'Needle in a haystack': Expert says finding daycare E. coli outbreak source complex

Health investigators and scientists are diving deep into food and fecal samples to zero in on the cause of an ongoing E. coli outbreak affecting Calgary daycares, but experts say definitive answers may be hard to come by. “You are trying to find the same organism with the same fingerprint,” said Timothy Sly, an epidemiologist and professor emeritus at Toronto Metropolitan University. There have been 264 lab-confirmed cases of the bacterial infection since the outbreak at 11 daycares