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It’s been more than three weeks and Russian authorities still haven’t publicly answered key questions from the World Health Organization and international health experts about the death of a young lab worker at a plague research facility in Siberia.
They say she died of severe pneumonia of unknown origin — not pneumonic plague, which can spread from person to person, and had been implicated in some Russian media reports and statements by local officials. They also say there were no biosecurity incidents at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East where she worked.
But Russian officials haven’t disclosed what caused the pneumonia that killed Daria Shipilova.
Nor have they explained what prompted their extensive containment response, which reportedly included putting about 200 people who had contact with Shipilova under quarantine or observation. Russian media reported that security services escorted ambulances taking some of those contacts for medical evaluations.
I’ve reported on accidents in biological research labs in the United States for nearly two decades and wrote a book examining the history of lab accidents around the world.
That history offers three key lessons about laboratory accidents and why the unanswered questions surrounding Shipilova’s death are important.
The Takeaways
Lab workers can be infected without a recognized accident
Initial local media reports said Shipilova broke a test tube before becoming ill, but Russian authorities have since told the WHO that no biosecurity incidents occurred in the laboratory.
Studies of lab-acquired infections have documented for decades that when workers become infected, they often can’t recall having any kind of exposure incident.
As far back as the 1950s, studies found that just 16% of lab worker infections involved recognized accidents.
More recent reviews — including a key 2016 biosafety reference book chapter and a 2025 paper in The Lancet Microbe — have continued to note that the precise causes of many lab-associated infections remain unknown or aren’t documented in published reports.
Not all laboratory exposures are as obvious as an animal bite, specimen spill, or a stick with a contaminated needle. Routine lab procedures can generate infectious aerosols that workers may inhale without realizing they’ve been exposed, especially when appropriate safety equipment isn’t used.
Sometimes workers aren’t wearing protective equipment because they don’t realize they’re handling something dangerous.
Specimens believed to have been killed or inactivated may still be infectious. A specimen may also be cross-contaminated with an unexpected pathogen, or infectious organisms may linger on laboratory surfaces or clothing that weren’t decontaminated. Equipment failures can blow potentially contaminated lab air outward into “clean” hallways where passersby have no expectation of any exposure risk.
Infected workers may not realize their illness came from their lab
Initial Russian media reports, which government authorities dispute, suggested that Shipilova died from pneumonic plague. This lung infection can be lethal if not treated within 24 hours of initial symptoms, which include shortness of breath and coughing.
It remains unknown what killed Shipilova or whether her lab work played a role. Before she died with severe pneumonia, her illness seemed like a typical respiratory infection, Russian health officials told the WHO earlier this month. Tests didn’t detect any microorganisms associated with her work, Russian authorities have said.
History provides examples of scientists and other workers who failed to recognize their illness came from their lab — sometimes until it was too late.
When a tularemia researcher at the prestigious U.S. Army Medical Research Institute of Infectious Diseases — often referred to as USAMRIID — started feeling ill with a fever, chills, and headache in 2009, she never alerted the lab’s medical team because she assumed she had just caught something from her children, who also were sick.
It was only after the symptoms continued that she consulted USAMRIID’s occupational health team, which diagnosed her with tularemia pneumonia as a result of her research, according to a National Research Council review of USAMRIID safety risks. She eventually recovered.
That same year University of Chicago plague researcher Malcolm Casadaban died after becoming infected with a weakened form of the Yersinia pestis bacteria he was studying. This particular strain was not known to cause lab infections or fatalities.
For nearly two weeks, Casadaban became increasingly ill with fever, cough, and shortness of breath. There was no record of him alerting the outpatient clinic and hospital emergency department staff that his occupation involved work with plague bacteria, according to a report examining his death. The review concluded he had a health condition that made him unusually vulnerable to the weakened strain.
The public rarely learns the details of laboratory accidents
As I report in my book, “Pandora’s Gamble,” there is no universal, mandatory system for reporting lab accidents and lab-associated infections. Not in the U.S. or worldwide.
There also isn’t any comprehensive system to analyze biosafety breaches and share lessons learned so that safety can be improved. This makes it difficult to know how often accidents happen and how often workers become infected.
The 2025 systematic review of published reports during 2000 to 2024 identified 712 laboratory-acquired infections worldwide, including 276 infections and eight deaths involving research facilities. The researchers cautioned that the findings are likely an underestimate because biosafety lapses occur more frequently than are reported.
“These findings underscore the necessity of mandatory reporting and comprehensive root-cause analysis [of lab-acquired infections and accidental pathogen escapes] to strengthen biosafety oversight,” the paper said.
In the United States, safety oversight of biological research is fragmented and largely self-policing. It’s an issue that the U.S. Government Accountability Office has warned about for more than 15 years.
Only a subset of U.S. biological research labs that work with certain dangerous pathogens are subject to the Federal Select Agent Program’s mandatory biosafety regulation, inspection, and incident reporting.
During 2024, the most recent data available, the program received 224 reports of potential worker exposures that prompted medical monitoring or treatment, such as preventive antibiotics. None of the incidents resulted in documented illnesses.
But this kind of limited data can obscure serious safety breaches that the public only finds out about through pursuing internal documents through federal and state public records laws.
For example, after the critical lab waste sterilization plant serving USAMRIID at the Army’s Fort Detrick in Maryland suffered a catastrophic leak in 2018, the government assured the public that no safety threat occurred.
Only through months of digging into the government records behind the official statements was I able to report that a leaking tank had spewed thousands of gallons of unsterilized lab wastewater into an area with an open storm drain that emptied into a public waterway. While no illnesses were connected to the event, community leaders expressed concern about how they’d been kept in the dark about the extent of the incident.
USAMRIID used to publish some statistics about its lab incidents online. But the data was removed in 2022, around the time I was asking officials why more recent data hadn’t been posted. At that time, USAMRIID said the removal was part of a website update. A spokesperson for USAMRIID did not answer questions last week about why the institute hasn’t resumed posting the statistics.
Russia has its own history of concealing laboratory accidents. After dozens were killed by an accidental anthrax release from a Soviet biological weapons facility in Sverdlovsk in 1979, Soviet authorities blamed contaminated meat. It wasn’t until 1992 that the government acknowledged the outbreak was caused by military bioweapons research.
This history — and the role that Soviet-era anti-plague institutes played in the bioweapons program of that time — has heightened concerns among biodefense and public health experts about the limited information released about Shipilova’s death.
The Bottom Line
None of this history explains what happened to Shipilova and why she died on Oct. 2.
But it underscores why independent verification and public disclosure are important when a researcher working with dangerous pathogens dies under unexpected circumstances.
The U.S. State Department did not answer specific questions from Healthbeat about its assessment of the circumstances of Shipilova’s death or whether U.S. officials believe Russian authorities have provided inaccurate information.
A department spokesperson said Monday: “We encourage Russian authorities to share accurate information.”
Alison Young is Healthbeat’s senior national reporter. You can reach her at ayoung@healthbeat.org or through the messaging app Signal at alisonyoungreports.48
