Exposure and preventive behaviours toward ticks and Lyme disease in Canada: Results from a first national survey

Behavioral and cognitive factors influencing tick-borne disease risk in northeast China: Implications for prevention and control strategies

The growth in ecotourism and nature-based recreational activities in China has resulted in an increased frequency of visits to green spaces, thereby elevating exposure to ticks and the subsequent risk of tick-borne diseases. This study comprehensively investigate individual behavioral and cognitive factors associated with the risk of contracting tick-borne diseases to facilitate the development of effective prevention and control strategies, supporting public health initiatives in high-prevalence regions. We conducted an extensive questionnaire survey among 3000 residents from three northeastern provinces in China (Heilongjiang, Jilin, and Liaoning), where tick-borne diseases exhibit relatively high prevalence. The survey focused on gathering information regarding participants' tick bite history, perception of tick-borne disease risks, and outdoor activity patterns. Using structural equations analysis, we explored the pathways and strengths of the associations between these factors. Our findings revealed an average self-reported tick bite rate of 14% among the participants. Notably, tick-borne encephalitis exhibited the highest self-reported prevalence of infection (4%) among tick-borne diseases, while both Lyme disease and Severe fever with thrombocytopenia syndrome had a prevalence of 2%. The average rate of tick bites among respondents' pets was 14%, with bites predominantly located on the ears, back, and abdomen. The strongest correlation was observed between tick bite rate and subsequent infections, emphasizing its role as the primary contributing factors to infectious status. Moreover, our results indicated that the causal structure of tick-borne disease infections varied across different cities, underscoring the significance of considering the ecological environment and regional knowledge on ticks. This study provides valuable insights into the current landscape of tick-borne disease infections in northeast China and identifies potential behavioral and cognitive factors, an aspect that has not been previously investigated. Our findings enable predictions on the future impact of knowledge dissemination efforts and improved urban facilities on mitigating tick bites and reducing tick-borne disease infections.

Attitudes towards zoonotic disease risk vary across sociodemographic, communication and health-related factors: A general population survey on literacy about zoonoses in the Netherlands

Introduction

Literacy about zoonoses can contribute people adapt their behaviour to minimize zoonotic risks. In this study, associations between sociodemographic factors and zoonotic risk-averse attitudes were explored.

Objective

To determine factors significantly associated with literacy about zoonoses across sociodemographic groups to inform targeted interventions aiming at improving awareness and zoonotic risk-avoidance behaviours.

Method

Data was collected in 2022 using an online survey of a nationally representative sample of residents in the Netherlands. A multivariable logistic regression analysis, accounting for multiple hypothesis testing, was applied to assess whether there were significant associations between socio-demographic factors and attitudes towards zoonosis prevention.

Results

A total of 2039 respondents completed the survey. People who were female, older, highly educated and those who searched for information about zoonoses, were relatively more likely to report behaviours favourable to the prevention of zoonoses. However, people with limited language and computer skills and immunocompromised people were significantly more likely to report risky behaviours. There were no significant associations found for pregnant women, dog and cat owners, those with an intermediate level of education and those who do have contact with farm animals.

Conclusion

Certain sociodemographic groups display significantly riskier attitudes towards zoonoses. These groups provide targets where to improve literacy about zoonoses. This also implies that there is room for improvement in literacy about zoonoses, particularly among immunocompromised people and people with limited language and limited computer skills.

Epidemiologic and tick exposure characteristics among people with reported Lyme disease - Minnesota, 2011-2019

AIMS AND METHODS

In the United States, blacklegged Ixodes spp. ticks are the primary vector of Lyme disease. Minnesota is among the states with the highest reported incidence of Lyme disease, having an average of 1857 cases reported annually during 2011-2019. In contrast to the Northeast and mid-Atlantic United States where exposure to ticks predominately occurs around the home, the circumstances regarding risk for exposure to blacklegged ticks in Minnesota are not well understood, and risk is thought to be highest in rural areas where people often participate in recreational activities (e.g. hiking, visiting cabins). We analysed enhanced surveillance data collected by the Minnesota Department of Health during 2011-2019 to describe epidemiologic and tick exposure characteristics among people with reported Lyme disease.

RESULTS

We found that younger age, male gender, residence in a county with lower Lyme disease risk, residence in the Minneapolis-St. Paul metropolitan area, and an illness onset date later in the year were independently associated with higher odds of reporting tick exposures away from the home. We also describe the range of activities associated with tick exposure away from the home, including both recreational and occupational activities.

CONCLUSIONS

These findings refine our understanding of Lyme disease risk in Minnesota and highlight the need for heterogeneous public health prevention messaging, including an increased focus on peridomestic prevention measures among older individuals living in high-risk rural areas and recreational and occupational prevention measures among younger individuals living in the Minneapolis-St. Paul metropolitan area.

The risk of contact between visitors and Borrelia burgdorferi-infected ticks is associated with fine-scale landscape features in a southeastern Canadian nature park

BACKGROUND

Infectious diseases are emerging across temperate regions of the world, and, for some, links have been made between landscapes and emergence dynamics. For tick-borne diseases, public parks may be important exposure sites for people living in urbanized areas of North America and Europe. In most cases, we know more about the ecological processes that determine the hazard posed by ticks as disease vectors than we do about how human population exposure varies in urban natural parks.

METHODS

In this study, infrared counters were used to monitor visitor use of a public natural park in southern Quebec, Canada. A risk index representing the probability of encounters between humans and infected vectors was constructed. This was done by combining the intensity of visitor trail use and the density of infected nymphs obtained from field surveillance. Patterns of risk were examined using spatial cluster analysis. Digital forest data and park infrastructure data were then integrated using spatially explicit models to test whether encounter risk levels and its components vary with forest fragmentation indicators and proximity to park infrastructure.

RESULTS

Results suggest that, even at a very fine scales, certain landscape features and infrastructure can be predictors of risk levels. Both visitors and Borrelia burgdorferi-infected ticks concentrated in areas where forest cover was dominant, so there was a positive association between forest cover and the risk index. However, there were no associations between indicators of forest fragmentation and risk levels. Some high-risk clusters contributed disproportionately to the risk distribution in the park relative to their size. There were also two high-risk periods, one in early summer coinciding with peak nymphal activity, and one in early fall when park visitation was highest.

CONCLUSIONS

Here, we demonstrate the importance of integrating indicators of human behaviour visitation with tick distribution data to characterize risk patterns for tick-borne diseases in public natural areas. Indeed, understanding the environmental determinants of human-tick interactions will allow organisations to deploy more effective risk reduction interventions targeted at key locations and times, and improve the management of public health risks associated with tick-borne diseases in public spaces.

Knowledge, protective behaviours, and perception of Lyme disease in an area of emerging risk: results from a cross-sectional survey of adults in Ottawa, Ontario

BACKGROUND

The number of Lyme disease risk areas in Canada is growing. In regions with emerging tick populations, it is important to emphasize peridomestic risk and the importance of protective behaviours in local public health communication. This study aims to identify characteristics associated with high levels of Lyme disease knowledge and adoption of protective behaviours among residents in the Ottawa, Ontario region.

METHODS

A geographically stratified web survey was conducted in November 2020 (n = 2018) to determine knowledge, attitudes, and practices regarding Lyme disease among adult residents. Responses were used to calculate: (i) composite scores for knowledge and adoption of protective practices; and (ii) an exposure risk index based on reported activity in woodlands during the spring-to-fall tick exposure risk period.

RESULTS

60% of respondents had a high knowledge of Lyme disease, yet only 14% indicated they often use five or more measures to protect themselves. Factors strongly associated with a high level of Lyme disease knowledge included being 55 or older (Odds Ratio (OR) = 2.04), living on a property with a yard (OR = 3.22), having a high exposure index (OR = 1.59), and knowing someone previously infected with Lyme disease (OR = 2.05). Strong associations with the adoption of a high number of protective behaviours were observed with membership in a non-Indigenous racialized group (OR = 1.70), living on a property with a yard (OR = 2.37), previous infection with Lyme disease (OR = 2.13), prior tick bite exposure (OR = 1.62), and primarily occupational activity in wooded areas (OR = 2.31).

