India, Oct. 5 -- A suspected pneumonic plague case in Russia's Irkutsk region has sparked health concerns after a 28-year-old anti-plague institute worker died following severe pneumonia, with nearly 200 people placed under medical observation. However, health officials have not confirmed that plague was the cause of the death. The World Health Organisation says plague is caused by the bacterium Yersinia pestis. Though it can be serious, early detection and treatment with antibiotics can help. Here is everything you need to know.

What Is Pneumonic Plague?

Pneumonic plague is the lung-based form of plague caused by the bacterium Yersinia pestis. WHO describes it as the most virulent form of plague. It can develop when plague bacteria spr...