There is extensive information on ECE available at the Ferret Health List:
 
http://groups.yahoo.com/group/Ferret-Health-list
 
and at
 
http://www.afip.org/ferrets/index.html
 
as is information on a range of other health concerns.
 
No, ECE is not infectious from them for the rest of their lives, though the
infectious period is a long one.  Yes, some do have extensive intestinal
damage, or sometimes continued difficulties like kidney damage from
dehydration that can shorten or impair their lives.
 
It is currently very difficult to test for the presence of the ECE
coronavirus, so at this point that is restricted to related research.
So, no, your vet isn't going to have this ability readily handy, but,
yes, in unusual cases which interest the researchers or in ferrets with
complications which are under study currently testing may be possible,
but it is not easily done.  (See the pages given to learn why.)  There ARE
efforts underway to see if an affordable, easy, and widely available test
may be possible to devise for the future, as well as others to see if a
vaccine may be possible to devise.  Neither is at all a simple problem.
 
The most extensive information available publicly on ECE comes from
the veterinary pathologist, Bruce Williams.
[Posted in FML issue 3387]