CONCLUSIONS

This study highlights the dynamics between Lyme disease knowledge, patterns of exposure risk awareness, and vigilance of personal protection in a Canadian region with emerging Lyme disease risk. Notably, this study identified gaps between perceived local risk and protective behaviours, presenting opportunities for targeted enhanced communication efforts in areas of Lyme disease emergence.

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.

Epidemiology and clinical manifestations of reported Lyme disease cases: Data from the Canadian Lyme disease enhanced surveillance system

Lyme disease cases reported in seven Canadian provinces from 2009 to 2019 through the Lyme Disease Enhanced Surveillance System are described herein by demographic, geography, time and season. The proportion of males was greater than females. Bimodal peaks in incidence were observed in children and older adults (≥60 years of age) for all clinical signs except cardiac manifestations, which were more evenly distributed across age groups. Proportions of disease stages varied between provinces: Atlantic provinces reported mainly early Lyme disease, while Ontario reported equal proportions of early and late-stage Lyme disease. Early Lyme disease cases were mainly reported between May through November, whereas late Lyme disease were reported in December through April. Increased awareness over time may have contributed to a decrease in the proportion of cases reporting late disseminated Lyme disease. These analyses help better describe clinical features of reported Lyme disease cases in Canada.

Tick bite risk factors and prevention measures in an area with emerging Powassan virus disease

Background

In the United States (U.S.), Powassan virus is primarily transmitted to humans by the black-legged tick (Ixodes scapularis). Rarely, infections can present as severe neuroinvasive disease. In 2019, four neuroinvasive disease cases were reported in Sussex County, New Jersey, U.S. We administered a survey to county residents to better understand tick bite risk factors and the performance of personal prevention measures.

Methods

A survey was administered in October 2019 to adult residents of randomly selected households. Questions focused on tick bite prevention and risk factors. Crude and adjusted odds ratios (ORs) and 95% confidence intervals were calculated for various outcomes.

Results

Of 274 participants, 25% were previously diagnosed with a tick-borne disease, and 42% reported finding an attached tick in 2019. Yardwork and gardening (OR = 7.38) and spending >50 hours outdoors per week (OR = 8.15) were associated with finding an attached tick. Finding an attached tick was inversely associated with the number of prevention measures used, indicating that a layered approach could reduce the risk of tick bites. Those who performed post-outdoor activity prevention measures (e.g., tick checks) were less likely to have a tick attached compared to finding a crawling tick.

Conclusion

Compliance with prevention recommendations was low, despite a high prevalence of reported tick bites and significant outdoor exposures. Older adults and persons who spend significant time outdoors or engage in yardwork or gardening were at the highest risk of tick bites. Additional research is needed to further understand the barriers to tick bite prevention.

Describing the experience of livestock producers from Ohio, USA with ticks and associated diseases

BACKGROUND

As tick ranges expand across North America, the risk of tick bites and tick-borne diseases (TBDs, i.e. diseases or syndromes associated with ticks) rises for humans and animals, making prevention critical. Several U.S. studies have examined knowledge, attitudes, and practices regarding ticks and TBDs for various cohorts of people. However, among occupational groups with high exposure risk from ticks and TBDs are livestock producers, of which we know little about. To help address this gap, an electronic questionnaire was distributed to livestock producers in Ohio, U.S, a state with a robust agricultural sector.

METHODS

We generated descriptive statistics and conducted a multiple correspondence analysis followed by hierarchical clustering on principal components to identify producers with similar response profiles.

RESULTS

Responses from 57 producers showed that most (52.6%) think the American dog tick (Dermacentor variabilis) is found in Ohio but are unsure about other species. Although several TBDs are present in Ohio, most (> 50%) producers were unsure or unaware of their presence. Interestingly, most (54.4%) thought ticks pose major health risks for their livestock but fewer (49.1%) thought the same for humans. Regardless, most producers did employ at least one prevention method for themselves (96.5%) and their animals (82.5%). Cluster analysis (n = 48) identified three groups: the largest (n = 21) was considered "aware and cautious" consisting primarily of farm owners. The others generally practiced less prevention and consisted primarily of farm employees.

CONCLUSIONS

Our findings indicate that producers in Ohio practice prevention for themselves and their livestock, but demonstrate gaps in knowledge (e.g., TBD occurrence) and attitudes (e.g., health risks) that could be addressed via educational formats we found producers preferred (e.g., extension materials), to encourage informed prevention. This is especially important for farm employees that may practice less prevention because of lower awareness. Our study can guide others in regions faced with similar tick and TBD risks to protect occupational and livestock health.

Risk factors for Lyme disease resulting from residential exposure amidst emerging Ixodes scapularis populations: A neighbourhood-level analysis of Ottawa, Ontario

Lyme disease is an emerging health threat in Canada due to the continued northward expansion of the main tick vector, Ixodes scapularis. It is of particular concern to populations living in expanding peri-urban areas where residential development and municipal climate change response impact neighbourhood structure and composition. The objective of this study was to estimate associations of socio-ecological characteristics with residential Lyme disease risk at the neighbourhood scale. We used Lyme disease case data for 2017-2020 reported for Ottawa, Ontario to determine where patients' residential property, or elsewhere within their neighbourhood, was the suspected site of tick exposure. Cases meeting this exposure definition (n = 118) were aggregated and linked to neighbourhood boundaries. We calculated landscape characteristics from composited and classified August 2018 PlanetScope satellite imagery. Negative binomial generalized linear models guided by a priori hypothesized relationships explored the association between hypothesized interactions of landscape structure and the outcome. Increases in median household income, the number of forest patches, the proportion of forested area, forest edge density, and mean forest patch size were associated with higher residential Lyme disease incidence at the neighbourhood scale, while increases in forest shape complexity and average distance to forest edge were associated with reduced incidence (P<0.001). Among Ottawa neighbourhoods, the combined effect of forest shape complexity and average forest patch size was associated with higher residential Lyme disease incidence (P<0.001). These findings suggest that Lyme disease risk in residential settings is associated with urban design elements. This is particularly relevant in urban centres where local ecological changes may impact the presence of emerging tick populations and how residents interact with tick habitat. Further research into the mechanistic underpinnings of these associations would be an asset to both urban development planning and public health management.

Knowledge, attitudes, and practices for tick bite prevention and tick control among residents of Long Island, New York, USA

In the United States, tick-borne diseases (TBDs) are a major public health concern and a source of significant morbidity. To reduce tick-borne disease incidence, understanding factors associated with increased risk in humans for tick bites is necessary. These risk factors can include TBD knowledge, attitudes about prevention and care, and associated practices of individuals and their communities, including paying for preventive services. Our study focused on Long Island, New York, a region with high endemicity of ticks and TBDs. The purpose of our study was to identify gaps in the knowledge, attitudes, and practices regarding TBDs in residents of this region to inform priorities for TBD interventions. To this end, we performed a knowledge, attitudes, and practices (KAP) survey and collected 803 responses from Long Island residents. Our survey results demonstrated that Long Island residents had a low to moderate level of knowledge regarding ticks and TBDs. Still, residents expressed concern regarding TBDs, with increased levels of concern associated with increased likelihood of paying for tick control and for practicing tick bite prevention strategies. Individuals with pets were more likely to practice these tick bite prevention strategies. Residents with more frequent exposure to ticks, with a history of TBD in their household, and with higher general concern over ticks were also more likely to pay for tick control services. These findings highlight gaps in resident knowledge, differences in attitudes towards tick preventative behavior, and potential factors affecting motivation towards implementing tick control measures, which can inform future public health messaging regarding tick bite prevention.

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.

Perceived vulnerability for Lyme disease questionnaire: A social science tool for understanding tick-borne disease attitudes

Lyme disease has emerged as a growing epidemic across the U.S., with tick populations spreading north because of a plethora of human-induced factors. As the scope of this problem grows, there is a need to understand how vulnerable the public perceives themselves to be and how perceived vulnerability as a psychological construct influences public behavior. A growing body of literature has explored individual risk perceptions and individual preventative behaviors toward Lyme disease, but there remains a notable research gap regarding the concept of vulnerability. This empirical study establishes the first questionnaire for perceived vulnerability towards Lyme disease, modified from pre-existing infectious disease literature. This novel instrument was tested and compared with individual factors relating to preventative behaviors and source credibility of major information sources about Lyme disease in the state of Maine. Recent increases in black-legged tick (Ixodes scapularis) populations have affected the state of Maine in dramatic ways. This research specifically surveyed homeowners to explore their perceived vulnerability, source credibility, and individual protective intentions related to ticks and Lyme disease in Maine. Results from this study validate a modified perceived vulnerability scale for Lyme disease and highlight how understanding the relationships between these perceptions of vulnerability, individual behaviors, and sources of information can improve outreach and communication efforts about tick-borne diseases.

