Environmental Investigation during Legionellosis Outbreak, Montérégie, Quebec, Canada, 2021.

In August 2021, a legionellosis outbreak involving 7 persons occurred within a 500-meter radius in the Montérégie region of Québec, Canada. Near real-time modeling of wind direction along with epidemiologic and environmental investigations identified the possible source. Modeling wind direction could help identify likely Legionella pneumophila sources during legionellosis outbreaks.

Behavioral risk factors associated with reported tick exposure in a Lyme disease high incidence region in Canada.

BACKGROUND: Tick-borne diseases, and especially Lyme Disease (LD), are on the rise in Canada and have been met with increasing public health concern. To face these emerging threats, education on the prevention of tick bites remains the mainstay of public health intervention. The objective of this study was to assess the adoption of preventive behaviors toward tick bites and LD and to investigate the association between behavioral risk factors and reported tick exposure in a Canadian, LD high incidence region (Estrie region, Quebec, Canada). METHODS: A cross-sectional study was conducted in 2018 which used a telephone questionnaire administered to a random sample of 10,790 adult residents of the study region. Questions investigated tick exposure, LD awareness, attitudes towards LD risk, outdoor and preventive behaviors, as well as antibiotic post-exposure prophylaxis (PEP) treatments in the case of a tick bite. Descriptive and multivariable analyses were carried out, considering the nine administrative subregions and the stratified survey design. RESULTS: The sub-regional prevalence of reported tick exposure in the previous year ranged from 3.4 to 21.9%. The proportion of respondents that adopted preventive behaviors varied from 27.0% (tick checks) to 30.1% (tick repellent) and 44.6% (shower after outdoor activities). A minority of respondents (15.9%) that sought healthcare after a tick bite received a PEP treatment. Performing tick checks (Odds ratio = 4.33), time spent outdoors (OR = 3.09) and living in a subregion with a higher public health LD risk level (OR = 2.14) were associated with reported tick exposure in multivariable models. CONCLUSIONS: This study highlights the low level of adoption of preventive behaviors against tick bites in a region where LD risk is amongst the highest in Canada. This suggests a concerning lack of improvement in LD prevention, as low levels of adoption were already reported in studies conducted in the last decade. Innovative and evidence-based approaches to improve education on ticks and tick-borne diseases and to promote behavior changes are urgently needed in Canada.

Economic Burden of West Nile Virus Disease, Quebec, Canada, 2012-2013.

The economic burden of West Nile virus (WNV) infection is not known for Canada. We sought to describe the direct and indirect costs of WNV infection in the province of Quebec, Canada, up to 2 years after onset of signs and symptoms. We conducted a retrospective cohort study that included WNV cases reported during 2012 and 2013. For 90 persons infected with WNV, persons with encephalitis accounted for the largest proportion of total cost: a median cost of $21,332 per patient compared with $8,124 for West Nile meningitis (p = 0.0004) and $192 for West Nile fever (p<0.0001). When results were extrapolated to all reported WNV patients, the estimated total cost for 124 symptomatic cases was ≈$1.7 million for 2012 and that for 31 symptomatic cases was ≈$430,000 for 2013. Our study provides information for the government to make informed decisions regarding public health policies and infectious diseases prevention and control programs.

Practices of Lyme disease diagnosis and treatment by general practitioners in Quebec, 2008-2015.

