Geographical Regions Of Canada Research Articles

Assessing social vulnerability and identifying spatial hotspots of flood risk to inform socially just flood management policy.

This study presents the first nationwide spatial assessment of flood risk to identify social vulnerability and flood exposure hotspots that support policies aimed at protecting high-risk populations and geographical regions of Canada. The study used a national-scale flood hazard dataset (pluvial, fluvial, and coastal) to estimate a 1-in-100-year flood exposure of all residential properties across 5721 census tracts. Residential flood exposure data were spatially integrated with a census-based multidimensional social vulnerability index (SoVI) that included demographic, racial/ethnic, and socioeconomic indicators influencing vulnerability. Using Bivariate Local Indicators of Spatial Association (BiLISA) cluster maps, the study identified geographic concentration of flood risk hotspots where high vulnerability coincided with high flood exposure. The results revealed considerable spatial variations in tract-level social vulnerability and flood exposure. Flood risk hotspots belonged to 410 census tracts, 21 census metropolitan areas, and eight provinces comprising about 1.7 million of the total population and 51% of half-a-million residential properties in Canada. Results identify populations and the geographic regions near the core and dense urban areas predominantly occupying those hotspots. Recognizing priority locations is critically important for government interventions and risk mitigation initiatives considering socio-physical aspects of vulnerability to flooding. Findings reinforce a better understanding of geographic flood-disadvantaged neighborhoods across Canada, where interventions are required to target preparedness, response, and recovery resources that foster socially just flood management strategies.

Antimicrobial Resistance of Campylobacter in Broiler Chicken Along the Food Chain in Canada

Antimicrobial resistance (AMR) is a major public health threat worldwide. The main objective of this study was to compare AMR in Campylobacter from broiler chickens raised on Canadian farms and their products in different geographical regions of Canada. To do this, antimicrobial susceptibility results from isolates of Campylobacter recovered from a national microbiological baseline study conducted in federally registered establishments and in the retail marketplace were analyzed. Among 1460 isolates tested, 774 (53%) were resistant to at least one antimicrobial, with a predominance of three profiles: tetracycline (39%), quinolone–tetracycline (6.6%), and quinolones only (3.5%). The results showed no significant difference in the frequency of resistant profiles (p ≥ 0.05) among the isolates originating from different points in the food processing chain at slaughterhouses and in retail establishments. This suggests that AMR observed in Campylobacter isolates from raw chicken at retail originated further upstream in the system. A difference in the frequency of certain resistance profiles was observed between the regions of Canada. For instance, in British Columbia, there was more resistance to quinolones, while in Ontario and Quebec, Campylobacter isolates were more resistant to tetracyclines, macrolides, ketolides, and lincosamides. Comparison of AMR data from this study with those from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) did not show any significant difference and provides evidence that CIPARS produces nationally representative resistance results.

Identification of a preferred statistical distribution for at-site flood frequency analysis in Canada

Floods are the most frequent natural disaster in Canada, putting Canadian lives and property at risk. Projected variations in precipitation and temperature are expected to further intensify extreme events, necessitating improved flood planning and water resource management. The Natural Sciences and Engineering Research Council funded FloodNet project is developing a standardized flood estimation manual for Canada; such a nation-wide manual would make flood frequency application more effective, consistent, and reproducible, reducing the need for subjective judgement. This research investigates a preferred at-site flood frequency distribution for Canadian annual peak flow dataset. Four frequently used distributions: Generalized Logistic distribution, Generalized Extreme Value distribution, and Pearson Type III distributions with and without log transformation, are assessed using two robust goodness-of-fit tests (i.e., Modified Anderson-Darling test and L-Moment test) across a wide range of Canadian annual peak flood samples. Goodness-of-fit assessments are analysed using different configurations of flood samples, including annual maximum flow and instantaneous peak flow samples, stationary samples and de-trended non-stationary samples, samples with varied record length, and samples from various geographical regions of Canada. Estimated flood quantiles are compared with estimates of hypothetical true quantiles to assess predictive performance of the considered distribution. Results show the Generalized Extreme Value distribution is better than the other considered distributions because of its acceptance for most station samples and the closeness to the estimates of hypothetical true quantiles. This study provides a basis for recommending the Generalized Extreme Value distribution for at-site flood frequency analysis in Canada.

