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.

Can protection motivation theory predict protective behavior against ticks?

BACKGROUND

Cases of reported tick-borne diseases in humans have increased over the past decades. Strategies informing the public about ticks, their associated diseases, and preventive measures are often highlighted as important in limiting pathogen transfer and disease. However, knowledge about the motivation for people to apply preventative measures is sparse.

METHODS

The aim was to examine if Protection Motivation Theory, a model of disease prevention and health promotion, can predict the use of protective measures against ticks. Ordinal logistic regression and Chi-square tests were used on data from a cross-sectional survey with respondents from Denmark, Norway, and Sweden (n = 2658). We examined the effect of (1) the perceived seriousness of tick bites, Lyme borreliosis (LB), and tick-borne encephalitis (TBE), and (2) the perceived probability of getting a tick bite, Lyme borreliosis, and tick-borne encephalitis on protection against ticks. Finally, we examined if there was an association between the use of a protective measure and the perceived efficacy of that measure.

RESULTS

The perceived seriousness of a tick bite and LB significantly predict who is more likely to apply protective measures for all three countries combined. The perceived seriousness of TBE did not significantly predict the level of adoption of protective measures applied by respondents. The perceived likelihood of getting a tick bite within the next 12 months and the perceived likelihood of getting LB if bitten by a tick significantly predicted the application of protective measures. However, the increases in the likelihood of protection were very small. The application of a certain type of protection was always correlated with the perceived efficacy of the same protective measure.

CONCLUSION

Some variables of PMT may be used to predict the level of adoption of protection applied against ticks and tick-borne diseases. We found that the perceived seriousness of a tick bite and LB significantly predict the level of adoption protection. The perceived likelihood of getting a tick bite or LB also significantly predicted the level of adoption of protection, although the change was very small. The results regarding TBE were less clear. Lastly, there was an association between applying a protective measure and the perceived efficacy of the same measure.

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.

Assessing Durability and Safety of Permethrin Impregnated Uniforms Used by Outdoor Workers to Prevent Tick Bites after One Year of Use

Long lasting permethrin-impregnated (LLPI) clothing can retain permethrin and repel ticks for up to three months and without exceeding EPA-approved safe levels; however, little is known about longer term effects of wearing LLPI clothing. Here, permethrin content was measured in new forester pants soon after initial impregnation (Insect Shield) and again one year later after being repeatedly worn by foresters in the field. Urine samples were collected from foresters for biomonitoring of permethrin metabolites at multiple time intervals (pre-use, one-month, three-to-four-months, and one-year post-use). Lethality against nymphal Ixodes scapularis Say was measured in clothing after one year of wear by foresters. Furthermore, to test potential variability in permethrin impregnation of different batches of clothing, separate sets of clothing were anonymously sent to Insect Shield for permethrin treatment over a period of three months and permethrin was quantified. Results demonstrated 33% of participants' pants had no measurable permethrin after one year of wear and permethrin content and tick mortality varied significantly between clothing. Only two of the participants' clothing resulted in ≥ 30% tick mortality after one year of wear. Significant differences were observed in 3-PBA and trans-DCCA, but not cis-DCCA metabolites in participants over the four measured time points and were higher than general United States population levels. This study provides practical information on the safety (measured by urinary metabolites) over time of LLPI clothing. It also provides snapshots (pre-washing and after one year of wear) of effectiveness of LLPI clothing as personal protective equipment against ticks for outdoor workers.

Responses of ticks to immersion in hot bathing water: Effect of surface type, water temperature, and soap on tick motor control

