There are a number of questions there.
One aspect is that as you're going through the food-borne outbreak and you're trying to follow it, one has a method of generating certain hypotheses as to what is the source of it, and one looks for evidence. One of the things we always try to do is make sure we don't focus too quickly. You look at other possibilities just in case, so you're not eliminating other possibilities.
Most of the time when they were serving these products, it's not clear whether they were serving them in sandwiches or not, or in what format in the homes, because you're asking people to recollect what they ate three to four weeks ago. And with elderly people in homes, their recall isn't good. Most of us would have trouble remembering what we ate two days ago. So there is that challenge that we don't have that same local outbreak.
The aspect is whether we question other things such as fresh-cut vegetables. Those were looked at as well. So we asked what the common thing was that would give the same bacteria in the fingerprinting. It was something that was in a nursing home here, one 300 kilometres over there, and another one 400 kilometres over there.
With the laboratory test that was evolving up through the fingerprinting and the PFGE typing, there was a debate on what the types were and how specific that typing was. Much like DNA used in early courtroom cases, it is like saying that if it is this one PFGE type, and if I have it and Dr. McKeown has it 300 kilometres away, what's the chance of that occurring by happenstance? Or is it so specific that it would be unlikely? There must be some common event that we experienced that connects it. We just have to look for it. That was what was evolving at that time.