Russia Says 200 Contacts Are in Quarantine After a Plague-Lab Worker's Unexplained Death in Siberia

The World Health Organization says it does not yet have the full picture of the death of a Russian laboratory worker who had been studying plague, and it cannot carry out a full risk assessment. The employee, a 28-year-old woman, died last week from pneumonia of unknown origin at a lab in Siberia, roughly 2,500 miles from Moscow, according to reporting by NPR's Russia correspondent Charles Maynes.

Russia's consumer health watchdog investigated and concluded that no pathogens in her body were connected to her work with infectious disease. Moscow has denied there are any cases of plague in the area. But local media have raised concerns about the spread of pneumonic plague, which NPR has not independently confirmed. Authorities say 200 people who had contact with the woman are in quarantine.

At a press conference Wednesday, WHO Director-General Tedros Adhanom Ghebreyesus said the Russian assurances were, at the very least, incomplete. "We don't yet have the full picture of this event and we're not able to conduct a full risk assessment," he said.

Plague is a bacterial disease that takes several forms depending on which part of the body the bacteria invade. A flea bite typically causes bubonic plague, marked by swollen, painful lymph nodes called buboes. When the bacteria reach the lungs, the result is pneumonic plague, which often has no telltale sign, according to the U.S. Centers for Disease Control and Prevention.

That version is far more dangerous. "It transmits pretty easily between people because it spreads through droplets, almost like COVID spreads," said Adelaide Miarinjara, a medical entomologist at Emory University. She added that people can die more quickly from pneumonic plague because it progresses faster. "The key here is early diagnosis. If people aren't expecting it or don't seek treatment, they can die." Treatment is antibiotics, often given by IV infusion.

Madagascar's 2017 outbreak shows how quickly it can move. A person from a rural area brought the disease to the coastal city of Toamasina, which had not seen a plague case in nearly a century, and the infection spread on public transportation. The country recorded more than 2,400 suspected cases, including nearly 1,900 of pneumonic plague, and one study estimated about 25 percent of people with confirmed cases died.

Quarantining contacts is a time-tested response. The practice of isolating the sick goes back at least 3,000 years, and the word itself comes from the Black Death, when the city-state of Dubrovnik forced visitors to wait 40 days on an island before coming ashore. The Russian lab worker's cause of death remains officially unexplained, and the quarantine of her contacts continues.