A worker at a plague research institute in Siberia has died, and nearly 200 of her contacts are under medical observation. Russian authorities deny a link to the bacterial infection. The US is monitoring the situation.

A laboratory worker in Irkutsk died after developing severe pneumonia amid reports of possible plague exposure at an anti-plague institute. The episode has drawn scrutiny because nearly 200 contacts are under observation, though officials have not confirmed plague.

A suspected pneumonic plague case in Russia has left nearly 200 people under medical observation after a 27-year-old laboratory worker died, prompting concerns over the rare and potentially fatal infection.