What is the pneumonic plague?

The death of a young Russian lab worker from severe pneumonia has renewed global attention on pneumonic plague. While Russian authorities informed the World Health Organization that no plague cases were recorded in the Siberia region, the circumstances of the death and subsequent precautions have triggered international scrutiny. The WHO is currently seeking more information from Russia regarding the incident. Although plague caused historic pandemics, modern human cases are rare and typically treatable with antibiotics.