Rumours swirl after Russian research lab worker dies
The World Health Organization has asked Russia for more information on the death of a worker at a Siberian plague research laboratory.
Health officials in Russia are still investigating the circumstances, but early reports show that anyone who had contact with the deceased researcher tested negative for pneumonic plague. The cause of the worker’s illness remains unclear, leading to wide speculation in the media.
Below is a brief look at what pneumonic plague is, how it spreads, and how it can be treated, as experts weigh in on what is at stake.
Pneumonic plague is the most virulent form of plague, shown here as microscopic clusters of Yersinia pestis.
What is pneumonic plague?
Pneumonic plague is the most serious form of plague, attacking the lungs and producing cough, chest pain and sometimes bloody sputum. The disease can evolve from the bubonic or septicemic types and is rarer but more deadly. Roughly 1,000 to 3,000 plague cases occur globally each year across Africa, Asia, the Americas and the United States; most are bubonic and a minority are pneumonic.
“Plague itself has not disappeared; the bacterium Yersinia pestis persists in animal reservoirs across many parts of the world.” says Prof Piero Olliaro, University of Oxford. “Sporadic human cases therefore continue to occur, but established surveillance, infection‑control measures and effective antibiotic treatment are key to limiting their impact.”
How does it spread?
The bacteria that cause plague live in small mammals and their fleas. Humans can contract the disease when bitten by an infected flea or by handling an infected animal. In addition, pneumonic plague can be transmitted from person to person via airborne droplets from coughing, but this requires close contact.
Historical scholarship suggests pneumonic plague was likely the dominant form behind the Black Death that decimated Europe in the 14th century.
Dr Zania Stamataki, Associate Professor of Viral Immunology at the University of Birmingham, stresses the importance of laboratory research: “Plague remains endemic in rodent populations across Africa, Asia and the Americas, and human cases occur every year. Diagnostics, vaccine development and surveillance for antibiotic resistance all require laboratories that hold and study the live organism. This work is vital to prepare against outbreaks.”
Can it be treated?
The World Health Organization reports that pneumonic plague has a very short incubation period—sometimes just 24 hours. If not diagnosed and treated quickly, it is nearly always fatal. However, the disease responds well to antibiotics when treatment begins early.
Dr Malick Gibani, Clinical Associate Professor in Bacterial Vaccinology at Imperial College London, explains: “Pneumonic plague is a severe manifestation of plague disease. Its mortality rate can approach 100% if left untreated, but with antibiotics—especially if started early—survival is possible. Therefore high‑risk exposures may be offered post‑exposure prophylaxis or quarantine.”
In the Russian case, it remains uncertain whether the deceased worker contracted pneumonic plague; earlier tests found no microorganisms linked to the patient‑fulfilling lab work. U.S. officials and the UK Health and Safety Authority have described the risk to the general public as very low, while the U.S. Centers for Disease Control noted no indications of a broader threat to the United States.
