In Pictures: Arizona Death Renews Questions Around a Historic Killer

Once a medieval killer, plague continues to resurface in rare cases across the world, including the United States. (ILLUSTRATION: News18)

Pneumonic plague is the most severe form and can spread from person to person through respiratory droplets. (ILLUSTRATION: News18)

Visualizing the three deadly forms of plague—bubonic, septicemic and pneumonic—and how each spreads through different transmission routes. (ILLUSTRATION: News18)

Despite medical advances, infections like the plague can still spread through flea bites or contact with infected animals. (ILLUSTRATION: News18)

Globally, 1,000–2,000 cases of plague are still reported each year to the WHO, with most concentrated in certain regions. (ILLUSTRATION: News18)

Understanding how plague is transmitted is key to preventing future outbreaks—even in the developed world. (ILLUSTRATION: News18)