Rurality, Socioeconomic Status, and Residence in Environmental Risk Areas Associated with Increased Lyme Disease Incidence in Ontario, Canada: A Case-Control Study

Background: Lyme disease (LD) is the most common tick-borne illness in North America. LD is acquired through exposure to the tick vector, Ixodes scapularis, known as the blacklegged tick. In Canada, LD is rapidly emerging, with the establishment of I. scapularis in many newly endemic regions posing a growing risk to local communities. In the Canadian context, many environmental and socioeconomic risk factors for human LD infection are yet to be ascertained and the degree of risk associated with residential and community exposure to ticks is not well known. Methods: We conducted a matched case-control study in southeastern Ontario, using LD patient data from provincial laboratory databases and uninfected population controls from 2014 to 2018. We aimed to identify area-level risk factors for LD and associations with residence in environmental risk areas, defined as areas with high model-predicted probability of I. scapularis occurrence, using the neighborhood dissemination area as the unit of analysis. Results: Using multivariable conditional logistic regression analysis, we identified that patients with LD had higher odds (odds ratio, OR; 95% confidence interval, CI) of living in neighborhoods with high probability of tick occurrence in the environment (OR = 2.2; 95% CI: 2.0-2.5), low walkability (OR = 1.6; 95% CI: 1.2-2.1), low material deprivation (OR = 1.4; 95% CI: 1.2-1.7), and low ethnic concentration (OR = 8.1; 95% CI: 6.7-9.9). We also found that the odds of LD infection for individuals residing in environmental risk areas was highest for those living in public health units (PHUs) with <250,000 population (OR = 3.0; 95% CI: 2.4-3.9) compared to those living in PHUs with >1,000,000 population (OR = 1.5; 95% CI: 1.1-2.1). Conclusion: This study shows that odds of human LD infection in Ontario, Canada is higher in less urbanized areas with higher socioeconomic status and indicates that exposure to ticks around the home residence or neighborhood is linked to increased odds of LD.

Habitat suitability map of <em>Ixodes ricinus</em> tick in France using multi-criteria analysis

The tick Ixodes ricinus is widely distributed across Europe and is responsible for the transmission of several pathogens to humans and animals. In this study, we used a knowledge-based method to map variations in habitat suitability for I. ricinus ticks throughout continental France and Corsica. The multi-criteria decision analysis (MCDA) integrated four major biotic and abiotic factors known to influence tick populations: climate, land cover, altitude and the density of wild ungulates. For each factor, habitat suitability index (HSI) values were attributed to different locations based on knowledge regarding its impact on tick populations. For the MCDA, two methods of factor combination were tested, additive and multiplicative, both which were evaluated at the spatial scales of departments and local municipalities. The resulting habitat suitability maps (resolution=100x100 m) revealed that conditions are suitable for I. ricinus over most of France and Corsica. Particularly suitable habitats were located in central, north-eastern and south-western France, while less-suitable habitats were found in the Mediterranean and mountainous regions. To validate the approach, the HSI scores were compared to field data of I. ricinus nymph abundance. Regardless of scale, the correlation between abundance indicator and HSI score was stronger for the additive than for the multiplicative approach. Overall, this study demonstrates the value of MCDA for estimating habitat suitability maps for I. ricinus abundance, which could be especially useful in highlighting areas of the tick's distribution where preventive measures should be prioritised.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13222-9.

Spatiotemporal trends and socioecological factors associated with Lyme disease in eastern Ontario, Canada from 2010-2017

Currently, there is limited knowledge about socioeconomic, neighbourhood, and local ecological factors that contribute to the growing Lyme disease incidence in the province of Ontario, Canada. In this study, we sought to identify these factors that play an important role at the local scale, where people are encountering ticks in their communities. We used reported human Lyme disease case data and tick surveillance data submitted by the public from 2010–2017 to analyze trends in tick exposure, spatiotemporal clusters of infection using the spatial scan statistic and Local Moran’s I statistic, and socioecological risk factors for Lyme disease using a multivariable negative binomial regression model. Data were analyzed at the smallest geographic unit, consisting of 400–700 individuals, for which census data are disseminated in Canada. We found significant heterogeneity in tick exposure patterns based on location of residence, with 65.2% of Lyme disease patients from the city of Ottawa reporting tick exposures outside their health unit of residence, compared to 86.1%—98.1% of patients from other, largely rural, health units, reporting peri-domestic exposures. We detected eight spatiotemporal clusters of human Lyme disease incidence in eastern Ontario, overlapping with three clusters of Borrelia burgdorferi-infected ticks. When adjusting for population counts, Lyme disease case counts increased with larger numbers of Borrelia burgdorferi-infected ticks submitted by the public, higher proportion of treed landcover, lower neighbourhood walkability due to fewer intersections, dwellings, and points of interest, as well as with regions of higher residential instability and lower ethnic concentration (Relative Risk [RR] = 1.25, 1.02, 0.67–0.04, 1.34, and 0.57, respectively, p < .0001). Our study shows that there are regional differences in tick exposure patterns in eastern Ontario and that multiple socioecological factors contribute to Lyme disease risk in this region.

Tick-Borne Encephalitis Risk Increases with Dog Ownership, Frequent Walks, and Gardening: A Case-Control Study in Germany 2018-2020

In Germany, tick-borne encephalitis (TBE) infections mainly occur in southern regions. Despite recent increases in incidence, TBE vaccination coverage remains low, necessitating additional preventive strategies against TBE. Our case-control study in Southern Germany from 2018 to 2020 mapped knowledge/application of tick-protective strategies and identified TBE risk factors. We calculated odds ratios (OR), with 95% confidence intervals (CI). We interviewed 581 cases and 975 matched controls. Most participants recalled lifetime tick bites, mainly while walking, gardening, or hiking. However, only 45% of cases noticed ticks during exposure time; another 12% reported unpasteurized milk intake. While tick-protection knowledge was satisfactory, application lagged behind. Risk factors included dog ownership (OR = 2.45, 95% CI: 1.85−3.24), walks ≥ 4×/week (OR = 2.11, 95% CI: 1.42−3.12), gardening ≥ 4×/week (OR = 1.83, 95% CI: 1.11−3.02), and garden proximity < 250 m of forests (OR = 2.54, 95% CI: 1.82−3.56). Applying ≥2 tick-protective strategies (OR = 0.52, 95% CI: 0.40−0.68) and keeping lawns mowed (OR = 0.63, 95% CI: 0.43−0.91) were inversely associated with TBE. In 2020 (likely pandemic-related), cases reported significantly more walks than previously, potentially explaining the record high case numbers. Our findings provide guidance on targets for TBE prevention. Persons with gardens near forests, frequent outdoor activities, or dogs could particularly benefit from targeted information, including on vaccination and preventing tick bites.

Effects of tick surveillance education on knowledge, attitudes, and practices of local health department employees

BACKGROUND

The number of cases of tick-borne diseases in humans is increasing rapidly within Illinois. The responsibility for increased surveillance of tick-borne disease cases and tick vectors is being placed on local health departments throughout the United States, but they often lack the funding, time, and/or training needed to perform said surveillance. The aims of this study were to develop, deliver, and determine the effectiveness of tick surveillance training workshops for local health department employees within Illinois.

METHODS

We developed and delivered in-person training at local health department offices in each of six Illinois Department of Public Health Environmental Health Regions between April-May of 2019. Pre-, post-, and six-month follow-up questionnaires on knowledge, attitudes, and practices with regards to tick surveillance were administered to training participants. Paired student's t-test or Wilcoxon signed-rank test were used to compare knowledge, attitudes, and practices scores between questionnaires with Cohen's d being used to calculate effect sizes associated with t-tests. McNemar's and McNemar-Bowker tests were used to evaluate individual questions. Spearman's rank correlation was used to evaluate the relationship between knowledge, attitudes, and practices at pre-, post-, and six-month follow-up.