Preventing bites from undetected ticks through bathing practices would benefit public health, but the effects of these practices have been researched minimally. We immersed nymphal and adult hard ticks of species common in the eastern United States in tap water, using temperatures and durations that are realistic for human hot bathing. The effect of (a) different skin-equivalent surfaces (silicone and pig skin), and (b) water temperature was tested on Amblyomma americanum, Dermacentor variabilis and Ixodes scapularis nymphs. Overall, the type of surface had a much larger effect on the nymphs’ tendency to stay in contact with the surface than water temperature did. Most nymphs that separated from the surface did so within the first 10 s of immersion, with the majority losing contact due to the formation of an air bubble between their ventral side and the test surface. In addition, adult Ixodes scapularis were tested for the effect of immersion time, temperature, and soap on tick responsiveness. Some individual adults moved abnormally or stopped moving as a result of longer or hotter immersion, but soap had little effect on responsiveness. Taken together, our results suggest that the surface plays a role in ticks’ tendency to stay in contact; the use of different bath additives warrants further research. While water temperature did not have a significant short-term effect on tick separation, ticks that have not attached by their mouth parts may be rendered unresponsive and eventually lose contact with a person’s skin in a hot bath. It should be noted that our research did not consider potential temperature effects on the pathogens themselves, as previous research suggests that some tickborne pathogens may become less hazardous even if the tick harboring them survives hot-water exposures and later bites the bather after remaining undetected.

Barriers to Effective Tick Management and Tick-Bite Prevention in the United States (Acari: Ixodidae)

Lyme and other tick-borne diseases are increasing in the United States. Development of tick control tools have focused primarily on the blacklegged tick, Ixodes scapularis Say. Application of acaricides or entomopathogenic fungal agents to kill host-seeking ticks or ticks on rodents can suppress I. scapularis abundance in residential landscapes, but evidence is lacking for impact on human tick bites or tick-borne disease. Similar studies remain limited for the lone star tick, Amblyomma americanum (L.). Other knowledge gaps include how well homeowners and pest control companies perform in the broadcast application of tick-killing products, relative to high efficacy reported in research studies, and the tick-killing potential of natural product formulations exempt from Environmental Protection Agency registration. Area-wide control based on preventing ticks from feeding on their main reproductive host, the white-tailed deer, can suppress populations of both I. scapularis and A. americanum. Some studies also suggest an impact on Lyme disease cases, but this needs to be further validated in larger-scale intervention studies. The effectiveness, scale, cost, and implementation of various tick management strategies are important considerations in efforts to reduce human tick encounters and tick-borne disease. Additional barriers include weak incentives for industry and academia to develop, test, and register new tick and pathogen control technologies, including vaccines targeting humans, tick reproductive hosts, or wildlife pathogen reservoirs. Solutions will need to be 'two-pronged': improving the tick and pathogen control toolbox and strengthening the public health workforce engaging in tick control at local and state levels.

The Effect of Long-lasting Permethrin Impregnated Socks on Tick Bite in Korea

BACKGROUND

The risk of tick-borne diseases is decreased by increasing awareness and knowledge through prevention education. The aim of the present study was to evaluate the effect of long-lasting permethrin impregnated (LLPI) socks for tick bites.

METHODS

A randomized open label study was conducted to determine the effectiveness of LLPI socks for prevention of tick bites among 367 adults living in a rural area. Participants completed questionnaires at the start of follow-up (July 2014) and at the end of follow-up (December 2014), and tick bites were reported.

RESULTS

A total of 332 subjects completed the follow-up survey. The tick bite rate of the two groups was not significantly different (3.6% vs. 3.1%). But the tick bite rate of lower extremities of subjects wearing LLPI socks was significantly lower compared to that of subjects wearing general socks.

CONCLUSION

The tick bite rate was not different between the two groups, but the tick bite rate of lower extremities of LLPI was significantly lower than general groups. Further study is needed to investigate the effect of LLPI clothes with larger populations.

Preventing tick-bites among children in Indiana, USA: An analysis of factors associated with parental protective behaviors

