The WHO is asking Russian authorities for more information about a possible plague case in a high-security laboratory worker: here's what we know so far about the potential threat

The World Health Organization has formally requested information from Russian authorities regarding the death of a high-security laboratory worker in Irkutsk, Siberia, which is being investigated as a potential case of pneumonic plague. The incident occurred on October 2, involving an employee who worked with dangerous pathogens.

While international bodies and reports treat the incident as a potential pneumonic plague threat, Russian authorities have officially attributed the death to a "pneumonia of unknown etiology." Furthermore, Russian officials have denied implementing any specific contagion prevention measures in response to the event.