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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.

One Health surveillance for antimicrobial resistance has been promoted by the scientific community and by international organizations for more than a decade. In this article, we highlight issues that need to be addressed to improve the understanding of the effectiveness of One Health surveillance for antimicrobial resistance. We also outline the evidence needed to support countries planning to increase the level of integration of their surveillance system. Based on experience in Canada and other countries, we argue that more effort is needed to understand and measure the added value of One Health for antimicrobial resistance surveillance and to identify the most effective integration strategies. To date, guidelines for the development of One Health surveillance have focused mainly on the types of data that should be integrated. However, it may be necessary to apply the concept of One Health to surveillance tasks beyond data integration to realize the full value of the approach. Integration can be enhanced across different surveillance activities (data collection, analysis, interpretation and dissemination), taking account of the different skills and perspectives of experts and stakeholders involved. More research is needed to investigate the mechanisms through which a One Health approach to surveillance can increase the performance of antimicrobial resistance surveillance and, ultimately, improve health outcomes.Cela fait plus de dix ans que la communauté scientifique et les organisations internationales préconisent l'application de l'approche «Un monde, une santé» à la surveillance de la résistance aux antimicrobiens. Cet article souligne les éléments à considérer pour mieux comprendre l'efficacité d'une surveillance fondée sur cette approche. Nous y évoquons également les données requises pour éclairer les pays dans la définition de leurs plans nationaux afin d'améliorer le niveau d'intégration de leur système de surveillance. À partir de l’expérience du Canada et d'autres pays, nous estimons que des efforts doivent encore être faits pour comprendre et mesurer la véritable valeur ajoutée de l'approche «Un monde, une santé» dans le cadre de la surveillance de la résistance aux antimicrobiens et afin d'identifier les stratégies d'intégration les plus efficaces. À ce jour, les lignes directrices pour l'établissement d'une surveillance fondée sur cette approche se sont principalement axées sur les types de données qui devraient être intégrées. Néanmoins, pour exploiter toute la valeur de cette approche, il pourrait être utile d'appliquer le concept «Un monde, une santé» aux activités de surveillance au-delà de la simple intégration des données. Une meilleure intégration peut être obtenue au niveau des différentes activités de surveillance (collecte, analyse, interprétation et diffusion des données) en tenant compte des différentes compétences et des différents points de vue des experts et des parties prenantes. De nouvelles recherches sont nécessaires pour comprendre les mécanismes par lesquels l'approche «Un monde, une santé» appliquée à la surveillance peut améliorer les performances de la surveillance de la résistance aux antimicrobiens et, en fin de compte, améliorer les résultats de santé.La comunidad científica y las organizaciones internacionales han promovido durante más de una década la vigilancia sanitaria de la resistencia a los antimicrobianos. En este artículo, destacamos las cuestiones que deben abordarse para mejorar la comprensión de la eficacia de la vigilancia de la resistencia a los antimicrobianos de One Health. También esbozamos las pruebas necesarias para apoyar a los países que planean aumentar el nivel de integración de su sistema de vigilancia. Basándonos en la experiencia de Canadá y de otros países, sostenemos que se necesitan más esfuerzos para comprender y medir el valor agregado de One Health para la