(PUEBLO, Colo.) — The Pueblo Department of Public Health and Environment (PDPHE) and the Colorado Department of Public Health and Environment (CDPHE) are investigating a human case of plague after initial test results came back positive in Pueblo. According to PDPHE, the plague bacterium, Yersinia pestis, is transmitted by fleas and cycles naturally among wild rodents. Plague can infect humans and their pets, and can be contracted from the bites of infected fleas, by touching or skinning infected animals, or by inhaling droplets from the cough of an infected person or animal. Typical symptoms of plague include sudden fever and chills, severe headache, muscle aches, nausea, vomiting and a feeling of illness. A common symptom of plague is also swollen lymph nodes with pain.  PDPHE provided some steps you can take to protect yourself and your pets: Eliminate places that rodents can hide and breed around your home, garage, shed or recreation area. Remove brush, rock piles, trash, and piles of lumber. Avoid contact with dead animals. If you must handle sick or dead animals, follow these guidelines: Apply insect repellant to protect yourself from fleas Use a long-handled shovel to place it in a garbage bag Place the bag in an outdoor garbage can Use insect repellent that contains 20%-30% DEET to prevent flea bites. Treat pants, socks, shoe tops, arms, and legs. Do not let pets sleep in bed with you.  Treat dogs and cats for fleas regularly. Flea collars have not been proven effective. Do not allow pets to hunt or roam in rodent areas, such as prairie dog colonies. Keep pet food in rodent-proof containers. "If you develop symptoms of plague, see a health care provider immediately. Plague can be treated successfully with antibiotics, but an infected person must be treated promptly to avoid serious complications or death,” said Alicia Solis, program manager of the Office of Communicable Disease and Emergency Preparedness at PDPHE.