Despite evidence to the effect that there is low parental adoption of tick-bite personal protective behavior (PPB) for their children - a population at high risk for tick exposure, very limited information is available on factors associated with parental adoption of PPB. The objective of this study was to identify the most significant factors associated with parental adoption of tick-bite PPB on behalf of a child or children at risk of tick encounters. A cross-section of parents in Indiana, USA whose child had spent time outdoors in tick habitat during the summer were recruited from representative online panels maintained by Qualtrics. Binary logistic regression was used to model determinants of five tick-bite PPBs. Our results revealed that the application of tick repellent (89 %, n = 718) followed by conducting a tick check of the child's body soon after returning from the outdoors (84 %, n = 676) were the PPBs most frequently adopted by parents. Conversely, tucking one's shirt into pants and pants into socks was the least frequently adopted PPB (48 %, n = 386). Compared to other factors evaluated in logistic regression models, parents who reported implementing one or more residential tick control practices were significantly more likely to adopt nearly all five tick-bite PPBs for their children. Additionally, parents who were more worried about their health due to ticks and reported being more likely to avoid the outdoors because of ticks were more likely to adopt at least three PPBs on behalf of their children. To ensure children can most safely engage in outdoor activity, identifying the factors associated with parental adoption of tick-bite preventive behaviors represents an important mechanism in the prevention of tick-borne diseases.

Protective Effectiveness of Long-Lasting Permethrin Impregnated Clothing Against Tick Bites in an Endemic Lyme Disease Setting: A Randomized Control Trial Among Outdoor Workers

Tick-borne diseases are a growing threat to public health in the United States, especially among outdoor workers who experience high occupational exposure to ticks. Long-lasting permethrin-impregnated clothing has demonstrated high initial protection against bites from blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), in laboratory settings, and sustained protection against bites from the lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), in field tests. However, long-lasting permethrin impregnation of clothing has not been field tested among outdoor workers who are frequently exposed to blacklegged ticks. We conducted a 2-yr randomized, placebo-controlled, double-blinded trial among 82 outdoor workers in Rhode Island and southern Massachusetts. Participants in the treatment arm wore factory-impregnated permethrin clothing, and the control group wore sham-treated clothing. Outdoor working hours, tick encounters, and bites were recorded weekly to assess protective effectiveness of long-lasting permethrin-impregnated garments. Factory-impregnated clothing significantly reduced tick bites by 65% in the first study year and by 50% in the second year for a 2-yr protective effect of 58%. No significant difference in other tick bite prevention method utilization occurred between treatment and control groups, and no treatment-related adverse outcomes were reported. Factory permethrin impregnation of clothing is safe and effective for the prevention of tick bites among outdoor workers whose primary exposure is to blacklegged ticks in the northeastern United States.

Tick Bite Risk and Tick-Borne Disease Perceptions of School District Administrators in the Mid-Atlantic United States

BACKGROUND

Lyme disease is a common tick-borne disease in the northeastern and midwestern United States. School-aged children aged 5-15 years are at high risk for contracting Lyme disease. Many school campuses in the mid-Atlantic United States are in areas that are near, or border with, wooded habitat.

METHODS

We surveyed school administrators to determine the perception of risk of tick encounters and tick control methods implemented on school campuses in the mid-Atlantic.

RESULTS

Responses from Pennsylvania and New Jersey districts indicate school district administrators had knowledge of Lyme disease and blacklegged ticks, but knowledge of other tick species and tick-borne diseases was limited. Overall, the results suggest that targeted communication of educational information regarding ticks and tick control to school districts could encourage increased participation in organized tick control or other preventative measures.

CONCLUSIONS

Overall, respondents were aware of ticks and Lyme disease, but were not aware or had limited awareness of many other tick-borne diseases, and how tick bite risk could be reduced. Targeted communication of educational information regarding ticks and tick control to school districts could provide a framework for reducing tick-borne disease risk in mid-Atlantic school districts.

Exposure to ticks and undertaking Lyme borreliosis prevention activities among students from Poland and Slovakia

INTRODUCTION AND OBJECTIVE

The incidence of Lyme borreliosis (LB) is increasing in many countries in Europe, including Poland and Slovakia. The aim of the study was to analyze the exposure to tick bites and undertaking LB prevention activities among students of medical fields of studies in Poland (PL) and Slovakia (SK).

MATERIAL AND METHODS

The study was conducted among 611 students from Poland (296 students) and Slovakia (315 students). The applied research tool was the questionnaire. It consisted of questions about exposure to ticks (occurrence of an episode of tick bites, bite site, methods used for tick removal) and the frequency of undertaking preventive actions (using repellents, checking the body after returning from green areas). Pearson Chi-square statistics were calculated to assess significant differences between students from the study countries PL/SK and gender in each country.

