A Russian laboratory technician died at a plague research center in Siberia, but pneumonic plague is usually easily controlled for a number of reasons.
The scene may sound familiar.
On Friday, a woman in Siberia died of pneumonia of "unknown cause" who may have been exposed to the plague. Russian media reported that nearly 200 people were quarantined. Officials quickly stepped in to allay concerns, but speculation and panic continued to spread online.
The 28-year-old woman is Darya Shipilova, who works at the Institute of Epidemic Prevention in the Irkutsk region of Siberia.
Unconfirmed reports suggest that she developed pneumonia-like symptoms, possibly after breaking a test tube containing Yersinia pestis, or after a field trip to the Buryatia region, which borders Mongolia. Plague is endemic among the wildlife in this area.
As of press time, Shipilova's cause of death has not been officially confirmed, and laboratory tests are reportedly still ongoing. But one thing is clear: Experts believe this case is unlikely to turn into a global epidemic. Here’s why.
Plague is caused by Yersinia pestis. Clinically, it is divided into three types: bubonic plague, pneumonic plague and septicemic plague.
Bubonic plague is the most common and is spread through the bites of infected fleas. After the bacteria enter the body, they can travel to lymph nodes and form painful bumps called "buboes" in the groin, neck and armpits. Bubonic plague rarely spreads from person to person, but the bacteria can enter the blood and cause septicemic plague; it can also enter the lungs and cause pneumonic plague.
Unlike other types, pneumonic plague can spread from person to person through tiny droplets released into the air when a sick person coughs or sneezes. Pneumonic plague is usually fatal if not treated early, with as little as 24 hours between exposure and onset of symptoms.
The Black Death, caused by bubonic plague and pneumonic plague in the 14th century, killed more than 25 million people in Europe and reduced the population by one-third to two-thirds. The newly opened trade routes at that time and the import of grain, flour and other goods by ship provided conditions for the spread of the epidemic.
However, the modern environment is much less conducive to the spread of plague.
First, pneumonic plague, caused by the bacterium Yersinia, was almost always fatal if left untreated; today, it can be cured with simple, widely available antibiotics.
“We have two treatments that are very effective against bubonic plague,” said Piero Olliaro, a professor at the University of Oxford who studies infectious diseases associated with poverty.
Bioterrorism threat?
Health agencies, including the U.S. Centers for Disease Control and Prevention (CDC), have plans in place to respond to an intentional release of plague, including contact tracing, providing guidance to hospitals, and mobilizing medical supplies.
While the risk is considered low, plague has been used as a weapon in the past.
For example, there are rumors that the corpses of infected people were thrown to the enemy in the 14th century; during World War II, the Japanese military also released infected fleas on Chinese civilians.
In 2025, Ogliaro and colleagues published the first ever randomized controlled trial of bubonic plague treatment in Madagascar. The results showed that the efficacy of oral ciprofloxacin and injectable aminoglycoside antibiotics were 91% and 92% respectively.
Furthermore, even in the few cases where the disease progressed to pneumonic plague, 85% of people improved and survived with prompt treatment.
Another reason a plague pandemic is unlikely: Unlike COVID-19, pneumonic plague cannot spread until symptoms appear, usually within 24 hours. Symptoms are severe and obvious, so subsequent cases can be quickly identified, isolated and treated before transmission occurs.
Zania Stamataki, associate professor of viral immunology at the University of Birmingham in the United Kingdom, explained: "This is not the kind of disease that will be missed. You will not get on a plane with the disease and travel around, and then new infections will appear everywhere."
She said the physical consequences of contracting the virus will become apparent quickly.
According to the World Health Organization (WHO), all contacts of the Russian patient have reportedly been identified and monitored, and no one is currently showing symptoms. This is consistent with public health advice from the US CDC: identify people considered at risk so that they can be monitored, screened, isolated and given antibiotics.
WHO spokesman Christian Lindmeier released a preliminary risk assessment on Tuesday. He told the media that the risk "is medium to low for Irkutsk, low for the Russian Federation as a whole, and very low for the WHO European Region."
In general, transmission in laboratory settings is extremely rare because strict procedures are usually in place to prevent accidental exposure. "These are very specialized laboratories with layers and layers of protection," Stamataki said.
For example, researchers wear full personal protective equipment and samples are handled only in biosafety cabinets.
These safety cabinets maintain negative pressure, with airflow from the outside in, away from the operator. "If the test tube breaks, it breaks inside the cabinet and the operator is protected," she told the BBC.
Even if the test tubes are shipped, they will be placed in a secondary sealed container. She also emphasized that technicians undergo rigorous training before working in such laboratories.
In addition, one of the main reasons why the plague spread rapidly in Europe in the 14th century was the generally poor living conditions at that time.
Garbage and food scraps litter the streets, making them ideal habitats for black rats that carry disease-carrying fleas. People lived in extremely overcrowded conditions, and merchants spent months in cramped cabins. Today, for much of the world, these conditions no longer exist.
Still, it must be said that the plague is not unique to history.