RESULTS

Seventy-six employees from 40 local health departments that represent 44% (45/102) of Illinois counties attended at least one training workshop. Of these attendees, 81.5% (62/76) participated in at least one survey, 79% (60/76) in the in-person pre-training survey, 74% (56/76) in the in-person post-training survey, and 22% (17/76) in the online six-month follow-up survey. The average knowledge score was significantly increased by 8.21 (95% CI:7.28-9.14) points from pre-training to post-training. The average overall attitude score significantly increased by 5.29 (95% CI: 3.91-6.66) points from pre- to post-training. There were no significant differences in practice scores.

CONCLUSIONS

Our study found the training was effective in increasing the knowledge of ticks, tick-borne diseases, and surveillance as well as promoting positive attitudes related to surveillance. While the training, by itself, was not associated with increases in surveillance practices, we were able to empower local public health officials with the knowledge and positive attitudes needed to enact change.

Occupational Lyme Disease: A Systematic Review and Meta-Analysis

Lyme disease (LD) can have significant consequences for the health of workers. The frequency of infection can be estimated by using prevalence and incidence data on antibodies against Borrelia Burgdoferi (BB). A systematic search of studies published in English between 2002 and 2021 and a meta-analysis were conducted in PubMed/Medline, Web of Science, Scopus, and Google Scholar databases. Out of a total of 1125 studies retrieved, 35 articles were included in the systematic review. Overall, in these studies, outdoor workers showed a 20.5% BB seroprevalence rate. Meta-analysis, performed on 15 studies (3932 subjects), revealed a significantly increased risk in outdoor activities (OR 1.93 95%CI 1.15–3.23), with medium-level heterogeneity (I² = 69.2%), and non-significant publication bias. The estimated OR in forestry and agricultural workers was 2.36 (CI95% 1.28; 4.34) in comparison with the controls, while a non-significant increase in risk (OR = 1.05, CI95% 0.28; 3.88) was found in the remaining categories of workers (veterinarians, animal breeders, soldiers). The estimated pooled risk was significantly higher in the studies published until 2010 (OR 3.03 95%CI 1.39–6.61), while in more recent studies the odds became non-significant (OR 1.08 95% CI 0.63–1.85). The promotion of awareness campaigns targeting outdoor workers in endemic areas, and the implementation of local programs aimed at controlling range expansion of vectors, are key strategies for protecting workers.

Prevalence of Risk and Protective Factors for Tick Exposure and Tick-Borne Disease Among Residents of Indiana

OBJECTIVE

To determine the prevalence of risk and protective factors for tick exposure and tick-borne disease (TBD) based on gender and living in urban or rural areas (urbanicity) among a cross section of Indiana adults.

METHODS

Data were collected from 3003 adults (81% response rate) spread across all 92 Indiana counties. Study participants were recruited from existing online panels maintained by Qualtrics. We calculated prevalence ratio (PR) and 95% confidence interval (CI) of 8 primary outcomes for 2 different exposures: (1) gender (male/female) and (2) urbanicity.

RESULTS

Female participants were 10% less likely to find a tick on themselves than male participants (PR = 0.90; 95% CI, 0.74-0.99) and significantly more likely to worry about their health and safety because of ticks, whereas males avoided the outdoors less because of worry about ticks. Female participants were significantly more likely to adopt various personal protective measures, specifically because of concern for ticks. Female participants were also less likely to have been told by a health care provider that they have a TBD (PR = 0.53; 95% CI, 0.38-0.75). Rural participants were significantly more likely to report seeing a tick at their residential property (PR = 2.40; 95% CI, 2.11-2.76), report finding ticks on themselves (PR = 1.90; 95% CI, 1.68-2.23), and report finding a tick on a child at their residential property within the past 6 months than urban dwellers (PR = 1.37; 95% CI, 1.06-1.77). In addition, we found that 62% of participants have very high trust in government sources of information on TBD and tick prevention.

CONCLUSIONS

In Indiana, the area around people's residences may constitute an important source of tick exposure for humans. Being exposed to ticks is most prevalent in those living in rural areas of Indiana. Finally, risk factors for TBD are higher among males than among females.

College Students' Knowledge of Ticks in Oklahoma: Assessment and Insights

Ticks (Arachnida: Acari) are common in Oklahoma and may transmit tick-borne diseases (TBDs) to people. Due to the difficulty in reducing tick populations, awareness of tick bite prevention, proper tick removal, and knowledge of when to seek medical treatment are critical. However, outreach and extension programs are hampered by a lack of knowledge of what community members know about ticks. To address this limitation, we surveyed college students enrolled in three non-major Entomology courses at Oklahoma State University in 2018. Of the 483 students invited to take a survey, 224 (46.4%) students took both surveys. Pre-survey responses indicated lower levels of knowledge of tick biology compared to post-survey responses. For both pre- and post-survey respondents, "ticks can jump" and "ticks reside up in trees" received the fewest correct responses. A majority of survey respondents considered Lyme disease to be the predominant TBD in Oklahoma, although it is not established in Oklahoma. Supplemental education overcame these knowledge gaps, with the exception of knowledge of Lyme disease which was still considered to be the predominant TBD in the post-survey. Our results can be used to develop assessment tools to improve extension programs and enhance protection from TBDs.

Impact of Land Use Changes and Habitat Fragmentation on the Eco-epidemiology of Tick-Borne Diseases

The incidence of tick-borne diseases has increased in recent decades and accounts for the majority of vector-borne disease cases in temperate areas of Europe, North America, and Asia. This emergence has been attributed to multiple and interactive drivers including changes in climate, land use, abundance of key hosts, and people's behaviors affecting the probability of human exposure to infected ticks. In this forum paper, we focus on how land use changes have shaped the eco-epidemiology of Ixodes scapularis-borne pathogens, in particular the Lyme disease spirochete Borrelia burgdorferi sensu stricto in the eastern United States. We use this as a model system, addressing other tick-borne disease systems as needed to illustrate patterns or processes. We first examine how land use interacts with abiotic conditions (microclimate) and biotic factors (e.g., host community composition) to influence the enzootic hazard, measured as the density of host-seeking I. scapularis nymphs infected with B. burgdorferi s.s. We then review the evidence of how specific landscape configuration, in particular forest fragmentation, influences the enzootic hazard and disease risk across spatial scales and urbanization levels. We emphasize the need for a dynamic understanding of landscapes based on tick and pathogen host movement and habitat use in relation to human resource provisioning. We propose a coupled natural-human systems framework for tick-borne diseases that accounts for the multiple interactions, nonlinearities and feedbacks in the system and conclude with a call for standardization of methodology and terminology to help integrate studies conducted at multiple scales.

Evidence-based communication on climate change and health: Testing videos, text, and maps on climate change and Lyme disease in Manitoba, Canada

Given the climate crisis and its cumulative impacts on public health, effective communication strategies that engage the public in adaptation and mitigation are critical. Many have argued that a health frame increases engagement, as do visual methodologies including online and interactive platforms, yet to date there has been limited research on audience responses to health messaging using visual interventions. This study explores public attitudes regarding communication tools focused on climate change and climate-affected Lyme disease through six focus groups (n = 61) in rural and urban southern Manitoba, Canada. The results add to the growing evidence of the efficacy of visual and storytelling methods in climate communications and argues for a continuum of mediums: moving from video, text, to maps. Findings underscore the importance of tailoring both communication messages and mediums to increase uptake of adaptive health and environmental behaviours, for some audiences bridging health and climate change while for others strategically decoupling them.

Tick trails: the role of online recreational trail reviews in identifying risk factors and behavioral recommendations associated with tick encounters in Indiana

BACKGROUND

Recreational trails abound across the United States and represent high risk areas for tick exposure. Although online reviews represent a rich source of user information, they have rarely been used in determining the risk of tick exposure during recreational trail use. Based on online user reviews and comments, the purpose of this study was to determine risk factors and behavioral recommendations associated with tick encounters (Tick Presence) on recreational trails in the state of Indiana, U.S.