RESULTS

Among surveyed students the episode of a tick bite was reported by 352 persons (57.6%). Students from PL most frequently removed ticks with tweezers with a swift, steady movement (26.6%), while students from SK removed the tick by applying a fatty substance so that it would come off by itself (30.1%). Most of the surveyed students, being outdoors, did not apply ticks repellents (34.7%) or used them rarely (48.9%). At the same time, 49.4% of students stated that they always checked the body to search for any attached tick after returning from green areas.

CONCLUSIONS

Considering the fact that the surveyed people were the students of medical fields of studies, and in the future became qualified medical personnel, the frequency of using the analyzed methods of prophylaxis of LB appears to be too small. The results obtained can help in the education of students of medical fields.

Counterattacking the tick bite: towards a rational design of anti-tick vaccines targeting pathogen transmission

Hematophagous arthropods are responsible for the transmission of a variety of pathogens that cause disease in humans and animals. Ticks of the Ixodes ricinus complex are vectors for some of the most frequently occurring human tick-borne diseases, particularly Lyme borreliosis and tick-borne encephalitis virus (TBEV). The search for vaccines against these diseases is ongoing. Efforts during the last few decades have primarily focused on understanding the biology of the transmitted viruses, bacteria and protozoans, with the goal of identifying targets for intervention. Successful vaccines have been developed against TBEV and Lyme borreliosis, although the latter is no longer available for humans. More recently, the focus of intervention has shifted back to where it was initially being studied which is the vector. State of the art technologies are being used for the identification of potential vaccine candidates for anti-tick vaccines that could be used either in humans or animals. The study of the interrelationship between ticks and the pathogens they transmit, including mechanisms of acquisition, persistence and transmission have come to the fore, as this knowledge may lead to the identification of critical elements of the pathogens' life-cycle that could be targeted by vaccines. Here, we review the status of our current knowledge on the triangular relationships between ticks, the pathogens they carry and the mammalian hosts, as well as methods that are being used to identify anti-tick vaccine candidates that can prevent the transmission of tick-borne pathogens.

Bioabsorption and effectiveness of long-lasting permethrin-treated uniforms over three months among North Carolina outdoor workers

BACKGROUND

Vector-borne diseases are an important cause of morbidity and mortality in the USA. Effective, convenient prevention methods are needed. Long-lasting permethrin-impregnated (LLPI) clothing can prevent tick bites, however, additional information is needed on the real-world effectiveness and safety of this preventative measure.

METHODS

In this pilot study, we recruited state and county park employees from North Carolina to wear LLPI uniforms for three months during the summer of 2016. We collected spot urine samples for biomonitoring of permethrin metabolites at one week, one month and three months after first use of the LLPI uniform. Following three months of wear, we collected pants and socks and analyzed them for permethrin content and mortality to ticks and mosquitoes.

RESULTS

Thirteen park employees were included in the analysis. Bioactive amounts of permethrin remained in all clothing swatches tested, although there was great variability. Tick mortality was high, with 78% of pant and 88% of sock swatches having mean knockdown percentages ≥ 85%. In contrast, mosquito mortality was low. Over the study period, the absorbed dosage of permethrin averaged < 4 μg/kg/d of body weight based on measurements of three metabolites.

CONCLUSIONS

LLPI clothing retained permethrin and bioactivity against ticks after three months of use in real-world conditions. The estimated absorbed dosage of permethrin was well below the U.S. EPA level of concern, suggesting that LLPI clothing can be used safely by outdoor workers for tick bite prevention.

Students' attitudes to tick risks

INTRODUCTION AND OBJECTIVES

The ever-increasing number of patients with tick-borne diseases resulted in the presented study investigating the awareness, attitudes and knowledge among students about the threats arising from tick bites and preventive anti-tick practices.

MATERIALS AND METHOD

Questionnaires concerning these issues were distributed amongst Czech and Polish university students of science. Responses were analyzed by nationality and by gender.

