A report from the United States Food and Drug Administration says 515 Canadians were sickened last year by Salmonella Newport in red onions from the Imperial Valley of California.
There were 1,127 cases across the United States.
The FDA could not pin-point the source, but said irrigation water was likely responsible and may have been contaminated by wildlife or farm livestock.
It recommended farmers take more care in harvesting an packing red onions.
Dr. Doug Powell recalls on his website, Barfblog, that during a presentation on food safety, a grower said he blanched all his produce, but not onions because they had never been implicated in food recalls.
Red onions are used as an ingredient in many salads and other food products which explains why so many people were sickened.
