Are humans the initial source of canine mange?

Valérie Andriantsoanirina,Olivier Chosidow,Arezki Izri,Weiyi Huang,Charlotte Bernigaud,Fang Fang,Françoise Botterel,Jacques Guillot,Rémy Durand,Frédéric Ariey,Françoise Foulet

doi:10.1186/s13071-016-1456-y

Abstract

BackgroundScabies, or mange as it is called in animals, is an ectoparasitic contagious infestation caused by the mite Sarcoptes scabiei. Sarcoptic mange is an important veterinary disease leading to significant morbidity and mortality in wild and domestic animals. A widely accepted hypothesis, though never substantiated by factual data, suggests that humans were the initial source of the animal contamination. In this study we performed phylogenetic analyses of populations of S. scabiei from humans and from canids to validate or not the hypothesis of a human origin of the mites infecting domestic dogs.MethodsMites from dogs and foxes were obtained from three French sites and from other countries. A part of cytochrome c oxidase subunit 1 (cox1) gene was amplified and directly sequenced. Other sequences corresponding to mites from humans, raccoon dogs, foxes, jackal and dogs from various geographical areas were retrieved from GenBank. Phylogenetic analyses were performed using the Otodectes cynotis cox1 sequence as outgroup. Maximum Likelihood and Bayesian Inference analysis approaches were used. To visualize the relationship between the haplotypes, a median joining haplotype network was constructed using Network v4.6 according to host.ResultsTwenty-one haplotypes were observed among mites collected from five different host species, including humans and canids from nine geographical areas. The phylogenetic trees based on Maximum Likelihood and Bayesian Inference analyses showed similar topologies with few differences in node support values. The results were not consistent with a human origin of S. scabiei mites in dogs and, on the contrary, did not exclude the opposite hypothesis of a host switch from dogs to humans.ConclusionsPhylogenetic relatedness may have an impact in terms of epidemiological control strategy. Our results and other recent studies suggest to re-evaluate the level of transmission between domestic dogs and humans.

Highlights

Scabies, or mange as it is called in animals, is an ectoparasitic contagious infestation caused by the mite Sarcoptes scabiei [1,2,3,4]
A widely accepted hypothesis, though never substantiated by factual data, suggests that humans and protohumans were the initial source of animal contamination, dogs and other domestic animals being infested by human contacts and themselves a source for other species of wildlife [3, 4, 7, 25]
Other sequences corresponding to 50 mites from humans, raccoon dogs (Nyctereutes procyonoides) (n = 6), fox (n = 1), jackal (Canis aureus) (n = 1) and domestic dogs (n = 11) and from various geographical areas were retrieved from GenBank and from a previous study (Table 1)

Summary

Introduction

A widely accepted hypothesis, though never substantiated by factual data, suggests that humans were the initial source of the animal contamination. Mange as it is called in animals, is an ectoparasitic contagious infestation caused by the mite Sarcoptes scabiei [1,2,3,4] This neglected and emerging/ re-emerging disease is a significant public health problem worldwide with an estimated number of cases in humans of over 100 million in 2010 [5]. A widely accepted hypothesis, though never substantiated by factual data, suggests that humans and protohumans were the initial source of animal contamination, dogs and other domestic animals being infested by human contacts and themselves a source for other species of wildlife [3, 4, 7, 25]. In this study we performed phylogenetic analyses of populations of S. scabiei in humans and in canids to validate or not the hypothesis of a human origin of the mites infecting domestic dogs

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