What is botulism and how is it caused?

The bacteria behind the latest dairy milk formula scare, Clostridium botulinum, is often found in soil, untreated water and animal feces.

China recently suspended milk powder imports from New Zealand after exporter Fonterra discovered a strain of the bacteria that can cause botulism in some of its milk products.

Getting food-borne botulism is rare, but ingesting foods contaminated with the C. botulinum toxin can cause fatal illness.