PCR ribotyping and antimicrobial susceptibility testing of isolates of Clostridium difficile cultured from toxin-positive diarrheal stools of patients receiving medical care in Canadian hospitals: the Canadian Clostridium difficile Surveillance Study (CAN-DIFF) 2013–2015

Clostridium difficile toxin-positive diarrheal stool specimens submitted to eight Canadian hospital laboratories from 2013 to 2015 were cultured. Polymerase chain reaction ribotyping of isolates was performed using an internationally standardized, high-resolution capillary gel-based electrophoresis protocol and antimicrobial susceptibility testing conducted by CLSI-defined agar dilution (M11-A8, 2012). Among the 1310 isolates of C. difficile cultured, 141 different ribotypes were identified; the most common ribotypes were 027 (24.5% of isolates), 014 (7.7%), 020 (6.6%), 106 (6.1%), and 002 (4.6%). Ribotype 027 was the commonest ribotype in all geographic regions of Canada and was more frequently isolated from patients aged ≥80 years (40.6%) than younger patients (P<0.00001). Ribotype 027 isolates were frequently moxifloxacin-resistant (92.2% of isolates) and multidrug-resistant (49.5%). Fidaxomicin demonstrated the greatest in vitro potency (lowest MIC90, 0.5 μg/mL; lowest maximum MIC, 2 μg/mL) of eight antimicrobial agents tested and was the most active agent against each of the five commonest ribotypes (MIC90, 0.25–1 μg/mL).

Ochratoxin A Concentrations in a Variety of Grain-Based and Non–Grain-Based Foods on the Canadian Retail Market from 2009 to 2014

The extent of ochratoxin A (OTA) contamination of domestically produced foods sold across Canada was determined from 2009 to 2014 with sampling and testing occurring each fiscal year. Cereal-based, fruit-based, and soy-based food samples (n = 6,857) were analyzed. Almost half of the samples (3,200; 47%) did not contain detectable concentrations of OTA. The remaining 3,657 samples contained OTA at 0.040 to 631 ng/g. Wheat, oats, milled products of other grains (such as rye and buckwheat), and to a lesser extent corn products and their derived foods were the most significant potential sources of OTA exposure for the Canadian population. Wine, grape juice, soy products, beer, dairy-based infant formula, and licorice candy were not significant contributors to OTA consumption. Spices had the highest OTA concentrations; but because so little is ingested, these foods are not considered to be a significant source of OTA. In contrast, infant formulas and cereals can be important dietary sources of OTA. Infant cereals containing oats and infant formulas containing soy had detectable concentrations of OTA, some of which exceeded the proposed Canadian guidelines. The prevalence and concentrations of OTA in major crops (wheat, corn, and oats) varied widely across years. Because these foods were purchased at retail stores, no information was available on the OTA concentrations in the raw materials, the storage conditions before purchase of the samples, or the origin of the ingredients (may include blends of raw materials from different years and/or different geographical regions of Canada); therefore, impact of these factors could not be assessed. Overall, 2.3% of the samples exceeded the proposed Canadian OTA regulatory limits and 2.7% exceeded the current European Union (EU) OTA regulatory limits. These results are consistent with a Health Canada exposure assessment published in 2010, despite the inclusion of a wider range of products and confirm the safety of foods widely available across Canada.

Preface to the Special Issue on Floods in Canada

Floods are widely recognized as a common and largely distributed natural hazard with potential for causing loss of life, property damage, disruption of the economy and environmental damages. All geographic regions of Canada are susceptible to the deleterious impacts of floods. Recent flood events in Canada and elsewhere have contributed to the common perception that floods and associated damages have been increasing in recent years. Given the ubiquitous nature of this hazard, a thorough examination of the many complex and interrelated aspects of natural and man-made floods in Canada is long overdue. This special issue contains 27 papers dealing with a variety of different aspects of floods in Canada. The first 16 papers deal with physical aspects of floods and include a collection of case study papers that present recent flood events in Canada, following a common format to allow readers to compare and contrast recent flood events in different regions of Canada. The last 11 papers focus on ecological, social and management aspects of floods. The papers included in this special issue present topical information on flooding and also challenge common perceptions of floods and flood processes in Canada.