BACKGROUND: Lyme disease (LD), a multisystem infection caused by the spirochete Borrelia burgdorferi sensu stricto (B. burgdorferi), is the most reported vector-borne disease in North America, and by 2020, 80% of the population in central and eastern Canada could live in LD risk areas. Among the key factors for minimising the impact of LD are the accurate diagnosis and appropriate management of patients bitten by ticks. In this study, the practices of Quebec general practitioners (GPs) on LD diagnosis and management of patients bitten by infected ticks are described. METHODS: Eight years (2008 to 2015) of retrospective demographic and clinical data on patients bitten by infected Ixodes scapularis (I. scapularis) ticks and on the management of suspected and confirmed LD cases by Quebec GPs were analysed. RESULTS: Among 50 patients, all the antimicrobial treatments of LD clinical cases were appropriate according to current guidelines. However, more than half (62.8%) of erythema migrans (EM) were possibly misdiagnosed, 55.6%, (n = 27) of requested serologic tests were possibly unnecessary and the majority (96.5%, n = 57) of prophylactic antimicrobial treatments were not justified according to current guidelines. CONCLUSIONS: These observations underline the importance for public health to enhance the knowledge of GPs where LD is emerging, to minimise the impact of the disease on patients and the financial burden on the health system.

Acceptability of tick control interventions to prevent Lyme disease in Switzerland and Canada: a mixed-method study.

BACKGROUND: Lyme disease control strategies may include tick control interventions in high risk areas. Public authorities may be interested to assess how these types of interventions are perceived by the public which may then impact their acceptability. The aims of this paper are to compare socio-cognitive factors associated with high acceptability of tick control interventions and to describe perceived issues that may explain their low acceptability in populations living in two different regions, one being an endemic region for LD since the last 30 years, the Neuchâtel canton, in Switzerland, and another where the disease is emerging, the Montérégie region, in Canada. METHODS: A mixed methods' design was chosen. Quantitative data were collected using web-surveys conducted in both regions (n = 814). Multivariable logistic regressions were used to compare socio-cognitive factors associated with high acceptability of selected interventions. Qualitative data were collected using focus group's discussions to describe perceived issues relative to these interventions. RESULTS: Levels of acceptability in the studied populations were the lowest for the use of acaricides and landscaping and were under 50 % in both regions for six out of eight interventions, but were higher overall in Montérégie. High perceived efficacy of the intervention was strongly associated with high acceptability of tick control interventions. A high perceived risk about LD was also associated with a high acceptability of intervention under some models. High level of knowledge about LD was negatively associated with high acceptability of the use of acaricides in Neuchâtel. Perceived issues explaining low acceptability included environmental impacts, high costs to the public system, danger of individual disempowerment and perceptions that tick control interventions were disproportionate options for the level of LD risk. CONCLUSION: This study suggests that the perceived efficacy and LD risk perception may be key factors to target to increase the acceptability of tick control interventions. Community-level issues seem to be important considerations driving low acceptability of public health interventions. Results of this study highlight the importance for decision-makers to account for socio-cognitive factors and perceived issues that may affect the acceptability of public health interventions in order to maximize the efficacy of actions to prevent and control LD.

Factors associated with preventive behaviors regarding Lyme disease in Canada and Switzerland: a comparative study.

BACKGROUND: Lyme disease (LD) is a vector-borne disease that is endemic in many temperate countries, including Switzerland, and is currently emerging in Canada. This study compares the importance of knowledge, exposure and risk perception for the adoption of individual preventive measures, within and between two different populations, one that has been living in a LD endemic region for several decades, the Neuchâtel canton in Switzerland, and another where the disease is currently emerging, the Montérégie region in the province of Québec, Canada. METHODS: A web-based survey was carried out in both study regions (814 respondents) in 2012. Comparative analysis of the levels of adoption of individual preventive measures was performed and multivariable logistic regression analyses were used to test and compare how knowledge, exposure and risk perception were associated with the adoption of selected measures in both regions and globally. RESULTS: In Montérégie, the proportion of reported adoption of five of the most commonly recommended preventive measures varied from 6% for 'applying acaricides on one's property' to 49% for 'wearing protective clothing', and in Neuchâtel, proportions ranged from 6% (acaricides) to 77% for 'checking for ticks (tick check)'. Differences were found within gender, age groups and exposure status in both regions. The perceived efficacy of a given measure was the strongest factor associated with the adoption of three specific preventive behaviors for both regions: tick check, protective clothing and tick repellent. Risk perception and a high level of knowledge about LD were also significantly associated with some of these specific behaviors, but varied by region. CONCLUSIONS: These results strongly suggest that social and contextual factors such as the epidemiological status of a region are important considerations to take into account when designing effective prevention campaigns for Lyme disease. It furthermore underlines the importance for public health authorities to better understand and monitor these factors in targeted populations in order to be able to implement preventive programs that are well adapted to a population and the epidemiological contexts therein.

