Just to explain and counter the recent press images re the similarities of
WNV with polio, here's some counter-propaganda, with an environmental
perspective:

1) Polio (the cultural icon), was supposed to be 'eradicated in 2000',
according to previous sales language that hyped the efficacy of mass
vaccination programs, however, recent press releases have polio, and the
poliovirus:

        a) continuing as a latent virus.
        b) having military potential, via a synthesized poliovirus
        c) misdiagnosed
        d) not really going away by 2000.

Industry just can't say goodbye to "polio" in 2000, as they claimed they
would (due to great vaccines), so it's being re-incorporated into the press
releases here and there, in various new forms.

2) Polio epidemics, the largest ones in the U.S. being in 1916 and
1945-1962, appear to have been due mainly to organochlorines in milk (as a
carrier) in 1916, or overexposure to persisitent pesticides in dairy and
other foods during the post-1945 era.  www.geocities.com/harpub   Not to say
that air pollution in those eras could not be a factor re polio.

3) Recently, the media is revealing WNV and polio as similar diseases.  That
should not be difficult since neither is limited to a narrow set of symptoms
and physiologies.  Both can range from silent, a common cold, the flu,
meningitis, encephalitis, and destruction of the anterior horn (upper region
of the spinal column, near the brain).

4) Differences:  WNV occurs mostly in the summer, and polio is nowadays less
limited to summer.  WNV matches air pollution day-for-day, whereas pesticide
exposure is more ubiquitous in time and place, meaning that pesticides would
have to be a background toxic factor, not directly causative as air
pollution is, for WNV.

Studies/graphs/sources for both polio and WNV, in terms of toxicology:

www.geocities.com/harpub  (Poliovirus)
www.geocities.com/noxot  (West Nile virus)

-Jim West