Geographic and facility variation in initial use of non-tunneled catheters for incident maintenance hemodialysis patients

BackgroundNon-tunneled (temporary) hemodialysis catheters (NTHCs) are the least-optimal initial vascular access for incident maintenance hemodialysis patients yet little is known about factors associated with NTHC use in this context. We sought to determine factors associated with NTHC use and examine regional and facility-level variation in NTHC use for incident maintenance hemodialysis patients.MethodsWe analyzed registry data collected between January 2001 and December 2010 from 61 dialysis facilities within 12 geographic regions in Canada. Multi-level models and intra-class correlation coefficients were used to evaluate variation in NTHC use as initial hemodialysis access across facilities and geographic regions. Facility and patient characteristics associated with the lowest and highest quartiles of NTHC use were compared.ResultsDuring the study period, 21,052 patients initiated maintenance hemodialysis using a central venous catheter (CVC). This included 10,183 patients (48.3 %) in whom the initial CVC was a NTHC, as opposed to a tunneled CVC. Crude variation in NTHC use across facilities ranged from 3.7 to 99.4 % and across geographic regions from 32.4 to 85.1 %. In an adjusted multi-level logistic regression model, the proportion of total variation in NTHC use explained by facility-level and regional variation was 40.0 % and 34.1 %, respectively. Similar results were observed for the subgroup of patients who received greater than 12 months of pre-dialysis nephrology care. Patient-level factors associated with increased NTHC use were male gender, history of angina, pulmonary edema, COPD, hypertension, increasing distance from dialysis facility, higher serum phosphate, lower serum albumin and later calendar year.ConclusionsThere is wide variation in NTHC use as initial vascular access for incident maintenance hemodialysis patients across facilities and geographic regions in Canada. Identifying modifiable factors that explain this variation could facilitate a reduction of NTHC use in favor of more optimal initial vascular access.

Examination of hospital length of stay in Canada among patients with acute bacterial skin and skin structure infection caused by methicillin-resistant Staphylococcus aureus.

PurposeSkin infections, particularly those caused by resistant pathogens, represent a clinical burden. Hospitalization associated with acute bacterial skin and skin structure infections (ABSSSI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is a major contributor to the economic burden of the disease. This study was conducted to provide current, real-world data on hospitalization patterns for patients with ABSSSI caused by MRSA across multiple geographic regions in Canada.Patients and methodsThis retrospective cohort study evaluated length of stay (LOS) for hospitalized patients with ABSSSI due to MRSA diagnosis across four Canadian geographic regions using the Discharge Database. Patients with ICD-10-CA diagnosis consistent with ABSSSI caused by MRSA between January 2008 and December 2014 were selected and assigned a primary or secondary diagnosis based on a prespecified ICD-10-CA code algorithm.ResultsAmong 6,719 patients, 3,273 (48.7%) and 3,446 (51.3%) had a primary and secondary diagnosis, respectively. Among patients with a primary or secondary diagnosis, the cellulitis/erysipelas subtype was most common. The majority of patients presented with 0 or 1 comorbid condition; the most common comorbidity was diabetes. The mean LOS over the study period varied by geographic region and year; in 2014 (the most recent year analyzed), LOS ranged from 7.7 days in Ontario to 13.4 days in the Canadian Prairie for a primary diagnosis and from 18.2 days in Ontario to 25.2 days in Atlantic Canada for a secondary diagnosis. A secondary diagnosis was associated with higher rates of continuing care compared with a primary diagnosis (10.6%–24.2% vs 4.6%–12.1%).ConclusionThis study demonstrated that the mean LOS associated with ABSSSI due to MRSA in Canada was minimally 7 days. Clinical management strategies, including medication management, which might facilitate hospital discharge, have the potential to reduce hospital LOS and related economic burden associated with ABSSSI caused by MRSA.

How important are determinants of obesity measured at the individual level for explaining geographic variation in body mass index distributions? Observational evidence from Canada using Quantile Regression and Blinder-Oaxaca Decomposition

BackgroundObesity prevalence varies between geographic regions in Canada. The reasons for this variation are unclear but most likely implicate both individual-level and population-level factors. The objective of this study was...

