At least 117 people in 34 states have gotten sick from salmonella infections. U.S. health officials believe two brands of cantaloupe — and dozens of fruit cups and medleys — may have been the cause.

Since the outbreak began in September, eight children have died — and there is no approved vaccine. But doctors are hopeful that public health measures may be enough to stop the spread.

Public health pandemics have captured all of our imaginations at one time or another. We take a look at some of the most persistent theories about...