The writer is a health scientist and author of ‘The Irrational Ape: Why We Fall for Disinformation, Conspiracy Theory and Propaganda’
The death of Russian plague researcher Daria Shipilova has ignited a firestorm of speculation over the circumstances of her death and a chorus of concern over the potential for an epidemic. While details of the incident remain scant and contradictory, history offers us some important context.
Fear is an understandable initial response to a pathogen so odious it has acquired the moniker “plague”. The Yersinia pestis bacterium was responsible for two of the deadliest pandemics in human history; the plague of Justinian (541-549 AD) and the Black Death. By the end of its terrible reign in the mid-1300s, the Black Death had killed somewhere between 30 and 60 per cent of Europe’s population.
Infections can take a variety of forms, depending on how the disease affects the body. Most common is bubonic plague, defined by swollen, blackened lymph nodes that gave the middle-age pestilence its name. Septicaemic plague results from bacteria entering the bloodstream, while inhalation of bacteria leads to pneumonic plague. While severity and prognosis vary markedly, the same agent is responsible for all forms.
Today that once relentless killer is now relatively easily treated with antibiotics, its deadly legacy often considered a relic of antiquity. But Y pestis never went away — it remains endemic in parts of the world. Between 2019 and 2025, the WHO recorded 3,847 suspected cases and 423 deaths worldwide. While most stemmed from the Democratic Republic of Congo and Madagascar, there were also cases in the US and China. Russia itself last reported wild cases in 2018. As plague remains an active threat in many regions, Y pestis is still actively researched worldwide. Plague has been endemic in Siberia for millennia — the Irkutsk Institute where Shipilova worked was established there in 1934.
As with all research, there are risks. Pathogen research is conducted at an array of universities and hospitals worldwide, and laboratory-acquired infections (LAIs) and accidental pathogen escape from laboratory settings (APELs) are periodic occurrences. Historical incidents of lab infections have involved everything from poliovirus to Ebola. A review in the Lancet Microbe journal identified 309 LAIs and 16 APELs worldwide between 2000 and 2021. Of the eight LAI fatalities during the period, plague exposure accounted for two. Crucially, however, even with highly pathogenic agents, neither LAIs nor APELs typically result in onward chains of transmission due to multiple levels of containment and risk mitigation.
Even so, Russia’s long history of being less than transparent about medical hazards renders it harder than it should be to clarify matters. While Moscow is obliged to report such incidents within 24 hours, the incident came to the attention of WHO only after conflicting stories were being shared on local and social media. One version insists Shipilova was exposed after breaking a test tube, concealing the accident and fatally delaying vital life-saving measures. Another telling asserts she was exposed during a field trip. Russian health authorities have downplayed the plague entirely, stating Shipilova died of “pneumonia of unknown etiology”, finding “no micro-organisms linked to her professional activity”.
Inevitably, the incident has conjured up the spectre of bioweapons. Chinese and European accounts from the 1300s detail attempts by warring factions to weaponise the plague. Most infamous was the siege of Caffa in 1346, where Mongol attackers catapulted afflicted corpses into the city. More recently, the Soviet Union and imperial Japan experimented with weaponised plague during the second world war. But, evocative as this is, there is no evidence Shipilova’s death stemmed from anything so nefarious.
Whatever the cause of her tragic death, quarantining staff members and close contacts seems a reasonable caution rather than inherently ominous. Pneumonic plague is always concerning as it can spread from person to person by infected droplets. Untreated patients, however, get severely ill extremely quickly, drastically limiting transmission potential. While lab accidents happen, the likelihood of onward transmission remains vanishingly small. The chances of it triggering an epidemic are virtually zero, especially given infection is now readily treatable.
While we are still unclear as to what precisely transpired in Russia, this incident is a stark reminder that transparency is vital to mitigate the harms of such events. We can never afford to be complacent about our vulnerability to the microscopic.