Temporal trends in the relative survival among patients diagnosed with ovarian cancer in Canada 1992–2005: A population-based study

ObjectiveOvarian cancer affects about 2600 women annually in Canada and about 1750 are expected to die from this disease. We estimated the trends in the relative survival ratio for patients diagnosed with epithelial invasive ovarian cancer in Canadian population between 1992 and 2005. MethodsA flexible parametric model was used to estimate the relative survival ratio. Relative survival ratio is defined as the observed survival among cancer patients divided by the expected survival in the general population. We incorporated age group, histology of tumour, and region of patient residence at the time of diagnosis into a model to predict two- and five-year relative survival ratios based on the year of diagnosis where the effect of each variable was adjusted for the effects of the other variables. A restricted cubic splines with five knots was used to include year of diagnosis in the model. ResultsIn total 7771 patients diagnosed with epithelial invasive ovarian cancer were included in this analysis with the mean age of 59.6 (SD=13.5) years at the time of diagnosis. About 75% of the patients were 50years and older at the time of diagnosis and relative survival ratio substantially decreased with age. The tumour type was serous for 43% of cases followed by endometrioid (30.5%), clear cell (14.5%), mucinous (9.5%), and transitional cell (2.5%). The same pattern was observed for all regions although with some variation in the proportions. The worst survival observed for serous tumours. About 50% of the cases were diagnosed in Ontario. ConclusionsThis is the first report that compares relative survival ratio for epithelial invasive ovarian cancer among geographic regions of Canada where a higher relative survival ratio was observed in Ontario compared to the other regions. The relative survival decreased with age and showed geographic variation. The work indicates that advances in management of women with ovarian cancer have improved two- and five-year relative survival ratios.

Exploring patient demographic and clinical characteristics associated with lipid-lowering pharmacotherapy use in primary care

Lipid-lowering therapeutics, particularly HMG Co-A reductase inhibitors, can be beneficial in primary and secondary cardiovascular prevention. The Canadian population frequently uses these medications but the manner in which they are used in community-based practice is unknown. To assess the patient characteristics associated with lipid lowering drug use in community-based clinical practice across four geographic regions in Canada. To assess amongst lipid-lowering drugs users the proportion of patients that would meet accepted dyslipidemia management guidelines. To assess the community-based effectiveness of anti-hyperlipidemic drugs. Patients filling a prescription for any anti-hyperlipidemia therapy in selected pharmacies in Ontario (ON), Quebec (PQ), British Columbia (BC) and Nova Scotia (NS). All eligible patients were interviewed over the telephone. Physicians who were providing healthcare to the participating patients were requested to provide information from the patient's medical record. The mean patient age was > 60 yr in all four provinces. There were some differences amongst the four provinces pertaining to patient characteristics, prescription patterns and therapeutic indicators, but not to outcomes. Anti-hyperlipidemia therapy was associated with a 1.81 mmol/L decrease in LDL-Cholesterol (P < 0.001); however only 73% of patients achieved target LDL-Cholesterol concentrations. A lag time of 1.96 yr (P < 0.0001) was observed from the diagnosis of dyslipidemia until the drug treatment was initiated. Patients had an average of 2.8 cardiovascular (CV) risk factors and 86% of patients had at two or more CV risk factors. Thirty-nine percent (95% CI, 36% - 42%) of the patients were being treated for secondary prevention. Thirteen percent (11-16%) of patients who were being treated for primary prevention had diabetes. Metabolic syndrome was observed in 32% (29-35%) of patients. Almost all patients fulfilled guideline requirements for the use of anti-hyperlipidemic therapy. Although the use of pharmacotherapy was associated with a lowering of LDL cholesterol more aggressive management is required to attain target LDL cholesterol concentrations.

Estimation of Representative Capital and Maintenance Costs for Canadian Roads

Procedures are described for estimating annualized life-cycle costs of road infrastructure for road classes and geographical regions of Canada. Estimated costs are total annualized costs required for constructing and maintaining road infrastructure. Total costs include initial construction costs for pavements, bridges, and other road infrastructure components; subsequent maintenance rehabilitation costs; and costs of routine and winter maintenance. The work is part of the Full Cost Investigation Project currently under way by Transport Canada. This project assesses total transportation costs for transportation modes in Canada. Total annualized road costs were estimated for 1-km-long, one-lane road segments selected to represent the entire Canadian provincial and municipal road network. Estimates were completed for 196 representative road segments covering 14 road functional classes in 14 geographical regions. Cost estimates were expressed as equivalent uniform annual costs and were carried out with an Excel-based computational model, which uses quantities and unit costs of dozens of road infrastructure components. Quantities and unit costs were established through surveys of Canadian federal, provincial, territorial, and municipal agencies; documentation review; and engineering judgment. Annualized costs for building and maintaining road infrastructure estimated by the model were compared with actual annual capital and maintenance expenditures reported by Canadian transportation agencies. Results indicate a basic correspondence between annualized costs estimated by the model and annual expenditures reported by transportation agencies, particularly for annual operating costs.

