Pet Dog Infected Humans With the Plague in Colorado

By Gary Cutlack on at

A dog has managed to trigger a local plague outbreak in the US, after a poorly coughing pitbull terrier spread the germs to its owner and several vets called in to treat it.

The owner of the dog was infected by the animal first, when it started coughing up blood. Two of the vets that then treated the animal were also found to be infected with the plague-triggering Yersinia pestis virus, and after being misdiagnosed with bronchitis and pneumonia, eventually recovered.

More worrying for health authorities is that the virus appeared to spread between humans, with one vet who only handled the dead dog suspected of having contracted the virus from the owner -- which would make it the first person-to-person transmission of plague in the US for 90 years.

The agency explains the possibility of human-to-human transmission with:

"Three patients (A, B and C) became ill shortly after exposure to an ill infected dog. The source of infection for patient D is less certain because she had exposure to both the dog on June 25–26 (an incubation period of 9–10 days) and to patient A on June 29–30 while he had hemoptysis (an incubation period of 5–6 days). The shorter incubation period is more typical of plague and therefore supports human-to-human transmission."

According to the Centers for Disease Control and Prevention, a total of 114 people who had close contact with the infected group have been treated and placed under observation, lest the US become gripped by a plague panic. [CDC via Independent]

Image credit: Vet from Shutterstock