Squirrel parapoxvirus

Squirrel poxvirus is a virus that causes a fatal disease "squirrelpox" in UK red squirrels. The virus is often carried by grey squirrels from North America, which rarely die from the disease. Elsewhere in the Red Squirrel's European range, either the grey squirrel does not occur or it lacks the poxvirus hence the disease only occurs in the UK.

Overview

Grey squirrels very rarely die from this disease as their population has developed immunity having been exposed to the virus for many years; however, they are still carriers of the infection and can spread the disease to red squirrels. In sharp contrast, there are no known red squirrels that have developed immunity to the disease, and the mortality rate for untreated infected squirrels in the wild appears to be 100%;There has been some more recent anecdotal evidence on resistance to Squirrel pox in the red population including the finding of a healthy red squirrel with antibodies to the virus in Cumbria . However the mortality rate is still considered severe, and certainly capable of local extinction of red squirrels in areas that succumb to the disease.

Taxonomy

The official ICTV acronym for squirrel parapoxvirus is SPPV. The classification of the virus is still under debate, and the recent...
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