New research sheds light on disease transmission in red foxes

A team of researchers has modelled the likely transmission methods for mange in foxes, for the first time.
Sarcoptic mange (Sarcoptes scabiei) is a common parasitic disease of wild and domestic animals and is known to decimate populations.

It is particularly common in wild canid species and has caused well known outbreaks in red foxes around the world. One of the best studied mange outbreaks occurred in urban foxes in Bristol.

A new study by Dr Carl Soulsbury at the University of Lincoln, with Dr Eleanor Devenish-Nelson, Dr Shane Richards, and Dr Phil Stephens at the University of Durham and Professor Stephen Harris at the University of Bristol, has modelled the likely transmission methods and pathways for the first time.

Contrary to expectations, disease transmission was not dependent on density (density-dependent transmission); when transmission rates increase with density of a population.

Instead epidemiological models more strongly support frequency-dependent transmission; meaning transmission rates do not change with density.

This is likely because fox behaviours limit interactions between and within fox social groups, and contrast with other species with less strict social groupings.

This new understanding of how mange can spread in populations will be crucial in managing this poorly understood but highly contagious and economically damaging disease.

Devenish-Nelson ES, Richards SA, Harris S, Soulsbury C, Stephens PA. 2014 ‘Demonstrating frequency-dependent transmission of sarcoptic mange in red foxes’ Biology Letters 10 : 20140524.
http://rsbl.royalsocietypublishing.org/content/10/10/20140524.full