Does a Russian lab worker's death carry pandemic risk? Experts say it's unlikely, with one caveat

This article originally appeared on PolitiFact.

It sounded familiar: Pneumonia reported near a lab studying infectious pathogens in a country where the government is known to conceal unfavorable information.

Conflicting reports and unanswered questions about a potential pneumonic plague death in Russia on Oct. 2 returned memories of COVID-19's early days.

READ MORE: What we know so far about a Russian lab worker's death and pneumonic plague

A laboratory worker at an anti-plague research lab in Siberia died of an illness, and a local official initially reported the woman had died "possibly from the plague." The earliest reports sounded like the death followed an accidental lab exposure to pneumonic plague, the World Health Organization reported. Dozens of people had been quarantined or isolated.

The WHO confirmed the woman's death followed her hospitalization with "severe pneumonia," but the exact pathogen that caused her illness has not been announced or independently verified.

Adding to the confusion: Russian authorities reported no recent case of plague in Irkutsk Oblast, an administrative region in east-central Russia, where all this was said to have happened.

Despite some of the situation's parallels to the coronavirus news of late 2019 and early 2020, virology and health security experts told PolitiFact's Well Informed they don't see signals this is a precursor to another pandemic crisis.

The caveat, however, could be significant: Russian authorities' actions didn't align with their public statements.

Although the government's official statement was that the lab worker had pneumonia of undetermined origin, Russia responded by putting 200 contacts under observation, quarantining a hospital and flying its top disease control leader to Irkutsk.

"That is not how you respond to garden-variety pneumonia — and it isn't really how you'd respond to ordinary plague either, which has been curable with cheap antibiotics for decades," Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, said.

Even without confirmation of the pathogen, however, the shape of spread is the most important factor to watch. "Pandemic potential shows up as a growing chain of human-to-human transmission, and that is not what we're seeing," he said.

Adalja said no cluster of severe illness had developed among nearly 200 people who The Moscow Times reported were placed under medical observation.

Hayley Anne Severance, deputy vice president for the Nuclear Threat Initiative's global biological policy and programs, said she needed more information before providing a global health risk assessment.

"I am still in 'wait-and-see' mode," Severance said. "We need to know more about laboratory test findings, the treatments provided and her reaction to them, and any other potential exposure factors. We do not have confirmation of the causative agent, or if there even is an infectious agent involved, so we are flying in the dark here."

Experts are watching Russian authorities, local media for reports of more cases

Currently, about 10 days after the researcher's death, there have been no secondary cases confirmed in connection with the lab worker's death.

"If this were a fast-spreading cluster, the window in which we'd expect to see it has basically passed," Adalja told Well Informed on Oct. 8.

WATCH: Understanding pneumonic plague after Russian lab worker's death

Other concerns would include expanding quarantine measures and Russian authorities refusing outside investigators or blocking a WHO team, Adalja said.

Local media reports could also offer clues, Severance said.

"I would be concerned if I begin to see reports from independent news outlets in Russia that there are unreported cases or deaths ongoing in the region that are not being acknowledged or confirmed by official Russian sources," she said.

Standard pneumonic plague isn't a significant pandemic threat

Pneumonic plague occurs when someone inhales respiratory droplets that contain the bacteria Yersinia pestis — or when the bacteria causing bubonic or septicemic plague spreads to the lungs.

It can be treated with antibiotics. Without prompt treatment, pneumonic plague has "a nearly 100% case-fatality rate," according to the U.S. Centers for Disease Control and Prevention.

It is the only plague that can spread person to person, usually with prolonged contact.

Measures such as masking could decrease disease spread. Pneumonic plague's incubation period is short — about one to four days — so it's less likely infected people would spread disease unknowingly, Severance said.

"In past pneumonic plague outbreaks, on average, each infected person spread to between one and two others," and that dropped quickly with isolation measures, Severance said.

Experts worry about information obstruction

WHO officials said the illness that caused a lab worker's death in Russia presents a "very low" risk to people outside of Russia, based on available information. But more answers are needed.

"A trained worker inside a plague research institute died of something still unexplained, and we're relying on the word of a government with a documented history of concealment on biosecurity," Adalja said.

Ian Jones, a virology professor at the University of Reading in the United Kingdom, said it was "almost unbelievable" that scientists hadn't identified the cause of the lab worker's pneumonia given modern testing capabilities.

WHO Director-General Tedros Adhanom Ghebreyesus urged timely and transparent information sharing.