The contaminated jars of the pasta sauce were thought to have contained the bacterium botulinum, a toxin which attacks a person’s nerves, local newspaper Il Secolo XIX reported. The symptoms include blurred vision, slurred speech and muscle weakness.
Ten people, including one child, are recovering in hospital after eating the sauce. A further 70 were seen by doctors and then dismissed, the newspaper said.
Hundreds of people have contacted health services for more information about the scare.
The news comes just two days after laboratory tests found a contaminated jar at local producer Bruzzone e Ferrari. The company immediately pulled all remaining jars of pesto from the shelves.