vigilancia de la resistencia a los antimicrobianos y para identificar las estrategias de integración más eficaces. Hasta la fecha, las directrices para el desarrollo de vigilancia de One Health se han centrado principalmente en los tipos de datos que deben integrarse. Sin embargo, puede ser necesario aplicar el concepto de One Health a tareas de vigilancia que van más allá de la integración de datos para aprovechar todo el valor del enfoque. La integración puede mejorarse en las diferentes actividades de vigilancia (recopilación, análisis, interpretación y difusión de datos), teniendo en cuenta las diferentes competencias y perspectivas de los expertos y las partes interesadas. Se necesita más investigación para estudiar los mecanismos mediante los cuales un enfoque de vigilancia de One Health puede aumentar el rendimiento de la vigilancia de la resistencia a los antimicrobianos y, en última instancia, mejorar los resultados sanitarios.تم الترويج لمراقبة One Health لمكافحة مضادات الميكروبات بواسطة المجتمع العلمي ومنظمات دولية منذ ما يزيد عن عقد من الزمان. نسلط في هذا المقال الضوء على القضايا التي بحاجة للتناول لتحسين فهم فعالية مراقبة One Health لمكافحة مضادات الميكروبات. كما نوضح الأدلة اللازمة لدعم الدول التي تخطط لزيادة مستوى التكامل في نظام المراقبة الخاص بها. وبناءً على التجربة الكندية وتجارب بلدان أخرى، فإننا نزعم أننا بحاجة إلى بذل المزيد من الجهد لفهم وقياس القيمة المضافة لنظام One Health لمراقبة مكافحة مضادات الميكروبات، ولتحديد أكثر استراتيجيات التكامل من حيث الفعالية. وحتى الآن، ركزت إرشادات تطوير نظام One Health للمراقبة بشكل أساسي على أنواع البيانات التي ينبغي إحداث التكامل فيما بينها. ومع ذلك، قد يكون من الضروري تطبيق مفهوم One Health على مهام المراقبة التي تتجاوز تكامل البيانات، وذلك لإدراك القيمة الكاملة لهذا النهج. يمكن تعزيز التكامل عبر أنشطة المراقبة المختلفة (جمع البيانات وتحليلها وتفسيرها ونشرها)، مع الأخذ في الاعتبار المهارات المختلفة ووجهات نظر الخبراء وأصحاب المصلحة المعنيين. هناك حاجة إلى مزيد من الأبحاث للتحقيق في الآليات التي يمكن من خلالها لنهج One Health للمراقبة أن يزيد من أداء مراقبة مكافحة مضادات الميكروبات، مما يؤدي في النهاية إلى تحسين النتائج الصحية.十多年来，科学界和国际组织一直致力于对抗菌素耐药性进行“唯一健康”监测。在本文中，我们强调了需要解决的问题，旨在提高“唯一健康”监测对抗菌素耐药性有效性的认识。我们还对所需的证据进行了概述，以支持那些计划提高其监测系统整合水平的国家。根据加拿大及他国经验，我们认为需要付出更多努力来理解和衡量“唯一健康”监测对抗菌素耐药性的附加价值，并确定最有效的整合策略。迄今为止，制定“唯一健康”监测的指南主要侧重于应整合的数据类型。然而，可能有必要将“唯一健康”概念应用于数据整合之外的监测任务，以实现该方法的全部价值。可以通过不同的监测活动（数据收集、分析、解释和传播）加强整合，同时考虑到所涉专家和利益相关者的不同技能和观点。需进一步研究以调查提高抗菌素耐药性监测表现的“唯一健康”方法，并最终改善健康结果。.Система надзора за резистентностью к антимикробным препаратам One Health находит поддержку научного сообщества и международных организаций уже в течение более десяти лет. В этой статье освещаются проблемы, которые следует решить для улучшения понимания эффективности надзора за резистентностью к антимикробным препаратам One Health. Авторы также описывают характер подтверждений, необходимых для поддержки стран, планирующих повысить уровень интеграции своих надзорных систем. На основании опыта Канады и других стран оспаривается утверждение о том, что нужно больше усилий для понимания и измерения ценности системы надзора за резистентностью к антимикробным препаратам One Health и для выявления наиболее эффективных стратегий интеграции. На сегодня рекомендации по разработке системы надзора One Health в основном сосредотачивались на типах данных, которые следует интегрировать. Однако, чтобы оценить всю ценность подхода, может понадобиться применение концепции One Health к надзорным задачам, не ограничивающимся интеграцией данных. Интеграция может быть усилена между разного рода надзорной деятельностью (сбор данных, анализ, интерпретация и распространение) с учетом различия в навыках и точках зрения специалистов и партнеров, участвующих в работе системы. Требуются дополнительные исследования для изучения механизмов, посредством которых подход One Health к вопросам надзора может улучшить качество работы систем надзора за антимикробной резистентностью и, в конце концов, улучшить результаты работы системы здравоохранения.