Lyme disease: Knowledge and practices of family practitioners in southern Quebec.

BACKGROUND: Public health authorities in Quebec have responded to the progressive emergence of Lyme disease (LD) with surveillance activities and education for family physicians (FPs) who are key actors in both vigilance and case management. OBJECTIVES: To describe FPs' clinical experience with LD, their degree of knowledge, and their practices in two areas, one with known infected tick populations (Montérégie) and one without (regions nearby Montérégie). METHODS: In the present descriptive cross-sectional study, FPs were recruited during educational sessions. They were asked to complete a questionnaire assessing their clinical experience with Lyme disease, their knowledge of signs and symptoms of LD, and their familiarity with accepted guidelines for diagnosing and treating LD in two clinical scenarios (tick bite and erythema migrans). RESULTS: A total of 201 FPs participated, mostly from Montérégie (n=151). Overall, results revealed a moderate lack of knowledge and suboptimal practices rather than systematically insufficient knowledge or inadequate practices. A majority of participants agreed to more education on LD. As expected, FPs from Montérégie had a higher clinical experience with tick bites (57% versus 25%), better knowledge of LD endemic areas in Canada and erythema migrans characteristics, and better management of erythema migrans (72% versus 50%). CONCLUSION: The present study documented the inappropriate intention to order serology tests for tick bites and the unjustified intention to use tick analysis for diagnostic purposes. Such practices should be discouraged because they are unnecessary and overuse collective laboratory and medical resources. In addition, public health authorities must pursue their education efforts regarding FPs to optimize case management.

HISTORIQUE: Les autorités en santé publique du Québec ont répondu à l'émergence progressive de la maladie de Lyme (ML) par des activités de surveillance et des formations pour les médecins de famille (MF), qui sont des acteurs majeurs en matière de vigilance et de prise en charge. OBJECTIFS: Décrire l'expérience clinique des MF à l'égard de la ML, leur degré de connaissances et leurs pratiques dans deux régions, l'une comptant des populations connues de tiques infectées (Montérégie) et l'autre n'en comptant pas (régions à proximité de la Montérégie). MÉTHODOLOGIE: Dans la présente étude transversale descriptive, les MF ont été recrutés pendant des séances de formation. Ils ont été invités à remplir un questionnaire visant à évaluer leur expérience clinique de la ML, leurs connaissances des signes et symptômes de cette maladie et leurs connaissances des directives acceptées pour diagnostiquer et traiter la ML pour deux scénarios cliniques (piqûre de tique et érythème migrant). RÉSULTATS: Au total, 201 MF ont participé, la plupart provenant de la Montérégie (n=151). Dans l'ensemble, les résultats ont révélé un manque modéré de connaissances et des pratiques sous-optimales plutôt que des connaissances systématiquement insuffisantes ou des pratiques inadéquates. La majorité des participants ont convenu avoir besoin de plus de formation sur la ML. Comme prévu, les MF de la Montérégie avaient une plus grande expérience clinique des piqûres de tique (57 % par rapport à 25 %), connaissaient mieux les régions endémiques de la ML au Canada et les caractéristiques de l'érythème migrant et prenaient mieux en charge l'érythème migrant (72 % par rapport à 50 %). CONCLUSION: La présente étude a permis de constater l'intention inappropriée de demander des tests sérologiques après une piqûre de tique et d'analyser les tiques pour corroborer le diagnostic de ML. Il faut décourager ces pratiques, car elles sont inutiles et favorisent la surutilisation collective des laboratoires et des ressources médicales. Par ailleurs, les autorités en santé publique doivent poursuivre leurs efforts de formation auprès des MF pour optimiser la prise en charge des cas.