Residence location and likelihood of kidney transplantation

In a universal, public health care system, access to kidney transplantation should not be influenced by residence location. We determined the likelihood of kidney transplantation from deceased donors among Canadian dialysis patients living in 7 geographic regions. Within each region we also determined whether distance from the closest transplant centre was associated with the likelihood of transplantation. A random sample of 7034 subjects initiating dialysis in Canada between 1996 and 2000 was studied. We used Cox proportional hazards models to examine the relation between residence location and the likelihood of kidney transplantation from deceased donors over a median period of 2.4 years. There were significant differences in the likelihood of kidney transplantation from deceased donors and predicted waiting times between the different geographic regions. For example, the adjusted relative likelihood of transplantation in Alberta was 3.74 (95% confidence interval [CI] 2.95-4.76) compared with the likelihood in Ontario (p < 0.001). These differences persisted after further adjustment for differences in the rate of deceased organ donation. Within regions, patients who resided 50.1-150 km, 150.1-300 km and more than 300 km from the closest transplant centre had a similar adjusted likelihood of receiving a kidney transplant as those who lived less than 50 km away. The adjusted likelihood of undergoing a kidney transplant from a deceased donor varied substantially between geographic regions in Canada. In contrast, the likelihood of transplantation within regions was not affected by distance from the closest transplant centre.

Canadian Researchers Celebrate Country's Neuroscience Legacy

Canadian Researchers Celebrate Country's Neuroscience Legacy

Avoidable mortality across Canada from 1975 to 1999.

BackgroundThe concept of 'avoidable' mortality (AM) has been proposed as a performance measure of health care systems. In this study we examined mortality in five geographic regions of Canada from 1975 to 1999 for previously defined avoidable disease groups that are amenable to medical care and public health. These trends were compared to mortality from other causes.MethodsNational and regional age-standardized mortality rates for ages less than 65 years were estimated for avoidable and other causes of death for consecutive periods (1975–1979, 1980–1985, 1985–1989, 1990–1994, and 1995–1999). The proportion of all-cause mortality attributable to avoidable causes was also determined.ResultsFrom 1975–1979 to 1995–1999, the AM decrease (46.9%) was more pronounced compared to mortality from other causes (24.9%). There were persistent regional AM differences, with consistently lower AM in Ontario and British Columbia compared to the Atlantic, Quebec, and Prairies regions. This trend was not apparent when mortality from other causes was examined. Injuries, ischaemic heart disease, and lung cancer strongly influenced the overall AM trends.ConclusionThe regional differences in mortality for ages less than 65 years was attributable to causes of death amenable to medical care and public health, especially from causes responsive to public health.

Improving Population Attributable Fraction Methods: Examining Smoking-attributable Mortality for 87 Geographic Regions in Canada

Smoking-attributable mortality (SAM) is the number of deaths in a population caused by smoking. In this study, the authors examined and empirically quantified the effects of methodological problems in the estimation of SAM through population attributable fraction methods. In addition to exploring common concerns regarding generalizability and residual confounding in relative risks, the authors considered errors in measuring estimates of risk exposure prevalence and mortality in target populations and estimates of relative risks from etiologic studies. They also considered errors resulting from combining these three sources of data. By modifying SAM estimates calculated using smoking prevalence obtained from the 2000-2001 Canadian Community Health Survey, a population-based survey of 131,535 Canadian households, the authors observed the following effects of potential errors on estimated national SAM (and the range of effects on 87 regional SAMs): 1) using a slightly biased, mismatched definition of former smoking: 5.3% (range, 1.8% to 11.6%); 2) using age-collapsed prevalence and relative risks: 6.9% (range, 1.1% to 15.5%) and -15.4% (range, -7.9% to -21.0%), respectively; 3) using relative risks derived from the same cohort but with a shorter follow-up period: 8.7% (range, 4.5% to 11.8%); 4) using relative risks for all diseases with age-collapsed prevalence: 49.7% (range, 24.1% to 82.2%); and 5) using prevalence estimates unadjusted for exposure-outcome lag: -14.5% (range, -20.8% to 42.6%) to -1.4% (range, -0.8% to -2.7%), depending on the method of adjustment. Applications of the SAM estimation method should consider these sources of potential error.

