// BBC WORLD NEWS — MONDO
US 'watching closely' after plague researcher dies in Russia, Rubio says
Watch: US "monitoring" suspected Siberia plague closely, says Marco Rubio
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.
The watchdog said a biological safety team had inspected the Anti-Plague Institute of Siberia and the Far East in Irkutsk and found no emergency situation there.
Kremlin spokesman Dmitry Peskov urged people not to "listen to various rumours" but "rely on Rospotrebnadzor's official statements" instead.
Russian media reported last week that nearly 200 people known to have had contact with the dead woman were under medical observation as a precaution.
Asked by a reporter for an "update on the suspected plague case in Russia", Rubio said: "It seems that there was a worker at the lab that was infected and there's concern that that, you know, could have spread, at least internally - you've seen them do quarantine of this and that nature.