The World Health Organization (WHO) has asked the Russian government for more information about the death of an employee at a Siberian plague research unit, including details about the laboratory tests conducted on her, the WHO Director-General told a media briefing on Thursday.

The WHO has also asked Russia for more details about the public health measures it has imposed, the health status of the woman’s contacts, and whether a second employee has been infected with “pneumonia of undetermined cause”, said Dr Tedros Adhanom Ghebreyesus.

This follows reports on Monday of the death of a 27-year-old female employee at the Irkutsk Anti-plague Research Institute of Siberia and the Far East – possibly of pneumonic plague.

The employee was hospitalised at Shelekhov Hospital on 29 September with symptoms of pneumonia, placed on a ventilator and died a few days later, according to media reports.

Tedros said that the WHO had sent queries to Russia on Saturday, and received a report on Wednesday that “no case of plague had recently been reported in the Irkutsk Oblast” where the research unit is, and that they had “placed about 200 [of the woman’s] contacts in quarantine”.