Stool submission data to help inform population-level incidence rates of enteric disease in a Canadian community

Abstract

Laboratory-based surveillance data is essential for monitoring trends in the incidence of enteric disease. Current Canadian human enteric surveillance systems report only confirmed cases of human enteric disease and are often unable to capture the number of negative test results. Data from 9116 hospital stool specimens from the Waterloo Region in Canada, with a mixed urban and rural population of about 500 000 were analysed to investigate the use of stool submission data and its role in reporting bias when determining the incidence of enteric disease. The proportion of stool specimens positive for Campylobacter spp. was highest in the 15-29 years age group, and in the 5-14 years age group for Salmonella spp. and E. coli O157:H7. By contrast, the age-specific incidence rates were highest for all three pathogens in the 0-4 years age group which also had the highest stool submission rate. This suggests that variations in age-specific stool submission rates are influencing current interpretation of surveillance data.

Time trends of positivity rates from foodborne pathogen testing in Switzerland, 2003 to 2012

“…Annual Salmonella positivity rates were similar or slightly higher for males than for females, with the highest rates observed in the younger age groups, <5, 5-9 and 10-14 years. The observed seasonality and annual trends of positivity rates for both pathogens are congruent with reports from other countries [14,18].…”

“…It was found that adults and the elderly suffered increasingly more frequently from campylobacteriosis; this could be related to the frequent use of proton pump inhibitors and comorbidities in these age groups [2,26,27]. Others have also observed increasing test numbers among the elderly and related it to changes (increases) in healthcare-seeking and physicians' testing behaviour [14,18,24]. Additionally, the Swiss population aged ≥85 years increased by 29% from 2003 to 2012, which probably also contributed to the observed increase in test numbers [28].…”

Global and regional source attribution of Shiga toxin-producingEscherichia coliinfections using analysis of outbreak surveillance data

“…The estimated relative contribution of each food type is dependent upon the probability that the food is involved in outbreaks that are identified and successfully investigated. For example, cases of severe illness or illness in children tend to be more frequently notified and cases of young adults less frequently [45]; this may also be true for outbreaks. Thus, certain risk groups within the larger population and smaller outbreaks may be underrepresented in the available data and more data are required to improve these estimates.…”

Physician practices in requesting stool samples for patients with acute gastroenteritis, France, August 2013–July 2014

“…Public health surveillance for different pathogens causing AG is dependent upon cases consulting for their illness, physicians requesting appropriate tests, identification of pathogens in laboratories and reporting of laboratory-confirmed cases to the public health authorities. Therefore physicians who request stool or other specimens for microbiological testing are essential contributors to the surveillance [1, 2]. A better understanding of the factors that influence General Practitioner (GP) diagnostic practices is needed to more accurately interpret laboratory-based surveillance data and the extent to which it underestimates the actual burden of disease.…”