After a spike of human cases of the plague in 2015, a year the disease inflicted 16 people across portions of the western United States, the number of occurrences this year have dropped. Four cases of human plague in 2016 were reported in New Mexico, one of several western states where the infectious bacterial disease is commonly found, according to the Centers for Disease Control and Prevention. Between 1900 and 2015, there have been 1,036