From Lyme disease emergence to endemicity: a cross sectional comparative study of risk perceptions in different populations.

BACKGROUND: Lyme disease (LD) is a tick-borne emerging disease in Canada that has been endemic in many temperate countries for decades. Currently, one of the main approaches for LD prevention is the promotion of individual-level preventive behaviors against ticks. Health behaviors are influenced by individual and social factors, one important of which is risk perception. This study aims to describe and compare risk perception of LD, within and between general populations and experts living in two different regions: the Neuchâtel canton in Switzerland, where LD is endemic, and the Montérégie region in Québec (Canada), where LD is emerging. METHOD: A web-based survey was conducted in both study regions (814 respondents) in 2012, and a questionnaire was administered to 16 experts. Comparative analyses of knowledge, risk exposure and different components of LD risk perception were performed. Multivariate analyses were used to calculate a global risk perception score and to identify determinants of risk perception in both regions. RESULTS: In Montérégie, only 15% of the survey respondents had a good level of knowledge of LD compared to Neuchâtel where 51% of survey respondents had good levels of knowledge. In Montérégie, 24% of respondents perceived themselves as being at high or very high risk of contracting LD vs 54% in Neuchâtel; however, a higher percentage of respondents from this region believed that personal protection was simple to carry out (73% vs 58% in Montérégie). Based on the population surveys, almost all of the identified determinants of risk perception were different between both populations except for gender. A good level of knowledge, living in the risk zone and knowing someone who has had LD increased risk perception, while a high level of education and being 18-34 years of age decreased this perception. The majority of the studied components of risk perception were different between populations and their regional experts. CONCLUSION: This study suggests that risk perception of LD differs between populations and regional experts living in different epidemiological situations. Monitoring of knowledge and risk perception in local populations may help to better target LD communication efforts in accordance with population specific attributes thereby enhancing prevention efficacy.

Self-reported tick exposure as an indicator of Lyme disease risk in an endemic region of Quebec, Canada.

BACKGROUND: Lyme disease (LD) and other tick-borne diseases are emerging across Canada. Spatial and temporal LD risk is typically estimated using acarological surveillance and reported human cases, the former not considering human behavior leading to tick exposure and the latter occurring after infection. OBJECTIVES: The primary objective was to explore, at the census subdivision level (CSD), the associations of self-reported tick exposure, alternative risk indicators (predicted tick density, eTick submissions, public health risk level), and ecological variables (Ixodes scapularis habitat suitability index and cumulative degree days > 0 °C) with incidence proportion of LD. A secondary objective was to explore which of these predictor variables were associated with self-reported tick exposure at the CSD level. METHODS: Self-reported tick exposure was measured in a cross-sectional populational health survey conducted in 2018, among 10,790 respondents living in 116 CSDs of the Estrie region, Quebec, Canada. The number of reported LD cases per CSD in 2018 was obtained from the public health department. Generalized linear mixed-effets models accounting for spatial autocorrelation were built to fulfill the objectives. RESULTS: Self-reported tick exposure ranged from 0.0 % to 61.5 % (median 8.9 %) and reported LD incidence rates ranged from 0 to 324 cases per 100,000 person-years, per CSD. A positive association was found between self-reported tick exposure and LD incidence proportion (ß = 0.08, CI = 0.04,0.11, p < 0.0001). The best-fit model included public health risk level (AIC: 144.2), followed by predicted tick density, ecological variables, self-reported tick exposure and eTick submissions (AIC: 158.4, 158.4, 160.4 and 170.1 respectively). Predicted tick density was the only significant predictor of self-reported tick exposure (ß = 0.83, CI = 0.16,1.50, p = 0.02). DISCUSSION: This proof-of-concept study explores self-reported tick exposure as a potential indicator of LD risk using populational survey data. This approach may offer a low-cost and simple tool for evaluating LD risk and deserves further evaluation.