METHODS

We reviewed 26,016 user comments left on AllTrails.com for 697 Indiana trails. Reviews were evaluated to determine Tick Presence/Absence, the total number of Tick Presence Reviews per trail, and multiple trail and user behavioral characteristics. We used hot spot (Getis-Ord Gi*) analysis to test the hypothesis of whether there are clusters in the number of Tick Presence Reviews. Pearson chi-square tests of independence evaluated whether tick presence was associated with several trail characteristics. Finally, negative binomial regression evaluated the strength of the association between the number of Tick Presence Reviews and several trail characteristics.

RESULTS

Tick Presence was recorded at 10% (n = 65) of trails and occurred most frequently in May. Hot spot analysis revealed statistically significant clusters of Tick Presence Reviews on trails in the Southern Indiana State Region. Results of χ2 tests indicated significant associations between Tick Presence Reviews and (a) State Region and (b) Land Management Type; Mann-Whitney U tests detected significant differences in Tick Presence Reviews based on Trail Length and Elevation Gain. Subsequent results of a negative binomial regression model indicated that Southern Indiana State Region, Federal and Private Land Management Type, and Elevation Gain were factors significantly associated with Tick Presence Reviews. Content of user reviews indicated several behaviors employed to prevent tick encounters, particularly Repellent Application and Recreational Deterrence; 25% included a behavior Recommendation to others.

CONCLUSIONS

Online, user-generated trail reviews have the potential to serve as rich data sources for identifying recreational trails, where 1) the risk of tick exposure is great, 2) more robust active tick and tick-borne pathogen surveillance may be warranted, and 3) tailored prevention interventions are needed.

Public perceptions of Lyme disease and climate change in southern Manitoba, Canada: making a case for strategic decoupling of climate and health messages

BACKGROUND

Despite scientific evidence that climate change has profound and far reaching implications for public health, translating this knowledge in a manner that supports citizen engagement, applied decision-making, and behavioural change can be challenging. This is especially true for complex vector-borne zoonotic diseases such as Lyme disease, a tick-borne disease which is increasing in range and impact across Canada and internationally in large part due to climate change. This exploratory research aims to better understand public risk perceptions of climate change and Lyme disease in order to increase engagement and motivate behavioural change.

METHODS

A focus group study involving 61 participants was conducted in three communities in the Canadian Prairie province of Manitoba in 2019. Focus groups were segmented by urban, rural, and urban-rural geographies, and between participants with high and low levels of self-reported concern regarding climate change.

RESULTS

Findings indicate a broad range of knowledge and risk perceptions on both climate change and Lyme disease, which seem to reflect the controversy and complexity of both issues in the larger public discourse. Participants in high climate concern groups were found to have greater climate change knowledge, higher perception of risk, and less skepticism than those in low concern groups. Participants outside of the urban centre were found to have more familiarity with ticks, Lyme disease, and preventative behaviours, identifying differential sources of resilience and vulnerability. Risk perceptions of climate change and Lyme disease were found to vary independently rather than correlate, meaning that high climate change risk perception did not necessarily indicate high Lyme disease risk perception and vice versa.

CONCLUSIONS

This research contributes to the growing literature framing climate change as a public health issue, and suggests that in certain cases climate and health messages might be framed in a way that strategically decouples the issue when addressing climate skeptical audiences. A model showing the potential relationship between Lyme disease and climate change perceptions is proposed, and implications for engagement on climate change health impacts are discussed.

Do-It-Yourself Tick Control: Granular Gamma-Cyhalothrin Reduces Ixodes scapularis (Acari: Ixodidae) Nymphs in Residential Backyards

Lyme disease is the most common vector-borne disease in the United States with hotspots in the Northeast and Midwest. Integrated vector control for mosquito-borne disease prevention is often organized at the community level, but tick control is primarily coordinated at the household and individual level. Management of the blacklegged tick, Ixodes scapularis (Say), the vector of the causative agent of Lyme disease in the Midwest and eastern United States in peridomestic environments may be critical as many tick encounters are reported to occur in the yard. Therefore, we assessed the effectiveness of a widely available and low-cost pesticide that targets common lawn pests and is labeled for use against ticks. In June 2019, we evaluated a granular form of gamma-cyhalothrin in a placebo-controlled residential backyard study (n = 90) in two communities in Wisconsin. The product applied by the research team reduced nymphal blacklegged ticks in plots established in the lawn part of the ecotone by 97% one week after application at both communities and by 89-97% three to four weeks postapplication. The proportion of homes with at least one nymphal tick postapplication was significantly lower at acaricide-treated homes and ranged from 4.2 to 29.2% compared with placebo homes where at least one nymphal tick was found at 50-81.5% of homes. These results support the efficacy of a low-cost do-it-yourself strategy for homeowners seeking to reduce blacklegged ticks in the yard.

Assessing Recognition of the Vector of Lyme Disease Using Resin-Embedded Specimens in a Lyme Endemic Area

Lyme disease (LD) is the most common vector-borne disease in the United States. To assess whether a tick bite puts someone at risk for LD, adequate tick identification skills are needed. We surveyed residents of a high LD-incidence state, Wisconsin, on their ability to distinguish ticks from insects and to identify the specimens that could transmit the LD causative agent. Surveys were conducted using resin blocks with four insects and four tick specimens embedded. About half of the participants (64 of 130) recognized all of the ticks, and 60% of those individuals chose only ticks and no insects. Younger participants (18- to 44-yr old) were more likely to identify ticks correctly compared with those 45 yr and older. Participants who agreed strongly with the statement 'I know a lot about ticks` were also likelier to correctly identify ticks. When asked to identify which specimens could transmit LD, less than 25% of participants chose both the Ixodes scapularis Say adult female and nymph and about half of those (15% of participants) picked only those two and no other specimens. Although the relatively small convenience sample was biased toward younger participants who consider themselves 'outdoorsy', results showed that further assessments of tick recognition skills are needed to understand what determines whether people can recognize medically important ticks and to evaluate the potential benefits of enhanced education. In addition to the value of the resin blocks as research tools, the blocks may be useful as training tools to improve tick check efficacy.

Tick exposures and alpha-gal syndrome: A systematic review of the evidence

Alpha-gal syndrome (AGS) refers to a delayed allergic reaction to galactose-α-1,3-galactose (α-Gal) that occurs following the consumption of mammalian meat or exposure to other animal-based foods and products. Increasing evidence suggests that bites from certain tick species can lead to AGS through sensitization of a person's α-Gal specific IgE levels. This systematic review aimed to summarize the published evidence on this topic to understand post-tick exposure AGS epidemiology and health outcomes. A structured search for literature in eight bibliographic databases was conducted in January, 2020. Grey literature and verification searches were also performed. The exposure of interest was tick bites, and the outcome of interest was AGS. All primary research study designs were eligible for inclusion. References were screened for relevance, and data extraction and risk-of-bias assessment were conducted on relevant studies by two independent reviewers. Data were descriptively and narratively summarized. Of 1390 references screened, 102 relevant articles (103 unique studies) were identified (published from 2009 to 2020). Most studies (76.7 %) were case report or series. These 79 studies reported on 236 post-tick exposure AGS cases from 20 different countries, mostly the United States (33.5 %), Spain (19.5 %), Sweden (18.6 %), and France (12.7 %). The mean case age was 51.3 (SD = 16.7, range 5-85, n = 229), while 68.1 % were male (n = 226). The most commonly reported symptom was urticaria (71.2 %); 51.7 % of cases reported anaphylaxis. Twenty-one observational studies were reported, mostly (95.2 %) among clinical allergy patients. The proportion of AGS cases that recalled tick bites was highly variable across these studies. Three challenge studies evaluating tick exposures and α-Gal levels in α-Gal deficient mice were identified. The existing evidence suggests tick bites lead to α-Gal-specific IgE sensitization, which can cause AGS, but further research is needed to clarify if AGS is only attributable to certain tick species and whether other vectors may trigger AGS. Additional research is needed on risk factors for AGS development, evaluation of diagnostic immunoassays, and the epidemiology and distribution of AGS in different populations. Climate change will likely lead to future cases of AGS in new regions worldwide due to the predicted alteration of suitable tick habitats.

