"WHO is in contact with the Russian health authorities to verify the event, its circumstances, the laboratory tests underway, and their results, the rationale for contact-tracing and the health status of contacts, as well as any potential international public health implication," he said.

Rospotrebnadzor’s press service earlier said that the sanitary and epidemiological situation in the Irkutsk Region was stable, and that preventive measures and medical monitoring of people who had been in contact with the woman diagnosed with pneumonia of unknown etiology were nearing completion.

Commenting earlier on reports of an infection in the Irkutsk Region, Russian Presidential Spokesman Dmitry Peskov said people should rely on assessments by Russia’s sanitary watchdog - Rospotrebnadzor - rather than rumors and idle speculation.