Ninety-seven employees initiated the survey, however, two individuals only completed the demographic section and therefore were excluded; thus, we considered responses from 95 employees in our analysis, which corresponded to a 36.5% response rate. Sixty-five percent (61/95) of the respondents were male and 57% (54/95) were under 46 years old (18-25 years: 1%, 26-35 years: 25%, 36-45 years: 30%, and 46-65 years: 43%). The majority of respondents (74%, 70/95) had been in their current position for 10 years or more, and nearly all (98%, 93/95) reported that they worked outdoors, with 48% (46/95) working outdoors greater than 20 hours per week (Table 1). Reported job titles included foresters, civil engineers or technicians, recreation technicians, administrators, and other positions related to biology, ecology, and natural resources.
Tick Exposure. Only three respondents reported that they had not found a tick on themselves within the last two years of the survey, whereas about 76% (71/94) of respondents reported they had “frequently” found ticks on themselves within that time period; 35% (25/71) of the latter reported finding 10 or more ticks per week during peak tick season. The majority of respondents that reported frequent tick exposure reported finding ticks on themselves both at work and during outdoor recreation activities (80%, 57/71) such as hiking, gardening, camping, and hunting (Table 1, Table S5). When asked about their tick exposure while engaging in specific activities, 70% of respondents (63/91) reported that they found ticks on themselves “always” or “most of the time” while working outdoors; these individuals were categorized as reporting high tick exposure at work. Of the remaining respondents, 26% reported finding ticks “sometimes,” and 3% reported “never” finding ticks while working outdoors and were categorized as reporting low tick exposure at work (Table S5).
Disease History. Twenty-six percent (25/95) of respondents reported a history of TBD. All of these respondents reported they were diagnosed with LD by a medical provider, with 28% (7/25) of them reporting a history of LD and another TBD (Table 2). Forty-four percent (11/25) of the TBD respondents reported a single TBD diagnosis, whereas the remaining respondents reported either more than one separate diagnosis event (11/25), or possible diagnoses for coinfections (3/25). Among those who reported a history of at least one TBD diagnosis, 88% (22/25) reported that the diagnosis occurred while working at their current job, though our survey did not ask whether they thought infection was attributable to their work. Five percent of respondents (5/93) were currently being treated for a TBD at the time of the survey (Table 2).
A higher proportion of employees that had been at their job for more than 10 years reported a history of a TBD diagnosis (31% versus 12%; OR = 3.4 [0.91-12.43])); and, respondents that reported a high level of tick exposure at work were more likely to report a history of TBD diagnosis (35% versus 7%; OR = 6.7 [1.45-30.99]).
Knowledge. Sixty percent (57/95) of respondents correctly answered all True/False items (Figure 1, Table S1). All respondents (95/95) correctly answered “False” to the statements “The best way to remove an attached tick is to burn it off” and “I only have to worry about tick exposure when I’m in the woods.” The most commonly missed items were “Both ticks and mosquitoes can pass Lyme disease on to people” and “Deer are the main carriers of Lyme disease” (Figure 1). For the two multiple choice knowledge questions, the majority of respondents (59%, 56/95) correctly identified the nymph as the tick stage most likely to infect people with a TBD, whereas only 28% correctly selected summer as the season when ticks were most likely to transmit infections to humans; 66% incorrectly selected spring (Table S1).
Ninety-three percent (87/94) and 94% (89/95) of respondents correctly identified the photos of the adult female of I. scapularis and the nymph stage of I. scapularis as LD vectors, respectively (Figure 2), but only 19% (18/94) correctly identified them exclusively. The most common incorrect responses included indicating that adult females of A. americanus (54%, 51/95) transmit LD. More than half of respondents (54%, 51/95) correctly identified that the adult female of D. variabilis is not a LD vector (Figure 2).
The majority of participants (86%, 80/93) correctly selected the photo of the adult female I. scapularis as a LD vector and also responded “True” to the statement “The ticks most commonly associated with transmitting diseases to people in Wisconsin are known as black-legged ticks (also known as deer ticks; scientific name: Ixodes scapularis).” Seven percent (7/93) correctly identified the adult LD vector by name but not by photo, and 6% (6/93) correctly identified it by photo but not by name. No respondents missed both items. Of the 56 (59%) respondents who correctly answered the nymph life stage as the tick most likely to infect humans with a TBD, 95% (53/56) also selected the nymph by photo as a LD vector. Of the 38 (40%) respondents who incorrectly answered that the adult ticks were most likely to transmit a TBD to humans, 92% (35/38) still identified the nymph photo as a LD vector. Correctly, no respondents reported the larval stage ticks to be most likely to transmit TBDs to humans.
