Did a Russian lab worker die from pneumonic plague? What we know — and don't know

An unnerving story has emerged from southeastern Russia involving the death of 28-year-old woman from pneumonia and fears that she may have been exposed to a form of plague at the lab where she worked.

Yes, plague — specifically, pneumonic plague.

Few details are confirmed. Russian authorities say there is currently no evidence that the illness was connected to any of the pathogens she worked with at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East.

But the governor of a neighbouring region fuelled speculation over the weekend when he posted on Telegram suggesting the woman had died of plague, later altering his comment to include "maybe."

People have been quarantined at the hospital where she died last week; many others who came in contact with her were put under medical supervision, according to Anna Popova, Russia's public health agency.

There are, however, questions about Russian authorities' transparency, along with general shock at the thought of someone dying from an illness associated with the Middle Ages — and that many don't realize still exists.

Here's what we know and what we don't know about the situation in the Siberian city of Irkutsk, the lab worker who died and what Russian and other global officials are saying about the case.

What happened?

Russian state-run news agency TASS reported that the employee was "diagnosed with pneumonia of unknown etiology."

Local media reports have identified her as laboratory technician Darya Shipilova, saying she died on Friday.

The lab, which was established under the former Soviet Union in 1934, carries out scientific research on plague control, vaccine development and epidemic prevention, as well as work on other dangerous infectious diseases like cholera, brucellosis and anthrax.

CBC News has not independently confirmed Shipilova's identity or details about her work.

A view of the Medical Assistance and Rescue Centre, an infectious diseases hospital, in the town of Shelekhov in the Irkutsk region of Russia, on Oct. 5. (Stringer/Reuters)

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Russian-language reports say that Shipilova went to a hospital in Shelekhov, about 20 kilometres southwest of Irkutsk, days before her death.

Per Ria Novosti, another state-run outlet, Irkutsk Region Governor Igor Kobzev announced on Friday that a resident had been diagnosed with a "a particularly dangerous infection" of an undetermined nature.

"Importantly, over the past few days, no new cases of staff from the Anti-Plague Institute seeking medical attention have been identified," Kobzev said.

What is pneumonic plague?

Plague, which came to be known as the Black Death when it ravaged Europe in the 1300s, is an infectious disease caused by a bacterium known as Yersinia pestis, or Y. pestis. It is carried by small mammals and generally spread by the fleas that feed off them.

Those fleas can transmit Y. pestis to humans and other large mammals.

There are three forms of plague: bubonic, septicemic and pneumonic.

Bubonic plague, the most common form, causes buboes — painful, inflammed lymph nodes near the site of a flea bite. Symptoms usually come on after three to seven days, and can include fever, chills, headache and extreme exhaustion.

Septicemic plague happens when bubonic plague infections aren't treated and spread to the bloodstream and other parts of the body. It can cause vomiting, diarrhea, multiple organ failures and septic shock.

Pneumonic plague is when Y. pestis infects the lungs, making it much more of a risk because it can then be transmitted between people through airborne droplets.

Symptoms — including high fever, cough, coughing up blood and difficulty breathing — can occur within one to three days of inhalation. It can be fatal if left untreated.

A bubonic plague smear, prepared from a lymph removed from an adenopathic lymph node, or bubo, of a plague patient, showing the presence of the Yersinia pestis bacteria that causes the plague. (U.S. Centers for Disease Control and Prevention/Getty Images)

How deadly is it?

Plague is easily treated with antibiotics, which did not exist during the Black Death, Dr. Malick Gibani, a clinical associate professor at Imperial College London, told CBC News.

But people do still die from it, he says, though that's generally restricted to certain geographic areas, often due to conditions that attract rodents, or the fact that they are remote.

Between 2019 and 2025, the World Health Organization (WHO) recorded 3,847 suspected cases and 423 deaths in 10 countries. Most of those infections occurred in the Democratic Republic of Congo and Madagascar.

In 2017, a pneumonic plague outbreak in the latter country affected more than 2,400 people and killed 209 people.

But Gibani notes that plague infections can occur in other parts of the world like parts of Russia, as well as in South America and and parts of the western U.S.

Siberia was the location of the first known prehistoric human outbreak of plague.

Do I need to be worried?

While there are still many unanswered questions, this possible outbreak is nothing like the COVID-19 pandemic because plague is "a much different pathogen," said Angela Rasmussen, a virologist at the University of Saskatchewan.

Even before they become sick, infected people are "constantly shedding" the virus that causes COVID-19, she said, which is how it spread so far.

"You're not going to be walking around feeling fine, shedding Yersinia pestis everywhere for everybody else to breathe in," she said.

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In fact, you should be more concerned about coming into contact with an infected rodent than getting an infection potentially from a lab in Siberia, she says.

Even though it's not been officially confirmed that Shipilova died of pneumonic plague, Gibani says a rapid response is key to controlling the spread in any situation like this.

He says that can include contact tracing and offering antibiotics to those who may have been identified as being at risk of exposure.

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How is the rest of the world reacting?

Russian officials have sought to quell fears about a possible outbreak.

But some countries, such as Kazakhstan, aren't taking chances and are raising alerts or implementing quarantine at border crossings. Tajikistan, Uzbekistan and Kyrgyzstan have implemented similar measures even though they don't share borders with Russia.

The WHO is in contact Russian health authorities and has offered support if needed, a spokesperson said in a statement to CBC News.

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U.S. President Donald Trump also said his administration would also offer assistance.

"Anybody that has that kind of a problem, we're always willing to help," Trump told reporters as he left the White House for a trip to Nebraska, calling the possible outbreak a "big problem for Russia."

Health Canada told CBC it is also monitoring the situation, though it sees no risk to Canada at this time. According to the agency, the last recorded human case of plague in this country was in 1939.

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