Fleas collected in Picture Canyon have tested positive for plague, according to Arizona public health officials.

Officials took notice of the dwindling prairie dog population in the popular hiking spot, and began to investigate the issue.

Since the finding, health officials have begun disinfecting prairie dog burrows in the area and conducting additional tests, according to AZfamily.com.

Area residents are being encouraged to protect themselves by using insect repellent. Officials are advising the public not to come into contact with sick or dead animals.

The discovery is the first sign of plague activity in the county since last September in Doney Park when the same thing occurred and plague-infected fleas were found in prairie dog holes.

Symptoms of the plague include fever, chills, swollen lymph glands and muscle pain, and can appear two to six days after the first exposure.

The disease is found in rodents, rabbits and predators that feed upon these animals. It can be transferred to humans by a bite from an infected flea or animal. The plague can be life-threatening if left untreated.

Officials will continue to scan the affected areas and re-treat them.