RESULTS

Nearly all respondents were aware of the risks arising from ticks and could name at least one disease transmitted by ticks. The Czech students felt more threatened by tick-borne diseases, had more frequently suffered from Lyme borreliosis and were vaccinated against tick-borne encephalitis more often than the Polish students. A large number of the participants applied preventive measures against ticks in order to protect themselves. The Czech students believed in the effectiveness of repellents statistically more often than the Polish students, while effectiveness is the main criterion for selection of the right repellent in both groups.

CONCLUSION

Differences in preferences between the two nations appeared in many areas, e.g. the Czechs felt more threatened by all kind of risks and suffered from Lyme disease more frequently. Gaps can still be found in both the knowledge and behaviour among the respondents. It can be expected that the general public knowledge of this issue is rather limited in comparison with the students participating in the study, who are systematically educated in the field.

Effectiveness of Residential Acaricides to Prevent Lyme and Other Tick-borne Diseases in Humans

BACKGROUND

In the northeastern United States, tick-borne diseases are a major public health concern. In controlled studies, a single springtime application of acaricide has been shown to kill 68%-100% of ticks. Although public health authorities recommend use of acaricides to control tick populations in yards, the effectiveness of these pesticides to prevent tick bites or human tick-borne diseases is unknown.

METHODS

We conducted a 2-year, randomized, double-blinded, placebo-controlled trial among 2727 households in 3 northeastern states. Households received a single springtime barrier application of bifenthrin or water according to recommended practices. Tick drags were conducted 3-4 weeks after treatment on 10% of properties. Information on human-tick encounters and tick-borne diseases was collected through monthly surveys; reports of illness were validated by medical record review.

RESULTS

Although the abundance of questing ticks was significantly lower (63%) on acaricide-treated properties, there was no difference between treatment groups in human-tick encounters, self-reported tick-borne diseases, or medical-record-validated tick-borne diseases.

CONCLUSIONS

Used as recommended, acaricide barrier sprays do not significantly reduce the household risk of tick exposure or incidence of tick-borne disease. Measures for preventing tick-borne diseases should be evaluated against human outcomes to confirm effectiveness.

Factors Associated with Tick Bite Preventive Practices among Farmworkers in Malaysia

Background

Farmworkers are at high-risk for tick bites, which potentially transmit various tick-borne diseases. Previous studies show that personal prevention against tick bites is key, and certain factors namely, knowledge, experience of tick bites, and health beliefs influence compliance with tick bites preventive behaviour. This study aimed to assess these factors and their associations with tick bite preventive practices among Malaysian farmworkers.

Methods

A total of eight cattle, goat and sheep farms in six states in Peninsular Malaysia participated in a cross-sectional survey between August and October 2013

Results

A total of 151 (72.2%) out of 209 farmworkers answered the questionnaire. More than half of the farmworkers (n = 91) reported an experience of tick bites. Farms with monthly acaricide treatment had significantly (P<0.05) a low report of tick bites. Tick bite exposure rates did not differ significantly among field workers and administrative workers. The mean total knowledge score of ticks for the overall farmworkers was 13.6 (SD±3.2) from 20. The mean total tick bite preventive practices score for all farmworkers was 8.3 (SD±3.1) from 15. Fixed effect model showed the effects of four factors on tick bite prevention: (1) farms, (2) job categories (administrative workers vs. field workers), (3) perceived severity of tick bites, and (4) perceived barriers to tick bite prevention.

Conclusions

A high proportion of farmworkers, including administrative workers, reported an experience of tick bites. The effectiveness of monthly acaricide treatment was declared by low reports of tick bites on these farms. Tick bite preventive practices were insufficient, particularly in certain farms and for administrative workers. Our findings emphasise the need to have education programmes for all farmworkers and targeting farms with low prevention practices. Education and health programmes should increase the perception of the risk of tick bites and remove perceived barriers of tick bite prevention.