Dogs have been an integral part of the Inuit social and cultural environment for generations, but their presence also generates public health risks such as bites and exposure to zoonotic diseases such as rabies. In Nunavik, Canada, some prevention and control interventions targeting dogs have been implemented but have not demonstrated their effectiveness in a long-term sustainable perspective. This study was conducted in one Inuit community of Nunavik and used mixed methods to get a better understanding of factors that affect human and dog health, dog-related risks for humans and perceptions of dogs in Inuit communities using an interdisciplinary perspective in line with the Ecohealth approach. Results unveiled different perceptions and practices between Inuit and non-Inuit members of the community with regard to dogs and highlighted the positive role of dogs and their importance for Inuit health and well-being. This study provides new knowledge that is crucial for the development of integrated, sustainable and culturally adapted solutions to both the mitigation of dog-related health risks and the reinforcement of health and wellness benefits of dogs for Inuit.

International audience; Adjusting to global climate and socio-environmental changes has become a major issue for many societies, especially in the Arctic. Many Inuit wish to better understand the changes taking place. In 2013, an international Observatory of Human–Environment Interactions (OHMi) was established in Nunavik to identify these changes, study their cumulative impact on the socio-ecosystem and to help develop adaptation measures to improve the well-being of Inuit communities. To this end, a team of academics and local Inuit partners joined forces to develop an integrated, interdisciplinary, collaborative research program. Using a participatory action research (PAR) approach, the OHMi Nunavik set the following research priorities: elder-youth knowledge transmission, northern agriculture, preservation of Inuit culture, language and identity, protected areas, mining employment, natural hazards and risks, and wildlife vulnerability. By strengthening the collaborations between multidisciplinary Canadian and French research teams, the OHMi Nunavik program integrates local and scientific knowledge both in planning the research and in disseminating the results; L’adaptation aux changements climatiques et socio-environnementaux est devenue un enjeu majeur pour de nombreuses sociétés, notamment dans l’Arctique. De nombreux Inuit souhaitent mieux comprendre les changements qui se produisent. En 2013, un Observatoire international sur les interactions Homme-Milieu (OHMi) a été mis en place au Nunavik pour identifier ces changements, étudier leur impact cumulatif sur le socio-écosystème et pour aider à élaborer des mesures d’adaptation afin d’améliorer le bien-être des communautés inuit. À cette fin, une équipe d’universitaires et de partenaires Inuit locaux ont uni leurs forces pour développer un programme de recherche concerté, intégré et interdisciplinaire. En utilisant une approche de recherche-action participative, l’OHMi Nunavik a défini les priorités de recherche suivantes: transmission des connaissances entre les aînés et les jeunes, agriculture nordique, préservation de la culture, de la langue et de l’identité inuit, aires protégées, emplois dans les mines, risques naturels et vulnérabilité de la faune. En renforçant les collaborations entre les équipes de recherche multidisciplinaires canadiennes et françaises, le programme de l’OHMi Nunavik intègre les connaissances locales et scientifiques dans la planification de la recherche et la diffusion des résultats

Prioritizing resources for optimal responses to an ever growing list of existing and emerging infectious diseases represents an important challenge to public health. In the context of climate change, there is increasing anticipated variability in the occurrence of infectious diseases, notably climate-sensitive vector-borne diseases. An essential step in prioritizing efforts is to identify what considerations and concerns to take into account to guide decisions and thus set disease priorities. This study was designed to perform a comprehensive review of criteria for vector-borne disease prioritization, assess their applicability in a context of climate change with a diverse cross-section of stakeholders in order to produce a baseline list of considerations to use in this decision-making context. Differences in stakeholder choices were examined with regards to prioritization of these criteria for research, surveillance and disease prevention and control objectives. A preliminary list of criteria was identified following a review of the literature. Discussions with stakeholders were held to consolidate and validate this list of criteria and examine their effects on disease prioritization. After this validation phase, a total of 21 criteria were retained. A pilot vector-borne disease prioritization exercise was conducted using PROMETHEE to examine the effects of the retained criteria on prioritization in different intervention domains. Overall, concerns expressed by stakeholders for prioritization were well aligned with categories of criteria identified in previous prioritization studies. Weighting by category was consistent between stakeholders overall, though some significant differences were found between public health and non-public health stakeholders. From this exercise, a general model for climate-sensitive vector-borne disease prioritization has been developed that can be used as a starting point for further public health prioritization exercises relating to research, surveillance, and prevention and control interventions in a context of climate change. Multi-stakeholder engagement in prioritization can help broaden the range of criteria taken into account, offer opportunities for early identification of potential challenges and may facilitate acceptability of any resulting decisions.

