Could it be from unchecked illegal immigration of mud?

Polio-like illness found in five California children
By Jacque Wilson, CNN
updated 7:43 AM EST, Mon February 24, 2014

(CNN) -- Doctors are looking for more information about a "polio-like syndrome" that has caused paralysis in a few children in California.

Neurologists have identified five patients who developed paralysis in one or more of their limbs between August 2012 and July 2013. All five children had been vaccinated against the poliovirus. Treatment did not seem to help the children regain their motor function.

more http://www.cnn.com/2014/02/24/health/mystery-illness-in-california/