spawns/iStock (NEW YORK) — A child in Idaho contracted the plague last year, leaving many wondering how the plague exists in the 21st century. The disease dates back to the Middle Ages, when it killed millions in a Europe, before the age of antibiotics. At the time, they did not realize the plague was carried by the fleas who lived on rats. Although the idea of the plague sounds dire, another “black death” is not coming. The plague, in spite of its lethal reputation, is not uncommon in the U.S. and it is usually no longer a death sentence. According to the Center for Disease Control and Prevention, the plague was first introduced in the U.S. in 1900 by rat-infested steamships. It is most common in the western U.S. What is the plague? The plague is caused by a bacteria called Yersinia pestis, which is transmitted by fleas. Infected fleas spread the infection to animals, commonly mice, squirrels, prairie dogs and even cats and dogs. Humans get the plague through direct contact with...