[Table of Contents]

Volume: 24S5 - September 1998

Canadian Integrated Surveillance Report for 1995 on Salmonella,
Campylobacter and Pathogenic Escherichia coli

Appendix A : Data Sources

Table of Contents

The data on human cases for this report were derived from the National Notifiable Diseases (NND) databases (Summary and Individual Case) and from the National Laboratory for Bacteriology and Enteric Pathogens (NLBEP) database; for non-human isolates the data came from the NLBEP and Health of Animals Laboratory (HAL) - Guelph. Detailed reports from these sources are also available: Notifiable Diseases Annual Report - 1995, Enteric Pathogens Identified in Canada During the Year 1995, and Salmonella Serovars and Salmonella Phagetypes Identified by the Health of Animals Laboratory at Guelph (1995).

For the NND Summary database, data were provided from the offices of provincial/territorial epidemiologists. Only cases that were "confirmed" (laboratory identification of organism) and "closed" (investigation completed) were reported. Reports included the number of cases of each disease by age and sex of the patients, province/territory of origin and month. No personal identifiers were provided. All data were verified at the provincial level. This required summarizing the monthly reports into an annual report for each province, sending the annual report back for verification and updating, and returning the verified report to LCDC.

For the NND Individual Case database, data were also provided from the  offices of provincial/territorial epidemiologists. Individual cases that were "confirmed" and "closed" were reported. The format of the reported data varied across the data providers. The required data elements were 1) the disease, 2) the province and 3) a date. The date provided varied from the date of diagnosis to the date the report was received. Other data were optional and were entered into the database if supplied.

For the NLBEP database, nearly all of the data concerning human isolates were obtained  from provincial laboratories, which received isolates from hospital, private, public and, in some cases, provincial veterinary laboratories for serotyping. These sources are requested to send all isolates of all notifiable agents, such as Salmonella, to the provincial laboratories, which in turn are requested to send data related to all notifiable agents to the national laboratory. Most of the data were submitted as individual case data. Approximately 32% of cases were submitted as aggregate data, but the proportion of aggregate data varied across the provinces, from 0% to 88%.

For individual cases, age, sex, province, the organism, and date isolated were included. Other data that may be associated with an isolate included submitting laboratory; date isolated; biochemical reactions; source (human or non-human); detail of source (non-human: poultry, egg, meat, water, feed, other, country of origin; human: A. stool, blood, urine, swab, other and B. enteric fever, gastroenteritis, septicemia, asymptomatic, unknown, other); case (isolated, outbreak, carrier); country of travel; patient's name; address; sex; age; province; and organism identification, serovar, phagovar, biovar and antimicrobial resistance pattern.

For aggregate data, the organism, number of cases, source (human or non-human), province and reporting date (month) were included. Other data that may have been recorded were phage type, serovar, and detail of source as specified above.

Non-human Salmonella isolates and data were sent to the national laboratory from the Health of Animals Laboratory (HAL) - Guelph, the Health Protection Branch (HPB) regional laboratories and provincial laboratories. The HPB laboratories received their samples from federal food inspection personnel (retail products and consumer complaints) and Medical Services Branch personnel (carrier food and federal institutions). Non-human isolates and data from provincial laboratories were mostly associated with animal clinical cases, production monitoring programs and special projects from provincial veterinary laboratories, but also included isolates associated with outbreak investigations. Some of the laboratories of Agriculture and Agri-Food  Canada, Animal and Plant Health Division (APHD), and Fisheries and Oceans Canada submitted a few isolates annually.

About two-thirds of the Salmonella isolates serotyped by HAL - Guelph were from environmental assessment or food quality programs (supply flocks, exportation, quality monitoring) and about one-third were disease-related. Provincial veterinary laboratory services and universities sent in about 800 isolates per year from clinical cases. The provincial laboratories also handled samples related to breeder programs and some disease control or special (e.g. specific meat process) projects. Agriculture and Agri-food Canada, APHD laboratories (Lethbridge, Saskatoon, Nepean, St-Hyacinthe, Charlottetown), sent in isolates related to meat processing plant samples, research projects, import/export testing of animals and environmental samples. Agriculture and Agri-food Canada, Laboratory Services Division (LSD) laboratories (Ottawa, Calgary), handled routine samples from feed, liquid eggs, dairy products, the environment of egg and dairy processing plants, and other food products. They sent Salmonella isolates to HAL for serotyping. Salmonella isolation on meat products was also done, at the Meat Bacteriology Laboratory at HAL. Most of the samples were from domestic meat products such as chicken and turkey parts. HAL also handled samples related to collaborative research projects. Some samples from outbreaks were also submitted to HAL.

Routine data recorded at HAL included source of isolation (animal source and type of sample), submitting laboratory, specimen number, date of collection, province or country (for specimen source), establishment (type and number), county or municipality, source (species or product), type of sample (e.g. swab, fluff, intestine), program, priority, serovar, phage type and biochemical characteristics.

This integrated report includes all cases or isolates reported in 1995 in the databases described, with the following exceptions: 1) research and laboratory quality isolates were excluded and 2) for time trend analyses, isolates that were from cases with onset or date of isolation before 1995 were excluded. The population estimates for 1995 were from Health Reports 1995, volume 6, which was prepared by the Demography Division, Population Estimates Section, Statistics Canada.

[Previous] [Table of Contents] [Next]