The plague rarely affects humans, though the US sees about 7 cases a year. Here’s why

AP Health Writer

Colorado health officials have confirmed a human case of the plague. The rare bacterial infection is infamously known for killing tens of millions in 14th century Europe. Today, it’s easily treated with antibiotics. The Centers for Disease Control and Prevention estimates seven human cases of plague per year in the U.S. The plague spreads naturally among rodents and is transmitted through the bites of infected fleas. It can be cured when treated early with antibiotics, but the key is to get to a doctor fast.