Health officials in the capital of the Canadian province of New Brunswick are trying to get ahead of an outbreak of E. coli O157:H7 that has put two teenagers the hospital. A total of four confirmed cases are being investigated in Fredericton. The source of the bacteria remains a mystery. Victoria Boer, mother of one of the hospitalized teens, told CBC News that health officials are going through her daughter Micaella’s bank statements to figure out where she ate in the days before she fell ill with an E. coli infection. Tim Sly, an epidemiologist at Ryerson University, said he expects health officials will work around the clock until the source is found, and that efforts are “going full blast.” In April, the nearby New Brunswick town of Miramichi experienced an E. coli outbreak that infected 13 people, with another 11 possible cases. Miramichi is about two hours from Fredericton. The likely source of the April outbreak was romaine lettuce. In 2000, E. coli O157:H7 in the public water supply of the Ontario town of Walkerton killed 7 Canadians. Another 2,500 were sickened.