India, Oct. 5 -- Russian authorities said tests found no microorganisms linked to a laboratory worker's job after she died with pneumonia of unknown cause in Siberia. Nearly 200 possible contacts were placed under observation or isolation as a precaution, according to Russian and international reports.

Rospotrebnadzor,Russia's national public health and consumer protection agency identified the woman as an employee of the Irkutsk Anti-Plague Research Institute, Al Jazeera reported on October 5. The agency said wider testing did not detect microorganisms associated with her professional work.

Rospotrebnadzor also said no accident involving pathogenic microorganisms was recorded at the institute, according to Radio Free Europe Radio Liber...