Russia is facing a wave of online misinformation following the death of a laboratory worker at an institute in Irkutsk that studies plague and other infectious diseases.

Dozens of people were placed under observation after the worker died of severe pneumonia, prompting widespread speculation across social media platforms.

Posts ranged from comparisons with the COVID-19 pandemic to unsubstantiated claims about a laboratory accident involving the plague pathogen, Yersinia pestis.

One post on X, written in Russian, claimed a lab technician broke a flask containing the plague virus and died within days, alleging she had infected several hundred people in the process.

That post, which included a photo of the alleged laboratory worker, accumulated over 320,000 views before fact-checkers began examining its core assertions.

Russia’s public health authority, Rospotrebnadzor, stated that two separate commissions investigating biosafety procedures at the Irkutsk Antiplague Research Institute of Siberia and Far East found “no evidence of an accident involving pathogenic microorganisms.”

The Russian news agency TASS, citing Rospotrebnadzor, also reported that tests conducted on the deceased employee detected no microorganisms linked to her professional activity at the institute.

Some social media users attempted to counter the broken flask claim by pointing to standard safety protocols in high-containment laboratories, where glassware use is frequently restricted or banned entirely.

A separate misleading claim alleged that the World Health Organization updated its plague fact sheet on the same day the Irkutsk laboratory worker was hospitalized, implying a deliberate connection between the two events.

The WHO did update its plague fact sheet on September 29, the same day the worker was hospitalized in Shelekhov with severe respiratory symptoms, but no evidence links the two events.

The update was part of a broader WHO publication cycle on infectious disease, accompanying a news release covering global surveillance data on cholera, meningitis and plague spanning 2019 to 2025.

The previous version of the WHO plague fact sheet, accessible as an archived page, was dated July 7, 2022, suggesting the September update was part of a routine revision schedule rather than an emergency response.

A social media account that promoted the WHO timing claim changed its name in October to one suggesting it was reporting live from Irkutsk, though its profile indicated it was created in May and is based in Australia.

Such accounts frequently emerge during fast-moving news events, presenting themselves as local or specialist sources while circulating unverified information to large audiences.

A third category of misinformation involved old footage being recycled and falsely presented as evidence of plague spreading to other parts of Russia.

One video posted on X carried a caption reading, “The plague marches across Russia. God has heard our prayers!” and claimed the disease had reached regions beyond Irkutsk.

A reverse image search revealed the video was first posted on August 31, showing the Russian republic of Kabardino-Balkaria, a tourist destination approximately 6,000 kilometers from Irkutsk.

The Russian news agency TASS reported on August 31 that plague had been detected in local squirrels in that area and that the region had been closed to tourists, confirming the footage predates the Irkutsk incident entirely.

The old video had been viewed more than 1.7 million times on Instagram and was also circulated on Telegram, amplifying a false narrative that plague was spreading across multiple Russian regions simultaneously.

The situation in Irkutsk remains under investigation, with health authorities implementing precautionary measures and ongoing testing, but no confirmed plague outbreak has been reported anywhere in Russia.