Design of oligonucleotide arrays to detect point mutations: molecular typing of antibiotic resistant strains of Neisseria gonorrhoeae and hantavirus infected deer mice

Microarrays are promising tools for use in molecular diagnostics due to their ability to perform a multitude of tests simultaneously. In the case of genotyping many such tests will require discrimination of sequence at the single nucleotide level. A number of challenges exist including binding of optimal quantities of probe to the chip surface, the use of uniform hybridization conditions across the chip and the generation of labeled target. We investigated two model systems to test out the efficacy and ease with which probes can be designed for this purpose. In the first of these we designed primers to identify five mutations found in two genes from N. gonohorroeae, gyrA and parC that have been implicated in ciprofloxacin resistance. In the second system we used a similar strategy to identify four mutations in AT rich mitochondrial DNA from deer mice. These mutations are associated with deer mice subspecies that originate from different geographical regions of Canada and harbor different hantavirus strains. In every case we were able to design probes that could discriminate mutations in the target sequences under uniform hybridization conditions, even when targets were fairly long in length, up to 400 bp. Our results suggest that microarray analysis of point mutations might be very useful for automated identification and characterization of pathogens and their hosts.

The Efficacy of Intramammary Tilmicosin at Drying-off, and other Risk Factors for the Prevention of New Intramammary Infections during the Dry Period

The objective of this study was to compare the efficacy of an intramammary infusion, containing tilmicosin phosphate, to an infusion of a negative control intramammary placebo for preventing new intramammary infections (IMI) during the dry period. Cows were enrolled from 24 dairy herds from three geographical regions of Canada. Data from 248 cows and 938 bacteriologically negative quarters at drying-off are summarized. Overall, the rate of new IMI during the dry period was 16.7% of quarters. The new infection rates for quarters that received intramammary tilmicosin compared with the intramammary placebo were 14.4 and 19.4%, respectively. The majority of new IMI was caused by coagulase-negative staphylococci (49%) and environmental streptococcal organisms (26.8%). The probability for quarters to develop new IMI in the dry period was significantly increased when cows had higher milk production before drying-off (P = 0.04), when cows had longer dry periods (P = 0.02), and when dry cows were housed in tie-stall barns (P = 0.002). Higher parity cows and those that had a linear score somatic cell count (SCC) above 4 on the last DHI test were also at increased risk for new IMI (P<0.10). Administration of intramammary tilmicosin appears to be an efficacious therapy for prevention of new IMI; however, there is currently no approved intramammary formulation of this product available. Use of blanket dry cow antibiotic therapy compared to selective dry cow therapy, as well as the importance of identifying risk factors and managing the environment of dry cows are discussed.

The physiology and biochemistry of cold tolerance in arctic insects

Nine species of insects from three different geographical regions of Canada were examined for freezing tolerance, supercooling capacity, water content and changes in biochemical characteristics during acclimation to subzero temperatures. Six species proved to be freezing tolerant, the remaining three freezing susceptible. The majority of species in each category conformed to the generally recognized profiles of overwintering response. There were enough specific variations within each category, however, to indicate that cold tolerance mechanisms have evolved independently on a number of different occassions. Specific physiological and biochemical anomalies in these insects were discussed.

MAN AND INSECTS: THE INFLUENCE OF HUMAN SETTLEMENT ON THE INSECT FAUNA OF CANADA

AbstractBecause little is known of the pre-settlement insect fauna of Canada it is now almost impossible to assess all of the changes that have been caused by settlement. For most of the time that has elapsed since colonization began, settlements have been small and scattered, and land use has been non-intensive. Many refuges for native insects persisted until very recently, and many still persist but are diminishing. Thus probably few aboriginal species have been driven to extinction. Many ruderal and cultivated plants accompanied settlers from Europe and Asia. Some of these provide an expanded food supply for a few native insects and these have expanded their numbers and ranges. Other native insects have been displaced and diminished by depletion of forests and planting of crops. Exotic plants are inevitably accompanied by exotic insects and Canada has provided a hospitable home for a multitude of exotic insects. Over 300 species have been deliberately introduced for biological control.Once established in a colonial environment, the exotic origins of immigrant species are difficult to detect. Seven criteria for detecting exotic insect populations are suggested.The impacts of settlement on the principal geographic regions of Canada and their probable influence on insect faunas are briefly discussed.It is concluded that the insect fauna of Canada has been greatly enhanced by settlement.