Conversation so far:
What happened in 2012?
As of November 14, 2012, the Centers for Disease Control and Prevention (CDC) has confirmed 32 deaths and that 438 people have been sickened.
what were they sickened by?
the meningitis outbreak.

Question: What was the cause of the outbreak?
Self-contained rewrite: What was the cause of the 2012 Fatal Meningitis Outbreak outbreak?