An upcoming article in the journal Emerging Infectious Diseases entitled "Zoonoses in the bedroom" has attracted some attention in the press. I haven’t been able to access a copy yet, but will probably write about it soon. However, one article that was written about the paper had a pretty weak lead-in piece:

"Nikki Moustaki knew something was wrong when she got strep throat for the sixth time in a year. Her doctor wanted to take out her tonsils. But Moustaki, an otherwise healthy 30-something, was determined to uncover the source of the infection. "I saw a bunch of specialists, and one suggested my dog might be a carrier," said Moustaki, a New York City-based dog expert and trainer. "I had never thought of that. When you think of contagious diseases in dogs you think of rabies and ringworm, you don’t think of strep." After four walks a day on the streets of Hell’s Kitchen, Moustaki’s dogs — a schnauzer called Pepper and Ozzie, a schnoodle — would curl up beside her in bed. Following her doctor’s surprising suggestion, Moustaki started cleaning Pepper and Ozzie’s paws with baby wipes after each walk. And she’s been strep-free ever since."

While it’s good to see the potential role of pets in human disease considered (since it’s often overlooked), this is a example of the opposite end of the spectrum: implicating pets with absolutely no evidence, and actually, contrary to all available evidence. Saying that cleaning her dogs’ feet prevented her from getting strep throat makes little sense on many levels. Firstly, if it actually made the difference, then she wasn’t really getting strep from the dogs, it was coming into the house on the dogs’ feet from the ground outside. There’s no evidence the outdoor environment is a relevant source of strep. If strep was present on the dogs’ feet, it would have to make it to her nose and mouth, and that degree of contact is hopefully unlikely (and if present, it would be associated with a lot bigger concerns that strep). Further, despite various studies, there is no evidence that dogs are even rare reservoirs of Group A Streptococcus, the cause of strep throat. Recurrent strep throat in people is caused by repeated exposure to infected people.

Like I said, it’s good to see recognition of the potential role of pets. The next step, however, has to be looking for the evidence. It’s not hard to find a few good references that talk about the role (or lack thereof in this case) of pets in human strep infections. Implicating the pet and recommending a rather bizarre foot hygiene regimen isn’t really helping anyone.

Is it just coincidence that the infections have stopped in this woman? Probably. Recurrent infections don’t tend to go on forever. However, maybe her increased attention to cleaning her dogs’ paws also led to her paying more attention (consciously or otherwise) to her own hygiene practices, which would have probably played a greater role in disease prevention.

(click image for source)