Ukrainian Foreign Minister Andrii Sybiha said Russia's handling of a suspected pneumonic plague case fit what he described as Moscow's history of concealing information about dangerous incidents, citing the 1979 anthrax outbreak, the Chornobyl disaster, and the COVID-19 pandemic, according to his post on X on 8 October.

A 28-year-old worker at the Irkutsk Anti-Plague Research Institute, Daria Shipilova, died at Shelekhov District Hospital on 2 October. The hospital was placed under quarantine, and nearly 200 people who had contact with her were put under medical observation.

Sybiha has called on Russia to disclose all the facts surrounding the case, provide transparent epidemiological data, and cooperate with international mechanisms.

"Russia has a long record of concealing the truth: the 1979 anthrax leak in Sverdlovsk, the 1986 Chornobyl disaster, and the true scale of COVID-19 in 2020–2022," he said.

Plague is caused by the bacterium Yersinia pestis, which is usually found in small mammals and their fleas. Bubonic plague, the most common form, is caused by the bite of an infected flea. Pneumonic plague is the most virulent form: left untreated, it can be fatal within 18 to 24 hours of onset, though common antibiotics can cure it if given early.

But each time, the consequences were devastating.

Sybiha warns of the risks of secrecy

Sybiha added that there is compelling evidence that Russia has used chemical weapons in Ukraine and has threatened to use nuclear weapons in its genocidal war. His remarks came amid rumors that the plague could have originated in a biological laboratory developing weapons.

"The world must not wait for another catastrophe before asking questions," he said.

Russia must disclose all the circumstances surrounding the case, provide transparent epidemiological data, and cooperate with international mechanisms because “when dangerous pathogens are involved, secrecy is a threat to everyone,” Sybiha added.

WHO seeks more information from Russia

The World Health Organization (WHO) says it still lacks the data it needs for a full risk assessment, while Russia has told the organization that no cases of plague have recently been reported in Irkutsk Oblast.

WHO Director-General Tedros Adhanom Ghebreyesus says that the organization has asked Russia for "further information on the laboratory tests conducted on the individual who died and the contacts," more details on what prompted the public health measures, and the health status of the contacts. The organization also seeks verification of media reports of a second employee with pneumonia of undetermined cause.

Based on "unofficial information," the public health risk to the general population appears to be low, WHO spokesperson Christian Lindmeier says, according to Forbes.

US officials say they know little about what is happening in Russia

On 6 October, US Secretary of State Marco Rubio said information з приводу вирогідної хвороби from Russia was "still quite limited."

The next day at the White House, a reporter asked US President Donald Trump whether the plague in Russia was a bioweapon, according to CNN.

"Well, we don't think so. We're going to find out soon enough, but we don't think so," he said.

The reporter also asked whether Trump was “getting the same vibe right now from Russia that you got from China at the start of COVID.”

"Well, China didn't say much, and Russia's not saying much either, but they do say they have it very much under control,"  Trump answered.