Three More Cases of Deadly Plague Found in Colorado

Three more cases of plague were found in Colorado after a man was reported to have the deadliest form of the disease last week.

The man who got pneumonic plague is hospitalized. He is thought to have contracted the infection from his dog that was likely exposed to plague-infected fleas in eastern Adams County, near Denver. The three additional residents also had direct contact with the dog and had mild symptoms, according to the Colorado Department of Public Health and Environment in a statement today. They were treated with antibiotics, recovered, and are no longer contagious, the state agency said.

Three of the cases are the first of pneumonic plague the state has seen in a decade, according to Jennifer House, a spokeswoman for the department. Colorado has had 60 cases of all types of plague since 1957, and nine people have died, the state said. One of the four cases had a milder form of the infection.

Plague in all of its forms infects only about seven people yearly in the U.S. The disease occurs when a bacterium named Yersinia pestis infects the body, according to the U.S. Centers for Disease Control and Prevention.

The difference between the pneumonic and bubonic varieties is that the bacteria takes hold in the lungs in the first case, rather than underneath the skin through insect bites. Pneumonic plague can be spread through coughing and sneezing. Both types are treated with antibiotics.