Increase in Ticks and Lyme Borreliosis, Yet Research into Its Prevention on the Wane

There is increased concern about the upward incidence of Lyme Borreliosis (LB) in Europe, the United States, Asia, and Northern Africa. However, effective measures to control tick populations or vaccines for LB are not yet available. Therefore, behavioral measures including avoidance of areas inhabited by ticks, performing routine body checks, using protective clothing, and the application of tick repellents are of great importance. Unfortunately, acceptance and uptake of many of these preventive behaviors are currently low. Hence, effective health education and public health communication aimed at promoting the uptake of preventive behaviors regarding tick bites and LB are urgently needed. In 2012, Mowbray recommended to conduct more research aimed at improving evidence-based insights regarding the promotion of preventive behaviors among the general public when exposed to the risk of LB. We fully agree with Mowbray and repeated her systematic review in May 2015 covering the period 1995-May 2015. Unfortunately, our review yielded exactly the same studies as already included in the review by Mowbray. Therefore, we again sound the alarm bell, just as Mowbray did a few years ago. As long as there are no effective measures for controlling tick populations and there is no vaccine available, we rely solely on health education and communication efforts to prevent tick bites and LB. We call on researchers and funders to prioritize research in the field of public health interventions for tick bites and LB because, in the words of Benjamin Franklin, "an ounce of prevention is worth a pound of cure."

Biomonitoring and evaluation of permethrin uptake in forestry workers using permethrin-treated tick-proof pants

We conducted a randomized case-control trial to analyze uptake of the insecticide/arcaricide permethrin in wearers of permethrin-impregnated and non-impregnated pants in German forestry. Eighty-two male workers were each equipped for a 16-week period with permethrin-treated (test group) or with non-treated work pants (control group). Pants with or without lining to protect against cuts, obtained from two different distributors, were worn in each group. Urinary permethrin metabolite levels were measured by GC-MS/MS before, during and after wearing of the pants. Permethrin uptake was calculated using additional questionnaire data. In the control group, metabolite levels in the range of environmental background exposure (median: ~0.5 μg/l) were measured. Subjects wearing impregnated pants showed consistently significantly higher exposure levels even before the first use of the pants with a maximum after 1 week of wearing the pants (median: ~12.5 μg/l). Significant differences in internal exposure were found depending on which of the distributors the pants came from. Metabolite levels decreased probably due to permethrin losses associated with laundering the pants. Calculated permethrin uptake is below the value corresponding to the WHO-proposed acceptable daily intake. Based on our data, a marginally increased cancer risk compared with the general population cannot be excluded when wearing impregnated pants over a working-lifetime period.

Epidemiology of Lyme disease among workers of forest inspectorates in Poland

INTRODUCTION

Lyme disease (Lyme borreliosis, LB) is a systemic tick-borne disease. Its symptoms include dermatological changes and systemic manifestations such as musculoskeletal, neurologic, and cardiac. The etiologic agent of LB is a spirochete known as Borrelia burgdorferi (B.b.) with rodents and small mammals as its animal reservoir. In Poland, there are approximately 9-10 cases of the disease per 100,000 inhabitants each year.

OBJECTIVE

Analyis of the incidence of Lyme borreliosis and the clinical picture of the disease among foresters.

MATERIAL AND METHODS

The research material consisted of data collected in a diagnostic survey conducted by use of a survey questionnaire method. The study involved 100 randomly selected workers of the forest inspectorate in Podkarpackie Voivodeship. Group I consisted of men between 30-45 years old with an average length of service of 14 years (48%); group II consisted of men between 45-55 years old with an average length of service of 24 years (52%).

RESULTS

Only 25% of the foresters from the first group, younger in age and with shorter service, had never been bitten by a tick, while 60% were bitten once, and 15% had been repeatedly bitten. In the second group, older in age and with longer service, only 3% had never been bitten by a tick, 35% were bitten once, while 62% had been repeatedly bitten. LB was diagnosed in 30% of the research participants from the first group and in 45% from the second group. Most frequently, LB was diagnosed as a result of the presence of erythema migrans (55%), ELISA test (20%), and Western Blot test (22%). The most frequent symptoms among the participants were: erythema migrans (45%), fever and shivers (35%), muscle pain and cramps (15%), other symptoms (5%). Permanent presence of symptoms was reported by 70% of the participants, 25% experienced symptoms periodically, and 5% only sporadically.

CONCLUSIONS

LB occurs more frequently among foresters older in age and with longer service (45%); in the younger group--30%. Despite knowledge on preventive methods, there is no effective preventive method for this disease.