The computed knowledge scores (n = 95) had a mean of 11.6 (sd = 1.57), median of 12, and a range of 8-15. Sixty-eight percent (65/95) of respondents had a score ≥ median and were classified as HIGH KNOWLEDGE. The remaining 30 were classified as LOW KNOWLEDGE. Analyses did not reveal any statistically significant associations between knowledge level and sex, age category, years at job, hours per week worked outdoors, tick exposure, history of TBD diagnosis, TBD concern level, or practice adherence level (Table 3).
Attitudes. For 59% (56/95) of the respondents, TBDs were of HIGH CONCERN. No one indicated TBDs were “not a problem at all.” When adjusting for all other respondent factors in the multivariate model for HIGH CONCERN, respondents in the younger age category (< 46 years) were significantly less likely to be classified as HIGH CONCERN (aOR = 0.10 [0.03 – 0.41]), whereas respondents that reported working in their jobs for more than 10 years were more than 18 times more likely to be classified as HIGH CONCERN (aOR = 18.82 [4.11 – 86.17]; Table 4). Additionally, a positive association between TBD concern and adherence to protective measures was detected (aOR = 7.56 [2.20 – 26.05]; Table 4).
When asked about their likelihood of getting a hypothetical LD vaccine, 75% of the respondents (70/93) selected that they would “definitely” or be “highly likely” to get one, placing them in the HIGH VACCINE category. Eighteen percent said they would “maybe” get a vaccine (17/93), and about 6% said they would be “unlikely” or that they “would not get the vaccine” (6/93), for the LOW VACCINE category. Employees who were < 46 years old had a greater odds of being classified in the HIGH VACCINE category compared with older employees (OR = 2.63 [1.00 – 6.93]).
In general, respondents indicated that they were willing to pay $20 per year for personal protective items, such as insecticides or protective clothing, but not for community-based interventions, such as applying insecticides to the environment or modifying habitats to control tick populations (Figure 3). When given choices for the maximum amounts per year they would be willing to pay for personal tick control, the most frequent response was $50 (32%, 30/93). Twenty-five percent (23/93) reported a willingness to spend $100 or more per year; however, 12 respondents (13%) reported they would not be willing to pay any amount. By contrast, for community-level tick control efforts, the most popular response (49%, 45/92) was “not willing to pay any amount,” and 10% (9/92) reported they would be willing to pay $100 or more per year.
Women tended to be more likely to report that they would be willing to pay for personal protection items, with none of the women selecting that they would not be willing to pay for personal protections in contrast to 20% of the men, and 69% of women versus 50% of men selected that they would be willing to pay $50 or more each year (OR = 2.2 [0.89 – 5.43]). Respondents that selected maximum amounts of $50 or more for personal control items had a higher odds of being classified in the HIGH VACCINE category than respondents that selected amounts <$50 amounts (OR = 3.33 [1.14 – 10.44]).
Practices. The computed practice scores (n = 94) had a mean of 3.57 (sd = 0.78), median of 3.5, and a range of 1.5-6.0. Sixty-four percent (60/94) of respondents were classified as HIGH PRACTICE. In addition to respondents that were classified as HIGH CONCERN, respondents that reported a TBD diagnosis were more likely to be classified in the HIGH PRACTICE category ( (aOR = 5.88 [1.41 – 24.55]; Table 5). Age also was a factor that influenced practice adherence, with respondents in the older age category (≥ 46 years old) having a slightly higher odds of being in the HIGH PRACTICE group (Table 5).
When we looked at factors related to the use of specific personal protective practices in univariate models, we found that being in the younger age group (< 46 years old) was positively associated with the use of acaricides (OR= 4.49 [1.31 – 15.39]), with no statistically significant differences in other practices by age. Being classified in the high tick exposure category tended to be positively associated with “always” conducting a body check for ticks (OR= 3.0 [0.97-9.33]), and although not statistically significant, respondents that reported a TBD diagnosis also tended to be more likely to report acaricide use (OR = 5.75 [0.71 - 46.30]).
Most respondents (89%, 83/93) reported they always wear closed-toe shoes and more than half (66%, 61/93) reported they always wear long pants. About 24% and 60% of 93 respondents reported that they “always” or “occasionally” apply an acaricide (synthetic or natural), respectively, to their skin or clothing. The majority of respondents also reported that they “always” search their bodies for ticks after being outdoors at work (83%, 78/94), and no employees reported that they “never” do tick checks (Figure 4). In contrast, nearly all respondents reported that they “never” work in an acaricide-treated environment (99%, 92/93), “never” avoid woody areas (90%, 85/94), and “never” limit their time outdoors (89%, 82/94) (Figure 4).