SUMMARYCampylobacteriosis, the most frequent bacterial enteric disease, shows a clear yet unexplained seasonality. The study purpose was to explore the influence of seasonal fluctuation in the contamination of and in the behaviour exposures to two important sources ofCampylobacteron the seasonality of campylobacteriosis. Time series analyses were applied to data collected through an integrated surveillance system in Canada in 2005–2010. Data included sporadic, domestically-acquired cases ofCampylobacter jejuniinfection, contamination of retail chicken meat and of surface water byC. jejuni, and exposure to each source through barbequing and swimming in natural waters. Seasonal patterns were evident for all variables with a peak in summer for human cases and for both exposures, in fall for chicken meat contamination, and in late fall for water contamination. Time series analyses showed that the observed campylobacteriosis summer peak could only be significantly linked to behaviour exposures rather than sources contamination (swimming rather than water contamination and barbequing rather than chicken meat contamination). The results indicate that the observed summer increase in human cases may be more the result of amplification through more frequent risky exposures rather than the result of an increase of theCampylobactersource contamination.

The effects of climate change on infectious diseases are an important global health concern and necessitate decisions for allocation of resources. Economic tools have been used previously; however, how prioritization results might differ when done using broader considerations identified by local stakeholders has yet to be assessed. A multicriteria decision analysis (MCDA) approach was used to assess multi-stakeholder expressed concerns around disease prioritization via focus groups held in Quebec and Burkina Faso. Stakeholders weighted criteria and comparisons were made across study sites. A pilot disease prioritization was done to examine effects on disease rankings. A majority of identified criteria were common to both sites. The effect of context specific criteria and weights resulted in similar yet distinct prioritizations of diseases. The presence of consistent criteria between sites suggests that common concerns exist for prioritization; however, context-specific adjustments reveal much regarding resource availability, capacity and concerns that should be considered as this impacts disease ranking. Participatory decision aid approaches facilitate rich knowledge exchange and problem structuring. Furthermore, given multiple actors in low- and middle-income countries settings, multi-actor collaborations across non-governmental organizations, local government and community are important. Formal mechanisms such as MCDA provide means to foster consensus, shared awareness and collaboration.

Designing preventive programs relevant to vector-borne diseases such as Lyme disease (LD) can be complex given the need to include multiple issues and perspectives into prioritizing public health actions. A multi-criteria decision aid (MCDA) model was previously used to rank interventions for LD prevention in Quebec, Canada, where the disease is emerging. The aim of the current study was to adapt and evaluate the decision model constructed in Quebec under a different epidemiological context, in Switzerland, where LD has been endemic for the last thirty years. The model adaptation was undertaken with a group of Swiss stakeholders using a participatory approach. The PROMETHEE method was used for multi-criteria analysis. Key elements and results of the MCDA model are described and contrasted with the Quebec model. All criteria and most interventions of the MCDA model developed for LD prevention in Quebec were directly transferable to the Swiss context. Four new decision criteria were added, and the list of proposed interventions was modified. Based on the overall group ranking, interventions targeting human populations were prioritized in the Swiss model, with the top ranked action being the implementation of a large communication campaign. The addition of criteria did not significantly alter the intervention rankings, but increased the capacity of the model to discriminate between highest and lowest ranked interventions. The current study suggests that beyond the specificity of the MCDA models developed for Quebec and Switzerland, their general structure captures the fundamental and common issues that characterize the complexity of vector-borne disease prevention. These results should encourage public health organizations to adapt, use and share MCDA models as an effective and functional approach to enable the integration of multiple perspectives and considerations in the prevention and control of complex public health issues such as Lyme disease or other vector-borne and zoonotic diseases.

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.

Background Although Campylobacter is the leading cause of reported bacterial gastro-enteritis in industrialized countries, little is known on its recurrence. The objective of this study is to describe the risk and the patient characteristics of recurrent episodes of human campylobacteriosis reported in Quebec. Methods Laboratory-confirmed cases of campylobacteriosis reported in the province of Quebec, Canada, through ongoing surveillance between 1996 and 2006 were analyzed. The risk of having a recurrent episode of campylobacteriosis was described using life table estimates. Logistic regression was used to assess if gender, age and patient residential location were associated with an increased risk of recurrence. Results Compared to the baseline risk, the risk for a recurrent disease event was higher for a period of four years and followed a decreasing trend. This increased risk of a recurrent event was similar across gender, but higher for people from rural areas and lower for children under four years of age. Conclusions These results may suggest the absence of durable immunity or clinical resilience following a first episode of campylobacteriosis and periodical re-exposure, at least among cases reported through the surveillance system.