Benefits and Drawbacks of Citizen Science to Complement Traditional Data Gathering Approaches for Medically Important Hard Ticks (Acari: Ixodidae) in the United States

Tick-borne diseases are increasing in North America. Knowledge of which tick species and associated human pathogens are present locally can inform the public and medical community about the acarological risk for tick bites and tick-borne infections. Citizen science (also called community-based monitoring, volunteer monitoring, or participatory science) is emerging as a potential approach to complement traditional tick record data gathering where all aspects of the work is done by researchers or public health professionals. One key question is how citizen science can best be used to generate high-quality data to fill knowledge gaps that are difficult to address using traditional data gathering approaches. Citizen science is particularly useful to generate information on human-tick encounters and may also contribute to geographical tick records to help define species distributions across large areas. Previous citizen science projects have utilized three distinct tick record data gathering methods including submission of: 1) physical tick specimens for identification by professional entomologists, 2) digital images of ticks for identification by professional entomologists, and 3) data where the tick species and life stage were identified by the citizen scientist. We explore the benefits and drawbacks of citizen science, relative to the traditional scientific approach, to generate data on tick records, with special emphasis on data quality for species identification and tick encounter locations. We recognize the value of citizen science to tick research but caution that the generated information must be interpreted cautiously with data quality limitations firmly in mind to avoid misleading conclusions.

Support for deer herd reduction on offshore Islands of Maine, U.S.A

Over the past three decades, citizens of Maine in the northeastern United States have experienced increasing blacklegged tick (Ixodes scapularis) abundance and rising incidence of Lyme and other tick-borne diseases. White-tailed deer (Odocoileus virginianus) overabundance has been considered one cause of the high incidence of tick-borne diseases on offshore islands of New England. Most of Maine's 15 offshore, unbridged island communities have a history of concern about ticks, Lyme disease, and white-tailed deer overabundance, but have been challenged to keep deer numbers down through hunting or culls. This history has led to perennial, often divisive community debates about whether and how to reduce the size of their deer herds. In 2016 we conducted a convenience sample survey of year-round and summer residents of Maine's offshore islands to quantify the level of concern about Lyme disease, and assess the motivations and level of support for deer herd reduction. Among respondents, 84 % agreed Lyme disease was a problem on their island and 61 % supported deer herd reduction. Agreement that Lyme disease was a problem was associated with having acquired tick-borne disease as well as with tick bites without disease. Respondents ranked deer overabundance as a top cause of tick abundance and tick-borne disease and supported deer herd reduction as an approach to reduce the risk of Lyme disease. Other problems associated with deer overabundance (vehicle collisions, damage to landscaping, and damage to forests) also motivated support for deer reduction. Approval of doe permits, an expanded archery season, and sharpshooting as reduction methods was greater than an expanded firearms season. Respondents felt responsibility for tick control fell to the town for the most part, and recognized that multiple factors have contributed to the tick problem in Maine, not just deer.

Regional and Local Temporal Trends of Borrelia burgdorferi and Anaplasma spp. Seroprevalence in Domestic Dogs: Contiguous United States 2013-2019

In 2019, in the United States, over 220,000 and 350,000 dogs tested positive for exposure to Anaplasma spp. and Borrelia burgdorferi, respectively. To evaluate regional and local temporal trends of pathogen exposure we used a Bayesian spatio-temporal binomial regression model, analyzing serologic test results for these pathogens from January 2013 to December 2019. Regional trends were not static over time, but rather increased within and beyond the borders of historically endemic regions. Increased seroprevalence was observed as far as North Carolina and North Dakota for both pathogens. Local trends were estimated to evaluate the heterogeneity of underlying changes. A large cluster of counties with increased B. burgdorferi seroprevalence centered around West Virginia, while a similar cluster of counties with increased Anaplasma spp. seroprevalence centered around Pennsylvania and extended well into Maine. In the Midwest, only a small number of counties experienced an increase in seroprevalence; instead, most counties had a decrease in seroprevalence for both pathogens. These trends will help guide veterinarians and pet owners in adopting the appropriate preventative care practices for their area. Additionally, B. burgdorferi and A. phagocytophilum cause disease in humans. Dogs are valuable sentinels for some vector-borne pathogens, and these trends may help public health providers better understand the risk of exposure for humans.

Development and validation of a behavioral index for adaptation to lyme disease

Background

Recent evidence suggests that climate change and other factors are leading to the emergence of Lyme disease in the province of Quebec, where it previously did not exist. As risk areas expand further north, the population can adopt specific preventive behaviors to limit chances of infection. The objectives of this study were to (1) create an index of Lyme disease prevention behaviors (LDPB), and (2) use the theory of planned behavior (TPB) to explain the decision-making process of people who choose to adopt LDPB.

Methods

A sample of 1959 adults living in a Lyme disease risk area completed a questionnaire by phone (n = 1003) or on the Web (n = 956). The questionnaire measured whether they did or did not adopt the LDPB proposed by public health officials. It also measured some TPB variables, including their attitude or perceived social norms regarding LDPB.

Results

Our findings led to the creation of a Lyme disease prevention index consisting of 10 behaviors, down from the 19 behaviors initially considered for inclusion in the index. Rates of adoption of each behavior varied tremendously, from 4.30 to 83.80%. All variables of the TPB model (attitude, social norms, and perceived control) were significantly associated with intention to adopt preventive behaviors. Intention itself was significantly associated with adoption of LDPB. Likewise, risk perception was positively correlated with the adoption of LDPB.

Conclusions

This study led to the creation of a Lyme disease prevention index that can be used by public health agencies, researchers, and professionals to monitor the evolution over time of individuals’ LDPB adoption rates. It also showed the usefulness of the TPB in understanding the adoption of LDPB and how intention to adopt such behaviors is formed.

Species distribution models for the eastern blacklegged tick, Ixodes scapularis, and the Lyme disease pathogen, Borrelia burgdorferi, in Ontario, Canada

The blacklegged tick, Ixodes scapularis, is established in several regions of Ontario, Canada, and continues to spread into new geographic areas across the province at a rapid rate. This poses a significant public health risk since I. scapularis transmits the Lyme disease-causing bacterium, Borrelia burgdorferi, and other pathogens of potential public health concern. The objective of this study was to develop species distribution models for I. scapularis and B. burgdorferi to predict and compare the potential distributions of the tick vector and the Lyme disease pathogen as well as the ecological factors most important for species establishment. Ticks were collected via tick dragging at 120 sites across southern, central, and eastern Ontario between 2015 and 2018 and tested for tick-borne pathogens. A maximum entropy (Maxent) approach was used to model the potential distributions of I. scapularis and B. burgdorferi. Two independent datasets derived from tick dragging at 25 new sites in 2019 and ticks submitted by the public to local health units between 2015 and 2017 were used to validate the predictive accuracy of the models. The model for I. scapularis showed high suitability for blacklegged ticks in eastern Ontario and some regions along the shorelines of the Great Lakes, and moderate suitability near Algonquin Provincial Park and the Georgian Bay with good predictive accuracy (tick dragging 2019: AUC = 0.898; ticks from public: AUC = 0.727). The model for B. burgdorferi showed a similar predicted distribution but was more constrained to eastern Ontario, particularly between Ottawa and Kingston, and along Lake Ontario, with similarly good predictive accuracy (tick dragging 2019: AUC = 0.958; ticks from public: AUC = 0.863. The ecological variables most important for predicting the distributions of I. scapularis and B. burgdorferi included elevation, distance to deciduous and coniferous forest, proportions of agricultural land, water, and infrastructure, mean summer/spring temperature, and cumulative annual degree days above 0°C. Our study presents a novel application of species distribution modelling for I. scapularis and B. burgdorferi in Ontario, Canada, and provides an up to date projection of their potential distributions for public health knowledge users.

