C-EnterNet used the laboratory-based surveillance system for reportable illnesses in place in Ontario in which it is mandatory for clinical laboratories to 5-FU in vivo report each case of reportable disease to the local public health authority. C-EnterNet enhanced this system in ROW public health by implementing a systematic

follow-up of each reported case by a public health inspector using a standardized questionnaire (available at http://www.phac-aspc.gc.ca/c-enternet/pdf/campylobacter-w_e.pdf). Detailed information on demographics and disease symptoms, as well as exposure to 14 potential risk factors (including travel) which may have occurred during a given number of days prior to the disease onset (ie, the number of days is disease specific and accounts for varying length of incubation) was collected.

In addition, the enteropathogen isolates were forwarded to the Ontario Agency for Health Protection and Promotion’s Toronto Public Health Laboratory in Etobicoke, Ontario for further characterization depending on the pathogen genus. These laboratory results were then sent to the ROW public health authorities, who ultimately provided the depersonalized epidemiological and microbiologic data to C-EnterNet, Public Health Agency of Canada. Potential PF-562271 cell line duplicates were systematically checked and removed by ROW public health personnel through their routine work prior to providing the dataset to C-EnterNet. Ethics approval was provided through the ROW public health ethics review. Reported cases that could not

be reached for the follow-up interview were considered as lost to follow up and removed from the dataset (n = 145). Outbreak-related cases, as defined by ROW public health authority on the basis of epidemiological or laboratory evidence, were removed as well. The remaining cases were classified as either TRC or DC as follows. TRC were defined as cases for which travel outside Canada prior to the disease onset were recorded and the expected incubation period overlapped the travel time. More specifically, the delay between departure and onset dates had to be greater or equal to the minimum incubation period and the delay between return and onset dates less than the MTMR9 maximum incubation period. The minimum and maximum incubation periods were from Heyman:22 14 to 28 days for amebiasis, 1 to 10 days for campylobacteriosis, 1 to 12 days for cryptosporidiosis, 1 to 14 days for cyclosporiasis, 3 to 25 days for giardiasis, 15 to 50 days for hepatitis A, 0 to 3 days for non-typhoidal salmonellosis, 0 to 4 days for shigellosis, 7 to 21 days for typhoid and paratyphoid fever, 2 to 10 days for VTEC infection, and 3 to 7 days for yersiniosis. Cases not classified as TRC were considered as DC cases. In each record, a free text field allowed the public health inspector, responsible for case follow-up, to indicate his/her opinion on the probable source.