Rubio asks Russia for details on Siberian plague lab worker death

US Secretary of State Marco Rubio has urged Russia to share more information about the death of a 28-year-old lab worker at a plague research centre in Siberia, saying the US is watching the situation closely. Russian officials say they are investigating the cause of death, but all contacts of the victim have tested negative for pneumonic plague. The WHO confirmed Russia has identified and is monitoring all individuals who came into contact with the worker. The incident has sparked speculation about how the worker became ill, though Russian authorities have dismissed unconfirmed reports. The plague bacterium, which caused the Black Death, remains a threat in the region, but experts say antibiotics can treat the pneumonic form.