US 'watching closely' after plague researcher dies in Russia, Rubio says

US'watching closely' after plague researcher dies in Russia, Rubio says To play this video you need to enable JavaScript in your browser. The US says it is closely monitoring the case of a Russian lab technician who died at a plague research centre in Siberia. Secretary of State Marco Rubio said there was concern the incident could have led to the spread of pneumonic plague, but that there was no cause for alarm. Announcing the cause of death as pneumonia of undetermined etiology, Irkutsk's governor said that no micro-organisms linked to the woman's work had been found in her biological samples. Unconfirmed reports had suggested the woman fell ill either after breaking a test tube containing the pathogen or following a field trip to a region where plague is found naturally among wild rodents. No other cases of staff from the plague institute seeking medical attention since her death had been reported, Irkutsk governor Igor Kobzev said, quoting Russia's consumer and health watchdog, Rospotrebnadzor.