OBJECTIVE:To describe rates of antimicrobial resistance (AMR) amongSalmonellaandShigellaisolates reported in five Canadian provinces, focusing on clinically important antimicrobials.METHODS:The authors retrospectively investigated AMR rates among 6219Salmonellaand 1673Shigellaisolates submitted to provincial public health laboratories in Alberta, Newfoundland and Labrador, Ontario, Prince Edward Island and Saskatchewan from 1997 to 2000; these isolates were estimated to represent 41% ofSalmonellacases and 72% ofShigellacases reported by the study provinces.RESULTS:AmongSalmonellaisolates, 27% (1704 of 6215) were resistant to ampicillin, 2.2% (135 of 6122) to trimethoprim/sulfamethoxazole, 1.5% (14 of 938) to nalidixic acid, 1.2% (one of 84) to lomafloxacin and 0.08% (five of 6163) to ciprofloxacin. AmongShigellaisolates, 70% (1144 of 1643) were resistant to trimethoprim/sulfamethoxazole, 65% (1079 of 1672) to ampicillin, 3.1% (eight of 262) to nalidixic acid, 0.49% (eight of 1636) to ciprofloxacin, 0.14% (one of 700) to ceftriaxone and 0.08% (one of 1292) to ceftazidime.CONCLUSIONS:Higher rates of resistance to clinically important antimicrobials (including ciprofloxacin) were observed among bothSalmonellaandShigellaisolates than has previously been reported. Current Canadian data on rates of AMR for these pathogens are required.

In spatial epidemiology, the choice of an appropriate geographical unit of analysis is a key decision that will influence most aspects of the study. In this study, we proposed and applied a set of measurable criteria applicable for orienting the choice of geographical unit. Nine criteria were selected, covering many aspects such as biological relevance, communicability of results, ease of data access, distribution of exposure variables, cases and population, and shape of unit. These criteria were then applied to compare various geographical units derived from administrative, health services, and natural frameworks that could be used for the study of the spatial distribution of campylobacteriosis in the province of Quebec, Canada. In this study, municipality was the geographical unit that performed the best according to our assessment and given the specific objectives and time period of the study. Future research areas for optimizing the choice of geographical unit are discussed.

Background Campylobacter is a common cause of bacterial gastro-enteritis characterized by multiple environmental sources and transmission pathways. Ecological studies can be used to reveal important regional characteristics linked to campylobacteriosis risk, but their results can be influenced by the choice of geographical units of analysis. This study was undertaken to compare the associations between the incidence of campylobacteriosis in Quebec, Canada and various environmental characteristics using seven different sets of geographical units. Methods For each set of geographical unit, a conditional autoregressive model was used to model the incidence of reported cases of campylobacteriosis according to environmental (poultry density, ruminant density, slaughterhouse presence, temperature, and precipitation) and demographic (population density, level of education) characteristics. Models were compared in terms of number of significant predictors, differences in direction and magnitude of predictors, and fit of the models. Results In general, the number of significant predictors was reduced as the aggregation level increased. More aggregated scales tend to show larger but less precise estimates for all variables, with the exception of slaughterhouse presence. Regional characteristics associated with an increased regional risk of campylobacteriosis, for at least some geographical units, were high ruminant density, high poultry density, high population density, and presence of a large poultry slaughterhouse, whereas a reduction in risk was associated with a lower percentage of people with diplomas, a lower level of precipitation, and warmer temperature. Two clusters of elevated residual risk were observed, with different location and size depending on the geographical unit used. Conclusions Overall, our results suggest that the use of municipality or census consolidated subdivision were the most optimal scales for studying environmental determinants of campylobacteriosis at a regional level. This study highlights the need for careful selection and analysis of geographical units when using ecological study designs.

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. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-1539-2) contains supplementary material, which is available to authorized users.