Tuesday, 7 December 2010

Human Scabies, Dog Mange and the Chupacabra - Is There a Connection?

Recent news stories about the legendary chupacabra, or goat sucker, identified the scabies mite, Sarcoptes scabiei, as the indirect culprit.

One artist's idea of what a chupacabra looks like.
Illustration by Alvin Padayachee

What is a Chupacabra?


A flurry of news stories appeared reporting on the identification of dead chupacabras as coyotes with severe mite infections. The same mite, reports said, causes scabies in humans and mange in dogs.

While providing a plausible explanation for a puzzling mystery, these stories may have caused some anxiety in readers who worry about catching things from household pets. What is the likelihood that these mites, which can apparently transform a coyote into a hairless, grotesque, and desperate livestock killer, could spread to a human and have a similar effect?

The Mange Mite and its Hosts


A little research reveals that, as reported, the same species of mite, Sarcoptes scabiei, infects people and a wide variety of animals. However, they don’t tend to jump from one type of host to another all that successfully. In fact, one 2007 study found that mite populations on chamois and red foxes in Italy were genetically distinct, suggesting that even closely related host species don’t cross infect each other (D. Soglia et al, “Microsatellites as markers for comparison among different populations of Sarcoptes scabiei.” Ital J. Anim Sci 6 (Suppl 1).


A coyote with mange is a sad-looking creature,
 and a sick one. USDA image.

Another study, reported in the American Journal of Tropical Medicine and Hygiene in 1999, compared mites from dog and human infestations. The researchers collected samples in the United States, Australia, and Panama and found that “genotypes of dog-derived and human-derived scabies cluster by host species rather than by geographic location” (S. F. Walton et al. “Genetically Distinct Dog-derived and Human-derived Sarcoptes scabiei in Scabies-endemic Communities in Northern Australia.”  Vol 61 [4]).

In other words, humans and dogs apparently aren’t sharing their mites much. Dogs and coyotes probably aren't either.

So while there are reports of people catching Sarcoptes scabiei from the family dog, this appears to be the exceptional circumstance. We don’t have to worry about becoming goat suckers any time soon.

2 comments:

  1. The Italian biologist showed in the 18th century that scabies is by the Sarcoptes scabiei variety hominis. is a genus of skin parasites and part of the larger family of mites collectively known as scab mites they are also related to the scab mite Psoroptes also a mite that infests the skin of domestic animals.

    ReplyDelete