Context matters: Contrasting behavioral and residential risk factors for Lyme disease between high-incidence states in the Northeastern and Midwestern United States

The dynamics of zoonotic vector-borne diseases are determined by a complex set of parameters including human behavior that may vary with socio-ecological contexts. Lyme disease is the most common vector-borne disease in the United States. The Northeast and upper Midwest are the regions most affected - two areas with differing levels of urbanization and differing sociocultural settings. The probability of being infected with Lyme disease is related to the risk of encounters with Ixodes scapularis ticks infected with Borrelia burgdorferi sensu lato, which reflects both the environmental tick hazard and human behaviors. Herein, we compare behavioral and peridomestic risk factors perceived to influence the risk for human-tick encounters between two high-incidence states in the Northeast (New York and New Jersey) and one high-incidence state in the Midwest (Wisconsin). We used a smartphone application, The Tick App, as a novel survey tool, during spring and summer of 2018. Adaptive human behavior was identified in the relationship between outdoor activities and the use of methods to prevent tick bites. More frequent recreational outdoor activities and gardening (a peridomestic activity) were associated with a 1.4-2.3 times increased likelihood of using personal protective measures to prevent tick bites, when accounting for demographics and previous Lyme diagnosis. Most outdoor activities were more frequently reported by participants from the Midwest (n = 697), representing an older demographic, than the Northeast (n = 396). Participants from the Northeast were less likely to report use of personal protective measures to prevent tick bites, but a larger proportion of participants from the Northeast reported application of environmental pesticides targeting ticks or mosquitoes or other insects on their property (34 % of 279 versus 22 % of 616 participants) and interventions to reduce the presence of peridomestic deer compared to participants from the Midwest (e.g. 20 % of 278 versus 7% of 615 participants reported having a deer proof fence). Participants from the Midwest were more likely to kill rodents on their property (28 % versus 13 %). These differences illustrate the need for further assessment of personal behavior and tick exposure in these two Lyme disease-endemic regions to aid in targeted public health messaging to reduce tick-borne diseases.

Knowledge, Attitudes, Practices (KAP) of Italian Occupational Physicians towards Tick Borne Encephalitis

Tick-Borne Encephalitis (TBE) is an occupational health threat with increasing incidence in the geographic area of Italy. Despite this, TBE vaccination rates have ranged from 10% to 40% in Italy, even in at-risk workers. The reasons for this low rate are investigated in this present study of the knowledge, attitudes, and practices of occupational physicians (OP) regarding TBE disease and vaccination in at-risk workers. A total of 229 OP participated in an internet-based survey by completing a structured questionnaire. Adequate general knowledge of TBE disease was found in 58% of OP. Accurate perception of TBE risk in occupational settings was found in 20%. TBE vaccination for at-risk workers was recommended by 19%. Willingness to recommend TBE vaccination was more likely by OP practicing in endemic areas (Odds Ratio 3.10, 95% confidence intervals 1.47–6.55), who knew the existence of the term “arboviruses” (3.10, 1.29–7.44), or exhibited a better understanding of TBE (2.38, 1.11–5.12)—and were positive predictors for promoting TBE vaccine, while acknowledging that TBE as a severe disease was a negative one. Tick-borne disorders in Italy are a still rare (but increasing) occupational health threat, and vaccination gaps for TBE virus may find an explanation in OP incomplete knowledge of evidence-based recommendations.

Livestock owners' worry and fear of tick-borne diseases

Background

Recent global changes have led to an increase in distribution of ticks towards higher elevation and latitude in Europe and livestock are at increasing risk of contracting tick-borne diseases, but psychological aspects of how this affects human well-being are rarely assessed. Departing from the theory on emotional appraisal coming from psychology, this study investigates which factors that modulate worry and fear associated with the presence of ticks among livestock owners of sheep and/or cattle.

Methods

Survey data from 775 livestock owners in Norway were analysed by hierarchical multiple regression analysis with an index of fear of tick-borne diseases among livestock as the outcome variable.

Results

Twenty-nine per cent of the livestock owners reported worry and fear of tick-borne diseases among their livestock. The model explained 35% of the variance in worry and fear. There was a weak association between estimated incidences of tick-borne diseases in livestock and livestock owners’ worry and fear. Whereas previous personal experience of ticks and tick-borne diseases in livestock, and the livestock owners’ appraisals of the situation were more strongly associated with relatively stronger feelings of worry and fear.

Conclusions

Livestock owners’ worry and fear of tick-borne diseases in livestock can partly be understood as their appraisals of perceived personal relevance of the presence of ticks, its potential negative implications for their daily life at large, and what potential they have to cope by different strategies to adapt or adjust to the situation.

Telephone versus web panel National Survey for monitoring adoption of preventive behaviors to climate change in populations: a case study of Lyme disease in Québec, Canada

BACKGROUND

To monitor the adoption of climate change adaptive behaviors in the population, public health authorities have to conduct national surveys, which can help them target vulnerable subpopulations. To ensure reliable estimates of the adoption of these preventive behaviors, many data collection methods are offered by polling firms. The aim of this study was to compare a telephone survey with a web survey on Lyme disease with regard to their representativeness.

METHODS

The data comes from a cross-sectional study conducted in the Province of Québec (Canada). In total, 1003 people completed the questionnaire by telephone and 956 filled in a web questionnaire. We compared the data obtained from both survey modes with the census data in regard to various demographic characteristics. We then compared the data from both samples in terms of self-reported Lyme disease preventive behaviors and other theoretically associated constructs. We also assessed the measurement invariance (equivalence) of the index of Lyme disease preventive behaviors across the telephone and web samples.

RESULTS

Findings showed that neither the telephone nor the web panel modes of data collection can be considered more representative of the target population. The results showed that the proportion of item non-responses was significantly higher with the web questionnaire (5.6%) than with the telephone survey (1.3%), and that the magnitude of the differences between the two survey modes was nil for 19 out of the 30 items related to Lyme disease, and small for 11 of them. Results from invariance analyses confirmed the measurement invariance of an index of adaptation to Lyme disease, as well as the mean invariance across both samples.

CONCLUSIONS

Our results suggested that both samples provided similar estimates of the level of adaptation to Lyme disease preventive behaviors. In sum, the results of our study showed that neither survey mode was superior to the other. Thus, in studies where adaptation to climate change is monitored over time, using a web survey instead of a telephone survey could be more cost-effective, and researchers should consider doing so in future surveys on adaptation to climate. However, we recommend conducting a pretest study before deciding whether to use both survey modes or only one of them.

Lyme disease prevention: A content analysis of Canadian patient group and government websites

The quality of information presented on health-related websites-in terms of comprehensiveness, accuracy and consistency-is a public health concern. To date, the consistency of information across Canadian websites devoted to Lyme disease (LD) prevention has not been evaluated. The first aim of this study was to describe the contents and recommendations of LD prevention websites provided by two types of Canadian organizations: government (n = 3) and patient groups (n = 3). A second objective was to analyse the level of convergence among these websites in terms of their prevention-related content. Initial coding of the content resulted in information segments grouped into 114 subthemes related to nine overarching themes: tick habitat suitability, risk period, transmission, personal protection, peridomestic environmental management, tick identification and removal, early symptoms, testing and diagnosis and preventive treatment. Comparative content analyses were performed both within and between the content of websites of the two organization types. The themes most frequently addressed by both organization types were personal protection (20% of the prevention-related content in patient group websites and 22% of the prevention-related content in government websites), transmission (12% and 16%, respectively) and tick identification and removal (19% and 15%, respectively). Government websites' information was generally convergent with that of patient group websites (four highly convergent themes, three moderately convergent and two divergent). Nevertheless, of particular concern were divergent messages and inaccurate information found on 11 subthemes out of 103. Examples included other possible modes of transmission and the ineffectiveness of DEET insect repellent. These results suggest the need for public health and health communications research on the issue of the quality of LD prevention information found on the Internet.

Seasonality and anatomical location of human tick bites in the United Kingdom

Tick bites on humans can occur in a variety of habitats and may result in the transmission of tick-borne pathogens, such as the causative agent of Lyme borreliosis (LB), Borrelia burgdorferi sensu lato. As the risk of transmission of this pathogen to the host increases with the duration of tick feeding, the recognition and removal of ticks as soon as possible following attachment is important for reducing the risk of infection. Performing a thorough body examination for ticks following potential exposure is recommended by tick awareness campaigns. Knowledge of where on the body feeding ticks are frequently found, and at which times of year peak tick exposure occurs, provides important information for public health messaging and may aid those bitten by ticks to engage more effectively with tick-checking behaviour. This paper summarizes human tick bites in the United Kingdom (UK) during 2013-2018 reported to Public Health England's passive Tick Surveillance Scheme and further examines the anatomical location and seasonality of bites from the most commonly encountered tick and LB vector Ixodes ricinus. A total of 1,328 tick records from humans were received of which 93% were I. ricinus. Humans were most commonly bitten by I. ricinus nymphs (70% bites). Tick bites were recorded on all parts of the body, but there were significant differences in their anatomical location on adults and children. Most tick bites on adults occurred on the legs (50%), whereas on children tick bites were mostly on the head and neck (43%). Bites from I. ricinus were recorded throughout the year but were most numerous during May to August. This study adds to the body of research on the seasonality and anatomical location of human tick bites in temperate Europe and highlights the importance of data collected through passive surveillance in addition to research and epidemiological studies.