Quality over quantity in active tick surveillance: Sentinel surveillance outperforms risk-based surveillance for tracking tick-borne disease emergence in southern Canada.

Background: Lyme disease (LD) emerged in southern Québec at the start of the century, with many municipalities now endemic. A coordinated active surveillance programme has been in place in the province of Québec since 2014, including a limited number of sentinel field sites resampled each year and a larger set of accessory field sites that change yearly according to the LD surveillance signal. We aimed to evaluate whether a sentinel approach to active surveillance was more representative of LD risk to human populations, compared to risk-based surveillance. Methods: We compared enzootic hazard measures (average nymph densities) from sentinel and accessory sites with LD risk (number of human LD cases) across the study area between 2015 and 2019 using local bivariate Moran's I analysis. Results: Hazard measures from sentinel sites captured spatial risk significantly better than data from accessory sites (χ2=20.473, p<0.001). In addition, sentinel sites successfully tracked the interannual trend in LD case numbers, whereas accessory sites showed no association despite the larger sample size. Conclusion: Where surveillance aims to document changes in tick-borne disease risk over time and space, we suggest that repeated sampling of carefully selected field sites may be most effective, while risk-based surveillance may be more usefully applied to confirm the presence of emerging disease risk in a specific region of interest or to identify suitable sites for long-term monitoring as LD and other tick-borne diseases continue to emerge.

Integrated human behavior and tick risk maps to prioritize Lyme disease interventions using a 'One Health' approach.

Lyme disease (LD) risk is emerging rapidly in Canada due to range expansion of its tick vectors, accelerated by climate change. The risk of contracting LD varies geographically due to variability in ecological characteristics that determine the hazard (the densities of infected host-seeking ticks) and vulnerability of the human population determined by their knowledge and adoption of preventive behaviors. Risk maps are commonly used to support public health decision-making on Lyme disease, but the ability of the human public to adopt preventive behaviors is rarely taken into account in their development, which represents a critical gap. The objective of this work was to improve LD risk mapping using an integrated social-behavioral and ecological approach to: (i) compute enhanced integrated risk maps for prioritization of interventions and (ii) develop a spatially-explicit assessment tool to examine the relative contribution of different risk factors. The study was carried out in the Estrie region located in southern Québec. The blacklegged tick, Ixodes scapularis, infected with the agent of LD is widespread in Estrie and as a result, regional LD incidence is the highest in the province. LD knowledge and behaviors in the population were measured in a cross-sectional health survey conducted in 2018 reaching 10,790 respondents in Estrie. These data were used to create an index for the social-behavioral component of risk in 2018. Local Empirical Bayes estimator technique were used to better quantify the spatial variance in the levels of adoption of LD preventive activities. For the ecological risk analysis, a tick abundance model was developed by integrating data from ongoing long-term tick surveillance programs from 2007 up to 2018. Social-behavioral and ecological components of the risk measures were combined to create vulnerability index maps and, with the addition of human population densities, prioritization index maps. Map predictions were validated by testing the association of high-risk areas with the current spatial distribution of human cases of LD and reported tick exposure. Our results demonstrated that social-behavioral and ecological components of LD risk have markedly different distributions within Estrie. The occurrence of human LD cases or reported tick exposure in a municipality was positively associated with tick density and the prioritization risk index (p < 0.001). This research is a second step towards a more comprehensive integrated LD risk assessment approach, examining social-behavioral risk factors that interact with ecological risk factors to influence the management of emerging tick-borne diseases, an approach that could be applied more widely to vector-borne and zoonotic diseases.

Current and future burden from Lyme disease in Québec as a result of climate change.

