"Although some sick people reported eating romaine lettuce, preliminary data available at this time shows they were not more likely than healthy people to have eaten romaine, based on a CDC food consumption survey".
In the US, officials with the CDC, the FDA, and state public health authorities have been conducting interviews with the 17 people who have become ill in the USA outbreak, to learn what they ate in the week before their illness.
An E. coli outbreak linked to two deaths and dozens of illnesses in Canada and the United States continues to grow, with no clear answers on what's causing the life-threatening infections.
"Even though we can't say with 100 percent certainty that romaine lettuce is the cause of the E. coli outbreak in the USA, a greater degree of caution is appropriate given that romaine lettuce is nearly always consumed raw", said James Roger, food safety director at Consumer Reports as NBC notes.
Also, while romaine is the likely source of the outbreak, it has not yet been confirmed.
Canadian health officials have stopped short of ordering a recall of romaine lettuce until more is known about the cause of contamination.
"People in these groups should be particularly vigilant about avoiding romaine lettuce", Rogers said. But it's still a good idea to avoid the leafy green for now, whether it's sold fresh or in pre-packaged salad mixes.
"Even though we can't say with 100% certainty that romaine lettuce is the cause of the E. coli outbreak in the USA, a greater degree of caution is appropriate given that lettuce is nearly always consumed raw", says James Rogers, Ph.D., Director of Food Safety and Research at Consumer Reports.
But Chapman was less certain about this recommendation.
It should also be noted that washing your leaves thoroughly will not eliminate the problem as the bacteria can cling to nooks and crannies in the lettuce, as Consumer Reports warns.
The CDC says it is unable to recommend whether people should avoid a particular food while the source of the outbreak is still under investigation. The CDC is now interviewing sick people to determine what they ate in the week prior to getting sick.