It is the deadliest foodborne illness outbreak since the Centers for Disease Control and Prevention began keeping records.
Unsanitary conditions in a Colorado packing facility are suspected as a contributing cause of the listeria.
More than 100 people have gotten sick in 28 states, and one pregnant woman had a miscarriage after eating the tainted cantaloupe.
The fruit was taken off shelves several weeks ago, but symptoms can take up to two months to appear.