Context: Environmental changes will foster the spread of Ixodes scapularis ticks and increase the incidence of Lyme disease in Québec in the coming years. The objective of this study is to estimate the epidemiological and clinical burden and part of the current economic burden of Lyme disease in Québec and to estimate the number of cases expected by 2050. Methods: Cases of Lyme disease reported in Québec from 2015 to 2019 were used to describe their demographic, geographical and clinical characteristics and the cost of their initial care. Three incidence rate scenarios were then developed to estimate the number of cases expected by 2050, based on demographic and climate projections. Results: From 2016 to 2019, 1,473 cases of Lyme disease were reported in Québec. Over 90% of those cases were acquired in two regions of southern Québec (Estrie and Montérégie), while the individuals infected were residents from all over Québec. The average age of cases is 44 years and 66% of infections were at the localized stage, the first stage of Lyme disease. The cost of initial care is estimated at an average of $182 CAN per patient ($47 CAN at the localized stage and $443 CAN at the disseminated stage). According to projections, over 95% of the Québec population will live in a climate zone conducive to the establishment of ticks by 2050, with a number of cases acquired in Québec being 1.3 to 14.5 times higher than in 2019, depending on the incidence rate scenario used. Conclusion: The epidemiological burden is concentrated primarily in southern Québec, but the clinical and economic burden is already distributed throughout the province. The projections for 2050 should help the regions of Québec adapt and optimize public health protection measures.

Passive surveillance for I. scapularis ticks: enhanced analysis for early detection of emerging Lyme disease risk.

Lyme disease (LD) is emerging in Canada because of the northward expansion of the geographic range of the tick vector Ixodes scapularis (Say). Early detection of emerging areas of LD risk is critical to public health responses, but the methods to do so on a local scale are lacking. Passive tick surveillance has operated in Canada since 1990 but this method lacks specificity for identifying areas where tick populations are established because of dispersion of ticks from established LD risk areas by migratory birds. Using data from 70 field sites in Quebec visited previously, we developed a logistic regression model for estimating the risk of I. scapularis population establishment based on the number of ticks submitted in passive surveillance and a model-derived environmental suitability index. Sensitivity-specificity plots were used to select an optimal threshold value of the linear predictor from the model as the signal for tick population establishment. This value was used to produce an "Alert Map" identifying areas where the passive surveillance data suggested ticks were establishing in Quebec. Alert Map predictions were validated by field surveillance at 76 sites: the prevalence of established I. scapularis populations was significantly greater in areas predicted as high-risk by the Alert map (29 out of 48) than in areas predicted as moderate-risk (4 out of 30) (P < 0.001). This study suggests that Alert Maps created using this approach can provide a usefully rapid and accurate tool for early identification of emerging areas of LD risk at a geographic scale appropriate for local disease control and prevention activities.

Criteria for selecting sentinel unit locations in a surveillance system for vector-borne disease: A decision tool.

Objectives: With vector-borne diseases emerging across the globe, precipitated by climate change and other anthropogenic changes, it is critical for public health authorities to have well-designed surveillance strategies in place. Sentinel surveillance has been proposed as a cost-effective approach to surveillance in this context. However, spatial design of sentinel surveillance system has important impacts on surveillance outcomes, and careful selection of sentinel unit locations is therefore an essential component of planning. Methods: A review of the available literature, based on the realist approach, was used to identify key decision issues for sentinel surveillance planning. Outcomes of the review were used to develop a decision tool, which was subsequently validated by experts in the field. Results: The resulting decision tool provides a list of criteria which can be used to select sentinel unit locations. We illustrate its application using the case example of designing a national sentinel surveillance system for Lyme disease in Canada. Conclusions: The decision tool provides researchers and public health authorities with a systematic, evidence-based approach for planning the spatial design of sentinel surveillance systems, taking into account the aims of the surveillance system and disease and/or context-specific considerations.

Sentinel Surveillance Contributes to Tracking Lyme Disease Spatiotemporal Risk Trends in Southern Quebec, Canada.

