The Centers for Disease Control and Prevention (CDC) released a case study on Thursday that documents a dog in Colorado infecting humans with pneumonic plague in the United States.
In June of 2014, a two-year-old American pit bull terrier became sick. The dog had a fever, jaw rigidity and exhibited drooling and neurological problems. The dog was taken to a local veterinarian where its health declined to the point that it was euthanized one day later.
Four days later, the dog’s owner showed up at a local hospital with a fever and bloody cough. On admission, blood cultures, and other diagnostic tests eventually led to a diagnosis of pneumonic plague. A friend of the owner and two employees of the veterinary office also became sick with the pneumonic plague.
Further blood tests on all four people and the dog were positive for Yersinia pestis. All four humans were treated with antibiotics and recovered.
What is unusual, in this study, is that this is the first time the CDC has ever reported a case of a dog transmitting the plague to a human. Dogs are usually asymptomatic or show very mild symptoms of the plague. Because one of the primary ways of spreading pneumonic plague is by sneezing, it is unlikely that a dog would be able to spread it to humans.
Study author Janine Runfola of the Tri-County Health Department in Colorado told ABC News, “For pneumonic plague, a more likely scenario would be you have a cat [play] with prairie dogs and infected fleas get on the cat. The cat gets sick and sneezes and coughs on its owner.”
There is another surprising revelation from this case study. According to NBC, as reported by newser, this is the first time in 90 years that the pneumonic plague may have been transferred from one human to another. A time-line of the contact with the friend of the owner and any interaction with the dog indicates it is more likely transmission of the disease came from the owner.
Plague is endemic to prairie dogs in the American Southwest. This has led to isolated pockets of outbreaks of the plague in animals and humans in the past.
