Someone posted that the MD officials were justified in killing the ferret on
the basis of a "one in a million" chance that it was infected.  First, is the
issue that 30 days had passed since the bite, far too long to begin
treatment.  Second is the fact that PH did not recommend the anti-rabies
series which they should have if they suspected that the ferret might have
carried rabies.
 
Now let's look at the odds.  One in a million?
 
Over the period from 1988 to 1992 there were 2 ferrets found with rabies.
 The ferret population in 1988 was estimated by AFA at somewhere near 8
million; in 1992, somewhere between 10 and 12 million. Let's take 9 million
as an average.
 
That would give you the odds of any one ferret being rabid of  1 in
22,500,000.
 
If the ferrets were vaccinated with IMRAB (about 95% effective) the odds of
any vaccinated ferret having rabies would be about 1 in 450,000,000.
 
Now let's assume that the Eurpean studies are totally wrong and instead of
not shedding the virus, let's assume a huge 30 day shedding period.  That
would give you the odds of envcountering any one vaccinated ferret during
that shedding period of  about 1 in 5,475,000,000.
 
Again let's assume that the European studies were wrong and at least some
developed the furious form of rabies.  Let's say 1 in 50.  Now you have the
odds of encountering  that vaccinated ferret with rabies during the shedding
period and it attacking you, of 1 in 273, 750, 000,000.
 
Finally the odds of a human developing rabies after being bitten by a rabid
animal is about 1 in 6.  Therefor the odds of getting rabies from that
vaccinated ferret would be about 1 in 1,642,500,000,000.
 
Dick Bossart
[Posted in FML issue 1106]