Lyme disease (LD) is a tick-borne disease which has been emerging in temperate areas in North America, Europe, and Asia. In Quebec, Canada, the number of human LD cases is increasing rapidly and thus surveillance of LD risk is a public health priority. In this study, we aimed to evaluate the ability of active sentinel surveillance to track spatiotemporal trends in LD risk. Using drag flannel data from 2015-2019, we calculated density of nymphal ticks (DON), an index of enzootic hazard, across the study region (southern Quebec). A Poisson regression model was used to explore the association between the enzootic hazard and LD risk (annual number of human cases) at the municipal level. Predictions from models were able to track both spatial and interannual variation in risk. Furthermore, a risk map produced by using model predictions closely matched the official risk map published by provincial public health authorities, which requires the use of complex criteria-based risk assessment. Our study shows that active sentinel surveillance in Quebec provides a sustainable system to follow spatiotemporal trends in LD risk. Such a network can support public health authorities in informing the public about LD risk within their region or municipality and this method could be extended to support Lyme disease risk assessment at the national level in Canada.

Management and clinical outcomes of Lyme disease in acute care facilities in 2 endemic regions of Quebec, Canada: a multicentre retrospective cohort study.

BACKGROUND: Despite increases in cases of Lyme disease, little is known about the management and clinical course of the disease in Canada. We aimed to describe the management and clinical course of Lyme disease in patients treated in acute care facilities in Quebec and to assess adherence to the 2006 Infectious Diseases Society of America (IDSA) guideline. METHODS: This retrospective multicentre cohort study included pediatric and adult patients with serologically confirmed Lyme disease treated in acute care facilities (12 community hospitals and 2 tertiary care centres) of 2 endemic regions of Quebec (Estrie and Montérégie), from 2004 to 2017. We considered drug choice, prescribed dose and treatment duration in assessing adherence of prescriptions to the 2006 IDSA guideline. The main outcome was complete resolution of symptoms at 3 months after the initiation of treatment. RESULTS: We included 272 patients from 14 institutions (age range 3-87 yr). Early disseminated Lyme disease (140 patients [51%]) was predominant. Adherence to the IDSA guideline was observed in 235 (90%) of the 261 cases with complete information, and adherence was stable over time (2004-2013: 57/64 [89%]; 2014-2015: 64/71 [90%]; 2016-2017: 114/126 [90%]; p = 0.8). Non-adherence to the guideline (n = 26) was predominantly due to longer-than-recommended treatment duration (16/26 [62%]). Resolution of objective signs at 3 months after treatment initiation occurred in 265 (99%) of 267 patients, whereas post-treatment Lyme disease syndrome was observed in 27 patients (10%) with increasing incidence over time (2004-2013: 3/65 [5%]; 2014-2015: 4/73 [5%]; 2016-2017: 20/129 [16%]; p = 0.02). INTERPRETATION: We observed clinical resolution of Lyme disease in 99% of the patients, and most treatments (90%) complied with the 2006 IDSA guideline. The incidence of post-treatment Lyme disease syndrome increased over the study period, warranting further prospective studies.

An ecological approach to predict areas with established populations of Ixodes scapularis in Quebec, Canada.

Public health management of Lyme disease (LD) is a dynamic challenge in Canada. Climate warming is driving the northward expansion of suitable habitat for the tick vector, Ixodes scapularis. Information about tick population establishment is used to inform the risk of LD but is challenged by sampling biases from surveillance data. Misclassifying areas as having no established tick population underestimates the LD risk classification. We used a logistic regression model at the municipal level to predict the probability of I. scapularis population establishment based on passive tick surveillance data during the period of 2010-2017 in southern Quebec. We tested for the effect of abiotic and biotic factors hypothesized to influence tick biology and ecology. Additional variables controlled for sampling biases in the passive surveillance data. In our final selected model, tick population establishment was positively associated with annual cumulative degree-days > 0°C, precipitation and deer density, and negatively associated with coniferous and mixed forest types. Sampling biases from passive tick surveillance were controlled for using municipal population size and public health instructions on tick submissions. The model performed well as indicated by an area under the curve (AUC) of 0.92, sensitivity of 86% and specificity of 81%. Our model enables prediction of I. scapularis population establishment in areas which lack data from passive tick surveillance and may improve the sensitivity of LD risk categorization in these areas. A more sensitive system of LD risk classification is important for increasing awareness and use of protective measures employed against ticks, and decreasing the morbidity associated with LD.

