An article published in 1991 described the testing of 738 bottles of corn
syrup and other products containing corn syrup (e.g. pancake syrup).
None of the bottles contained c. botulinum spores.  It was noted in the
article that manufacturers had recently changed their processing to
eliminate botulinum spores.  This study was conducted in the US by the
Food and Drug Administration.  The reference is:  Lilly, T. et al.  (1991).
Clostridium botulinum spores in corn syrup and other syrups.  Journal of
Food Protection, 54(8):  585-587.  Also noted in the article was that
honey is the only confirmed food source of botulism in infants.