the form of the disease that gets into the lungs and can spread from person to person \u2014 the risk to the rest of the world is extremely low, she said.<\/p>\n Currently, the Centers for Disease Control and Prevention is screening passengers entering the United States from Siberia for signs of plague. Unlike some diseases, plague can\u2019t spread before people show symptoms.<\/p>\n Plague circulates in wildlife in the Four Corners region and occasionally makes the jump to people when an infected flea bites a human or a pet, which can carry the bacteria home. Colorado has reported four human plague cases and two deaths<\/a> since 2021.<\/p>\n Hospitals in the region know to consider pneumonic plague if someone presents with sudden, severe respiratory symptoms and exposure to sick animals, Young said. Standard medical masks are sufficient to protect healthcare workers, she said.<\/p>\n A seven-day course of antibiotics can prevent infection in people exposed before they knew to wear masks. Reports from the CDC on a plague case in Arizona in 2025<\/a> and one in Wyoming in 2021<\/a> showed dozens of potential exposures in each case, but no additional infections.<\/p>\n Plague is \u201ccertainly not common, but it\u2019s something most hospitals would be equipped to handle,\u201d Young said.<\/p>\n When doctors suspect plague, they start patients on two antibiotics while waiting for test results, then step down to one when they know which will work best, Young said. Using both also increases the odds that one will be effective in the far more likely scenario that a different bacterial species is causing someone\u2019s pneumonia, she said.<\/p>\n \u201cYou want to make sure you\u2019re treating for all possible causes,\u201d she said.<\/p>\n The known facts of the case aren\u2019t particularly concerning, but the Russian government\u2019s lack of transparency with the World Health Organization<\/a> and the Soviet Union\u2019s history of bioweapons development has rattled nerves.<\/p>\n President Donald Trump has said he doesn\u2019t believe the worker\u2019s death was related to bioweapons<\/a>, while Sen. Rand Paul, a Kentucky Republican, raised concerns it was<\/a>. Neither said what evidence informed his assessment.<\/p>\n The Soviet Union kept at least two bioweapons incidents under wraps until it fell. In 1971, a ship on the Aral Sea accidentally sailed too close to an island where researchers were attempting to weaponize smallpox, causing an outbreak with three deaths in a nearby city<\/a>. Eight years later, an air leak at a facility trying to weaponize anthrax killed 68 people in the Ural Mountains.<\/p>\n Plague circulates in rodents in Siberia, as it does in the western United States, so lab workers could have been handling it for innocent reasons.<\/p>\n In the scenario where someone had possible exposure to an altered form of pneumonic plague, they would need to receive care in a biocontainment unit until researchers could tell whether it had worrisome characteristics, such as increased transmissibility or antibiotic resistance, Young said.<\/p>\n Denver Health is one of 13 hospitals in the country that have such a unit, which is separate from the rest of the hospital and is designed to prevent contaminated air from leaving a patient\u2019s room. The units are set up to care for patients with high-risk diseases, and the staff who would care for them have training to properly don the \u201cspace suit\u201d style of personal protective equipment seen during Ebola outbreaks.<\/p>\n People in Colorado don\u2019t need to lose sleep over plague, but feeling worried is understandable when information is scarce, Young said.<\/p>\n \u201cA lot of unknowns lead to concerns,\u201d she said.<\/p>\n