(CNN) -- A squirrel in Colorado has tested positive for the bubonic plague. The squirrel tested positive on July 11 in the town of Morrison, marking the first case of plague in the county this year, according to a news release from the Jefferson County Public Health (JCPH) department. On July 7, Chinese authorities confirmed a case of the bubonic plague in inner Mongolia. There are approximately 1,000 to 2,000 cases every year, but that is likely a modest figure as there are a number of unreported cases, according to the WHO. If left untreated, the bubonic plague can turn into the pneumonic plague, which can cause pneumonia after bacteria spreads to the lungs.