A man hospitalized in Bend is likely suffering from the plague, marking the fifth case in Oregon since 1995.

The unidentified man, who is in his 50s, fell ill several days after being bitten while trying to get a mouse away from a stray cat. The man is now being treated at St. Charles Medical Center-Bend, where he was listed in critical condition on Tuesday.

"This can be a serious illness," said Emilio DeBess, Oregon's public health veterinarian. "But it is treatable with antibiotics, and it's also preventable."

The Black Death raged through Europe during the Middle Ages, killing about a third of the population. Today, the disease is rare, but the bacteria have never disappeared.

The man, who lives in rural Crook County, was bitten Saturday, June 2. He developed afever a few days later. By Friday, June 8, he was so sick that he checked himself into St. Charles Medical Center-Redmond. He was later transferred to the larger facility in Bend.

Karen Yeargain, communicable disease coordinator with

, said lab tests are being done to confirm whether the man has the plague, but she said he is suffering from classic symptoms.

There's one bacterium that causes the disease -- Yersinia pestis -- but it can develop into three types of illnesses depending on how an individual's body reacts. Initially, the man had swollen lymph nodes -- a sign of bubonic plague -- but now he's showing signs of septicemic plague, when the bacteria multiply in the bloodstream. Symptoms include abdominal pain, bleeding mouth, nose or rectum and dying tissue. The