Risk maps for range expansion of the Lyme disease vector, Ixodes scapularis, in Canada now and with climate change.

BACKGROUND: Lyme disease is the commonest vector-borne zoonosis in the temperate world, and an emerging infectious disease in Canada due to expansion of the geographic range of the tick vector Ixodes scapularis. Studies suggest that climate change will accelerate Lyme disease emergence by enhancing climatic suitability for I. scapularis. Risk maps will help to meet the public health challenge of Lyme disease by allowing targeting of surveillance and intervention activities. RESULTS: A risk map for possible Lyme endemicity was created using a simple risk algorithm for occurrence of I. scapularis populations. The algorithm was calculated for each census sub-division in central and eastern Canada from interpolated output of a temperature-driven simulation model of I. scapularis populations and an index of tick immigration. The latter was calculated from estimates of tick dispersion distances by migratory birds and recent knowledge of the current geographic range of endemic I. scapularis populations. The index of tick immigration closely predicted passive surveillance data on I. scapularis occurrence, and the risk algorithm was a significant predictor of the occurrence of I. scapularis populations in a prospective field study. Risk maps for I. scapularis occurrence in Canada under future projected climate (in the 2020s, 2050s and 2080s) were produced using temperature output from the Canadian Coupled Global Climate Model 2 with greenhouse gas emission scenario enforcing 'A2' of the Intergovernmental Panel on Climate Change. CONCLUSION: We have prepared risk maps for the occurrence of I. scapularis in eastern and central Canada under current and future projected climate. Validation of the risk maps provides some confidence that they provide a useful first step in predicting the occurrence of I. scapularis populations, and directing public health objectives in minimizing risk from Lyme disease. Further field studies are needed, however, to continue validation and refinement of the risk maps.

[Preventing nosocomial infections: a topic of concern in developing countries as well]. / Prévention des infections nosocomiales. Un sujet d'actualité aussi dans les pays en voie de développement.

This study was conducted in an hospital in the Democratic Republic of Congo. The project goals were to assess the effectiveness of a campaign to encourage hand washing, improve caregivers' knowledge of infection prevention, quantify their knowledge of the subject and determine why caregivers were not washing their hands. The data were collected by looking at 22 nurses using an observation grid, once before and once after the campaign. There was a highly significant increase of 36% (p = 0.003) in the practice of hand washing, rising from 9% in the first observation to 45% in the second. It was also observed that the practice significantly increased with the nurse/patient ratio (p = 0.04). The most experienced nurses were also the ones who practised hand washing the least, and for whom the difference between the two observation periods was smallest. The message for nurses here and elsewhere in the world is clear: better hand-washing practices are undeniably an effective and efficient measure, and should be applied systematically.

The changing landscape of travel health services in Canada.

Canadians are increasingly travelling to areas that would necessitate a pre-travel consultation. Changes in professional regulations in Canada allow greater autonomy of nurses and pharmacists, resulting in shifts in provision of travel health services. We surveyed 824 Canadian travel clinics, 270 (33%) of whom responded. Private clinics were most common, and more likely to offer extended hours and drop-in appointments. In one province, pharmacies dominated. Half the services were relatively new and a similar proportion saw fewer than 10 patients weekly; 1/3 had a single provider. The increased spectrum of services may increase convenience for travellers but the large proportion seeing low numbers of clients will challenge providers to maintain competence.