I don't quite understand the questions... you have a cramp in your toe, and you suspect it is caused by norovirus? I would doubt it, unless you injected your toe with the virus in which case you would have an immune reaction and maybe a swollen toe. Noroviruses are primarily gastro-intestinal. Actually, I suppose if you had a GI infection of norovirus, you could be depleted in salts from the vomiting and diarrhoea, which could give you cramps.
I don't get the question about passed strains either... perhaps you meant past (as in previous or prior to)? Evolution of strains is limited by the ability of the virus to proof-read its genome during replication, for this reason HIV mutates (RNA virus - no proof reading) faster than influenza (DNA, proof reading).
Edited by bob1, 06 July 2009 - 04:37 PM.