Systematic review and meta-analysis of tick-borne disease risk factors in residential yards, neighborhoods, and beyond

BACKGROUND

Exposure to blacklegged ticks Ixodes scapularis that transmit pathogens is thought to occur peri-domestically. However, the locations where people most frequently encounter infected ticks are not well characterized, leading to mixed messages from public health officials about where risk is highest.

METHODS

We conducted a systematic review and meta-analysis on spatial risk factors for tick-borne disease and tick bites in eastern North America. We examined three scales: the residential yard, the neighborhood surrounding (but not including) the yard, and outside the neighborhood. Nineteen eligible studies represented 2741 cases of tick-borne illness and 1447 tick bites. Using random effects models, we derived pooled odds ratio (OR) estimates.

RESULTS

The meta-analysis revealed significant disease risk factors at the scale of the yard (OR 2.60 95% CI 1.96 - 3.46), the neighborhood (OR 4.08 95% CI 2.49 - 6.68), and outside the neighborhood (OR 2.03 95% CI 1.59 - 2.59). Although significant risk exists at each scale, neighborhood scale risk factors best explained disease exposure. Analysis of variance revealed risk at the neighborhood scale was 57% greater than risk at the yard scale and 101% greater than risk outside the neighborhood.

CONCLUSIONS

This analysis emphasizes the importance of understanding and reducing tick-borne disease risk at the neighborhood scale. Risk-reducing interventions applied at each scale could be effective, but interventions applied at the neighborhood scale are most likely to protect human health.

TRIAL REGISTRATION

The study was registered with PROSPERO: CRD42017079169 .

Knowledge, attitudes, and behaviors regarding tick-borne disease prevention in endemic areas

As part of a TickNET collaboration we evaluated the knowledge, attitudes, and behaviors related to tick-borne disease (TBD) prevention among persons living in endemic areas of Connecticut (CT) and Maryland (MD). Up-to-date information on the use of various prevention methods, as well as attitudes toward available and potential prevention options, is critical for effective promotion of recommended behaviors. During 2016-2017, printed invitations were mailed via the post office to 27,029 households requesting participation in an online survey regarding knowledge of TBD, risk perceptions, and prevention behaviors. Prevention behaviors included tick checks, showering/bathing, insect repellents, pet tick control, and chemical or natural pesticide use on residential properties. Associations of sociodemographic characteristics and knowledge and attitude variables with prevention behaviors were assessed in unadjusted analyses and multivariable models to calculate adjusted odds ratios (aOR). Participants were also asked if they would be willing to get a Lyme disease (LD) vaccine, if one becomes available. Overall, 1883 (7%) persons completed the survey. Participants reported using preventive behaviors most of the time or always as follows: pet tick control (83%), tick checks (58%), showering/bathing (42%), insect repellent (31%), and chemical (23%) or natural (15%) pesticides on property. Self-rated knowledge of LD, perceived prevalence of LD, perceived severity of LD, and perceived likelihood of contracting LD or another TBD were significantly (p < 0.05) associated with performing a tick check [aOR 2.5, aOR 1.71, aOR 1.36, aOR 1.83, respectively]. Female gender and perceived prevalence of LD were significantly associated with applying insect repellent [aOR 1.56, aOR 1.64, respectively]. Perceived prevalence of LD was significantly associated with showering or bathing, insect repellents, and pet tick control [aOR 1.42, aOR 1.64, aOR 1.92, respectively]. Income > $100,000 was significantly associated with applying a chemical or natural pesticide to one's property [aOR 1.29, aOR 1.40, respectively]. A majority of respondents (84%) reported that they were very likely or somewhat likely to get a LD vaccine if one were available. Few behaviors (tick checks and pet tick control) were reported to be practiced by more than half of the respondents living in LD endemic areas. Perceived prevalence of LD was the only factor associated with performing most of the prevention behaviors (tick checks, showering/bathing, use of insect repellents, and pet tick control). Use of chemical or natural pesticides appears to be driven by income. Greater efforts are needed to encourage use of prevention behaviors in endemic areas, and this may be facilitated by increasing awareness of local prevalence.

Knowledge, habits and attitudes towards TBE and other tick-borne diseases in German forestry trainees

Tick-borne encephalitis (TBE) is an occupational hazard for forestry workers. We measured knowledge levels, misbeliefs, and vaccination rates in forestry trainees in order to tailor specific measures aimed at reducing occupational TBE incidence. A paper-based survey was performed at a central training site for forestry workers in the state of Baden-Wuerttemberg. The questionnaire contained items regarding vaccination status against tick-borne encephalitis virus (TBEV), self-reported tick-borne diseases, knowledge of and attitudes towards tick-borne disease, and practices in the context of ticks and tick bites. All trainees in the period June-December 2018 were surveyed. Statistical analyses were conducted using Mann-Whitney-Rank sum test and one-way ANOVA tests. Two-hundred-twenty-five trainees participated in the survey. Almost all (>99%) were aware of living in a TBE high-risk area. Eighty-three percent of respondents were vaccinated in line with current recommendations. Seventeen percent had no effective vaccination status. Twenty-seven percent believed that ticks can transmit only TBEV and Borrelia spp. Sixty-two percent knew that TBEV infections can be fatal. Only 8% of respondents use tick repellents and only 17% wear long sleeves and pants. Trainees who graduated from a six and (eight or) nine secondary school (Realschule and Abitur respectively) had more knowledge on ticks and tick-borne disease compared to graduates from a five year school (Hauptschule) (p = 0.002 and p = 0,037 respectively). Overall, the TBE vaccination rate is not high enough in this high-risk occupational group. We identified gaps in knowledge and practices that could have an impact on TBE incidence in this group if addressed. Further epidemiological research is needed on knowledge, attitudes, and practices in different high-risk populations.

Knowledge, Attitudes, and Practices on Tick-Borne Human Diseases and Tick-Borne Encephalitis Vaccine among Farmers from North-Eastern Italy (2017)

Objectives: Tick-borne diseases (T-BD) represent a potential health threat for outdoor workers in endemic areas, such as the Autonomous Province of Trento (APT). We conducted a questionnaire-based survey to assess T-BD knowledge, attitudes, and preventive practices among APT farmers, specifically focusing on the use of protective habits and the uptake of the tick-borne encephalitis (TBE) vaccine.Methods: A convenience sample of 106 farmers (all males, mean age 47.3 ± 13.6 years) attending pesticide training courses (12/2016-03/2017) completed the anonymous survey. Binary regression analysis, calculations of multivariate odds ratios (mOR) and 95% confidence intervals were used to assess knowledge, attitudes, and risk perceptions as predictors of preventive measures.Results: Though general understanding of T-BD was fairly low, the majority of the participants perceived TBE infection as a frequent (73.6%) and severe disease (61.3%). Overall, 43.3% of participants knew a TBE vaccine was available, and 24.5% had been vaccinated. Protective habits were reported by 53.8% of respondents, with self-checks for tick bites particularly low at 2.8% of participants. Better knowledge of T-BD and favorable attitudes toward vaccinations were associated with TBE immunization (mOR 4.708; 95%CI 1.273-17.409 and mOR 3.555; 95%CI 1.175-10.760, respectively), while previous history of tick bite and any interaction with T-BD significantly predicted adherence to protective measures (mOR 4.458; 95%CI 1.808-10.991, and mOR 9.433; 95%CI 1.127-78.973, respectively).Conclusions: Adherence to preventive measures (TBE vaccine) and protective habits was unsatisfactory in our sampled group, being a possible consequence of significant knowledge gaps. Public health communication on T-BD in farmers should, therefore, target understanding of health issues and appropriate preventive measures.