U.S. public's experience with ticks and tick-borne diseases: Results from national HealthStyles surveys

Leveraging the Expertise of the New Jersey Mosquito Control Community to Jump Start Standardized Tick Surveillance

Despite the rising incidence of tick-borne diseases (TBD) in the northeastern United States (US), information and expertise needed to assess risk, inform the public and respond proactively is highly variable across states. Standardized and well-designed tick surveillance by trained personnel can facilitate the development of useful risk maps and help target resources, but requires nontrivial start-up costs. To address this challenge, we tested whether existing personnel in New Jersey’s 21 county mosquito control agencies could be trained and interested to participate in a one-day collection of American dog ticks (Dermacentor variabilis), a presumably widespread species never before surveyed in this state. A workshop was held offering training in basic tick biology, identification, and standard operating procedures (SOPs) for surveillance, followed by a one-day simultaneous collection of D. variabilis across the state (the “NJ Tick Blitz”). In total, 498 D. variabilis were collected from 21 counties and follow-up participant surveys demonstrated an increase in knowledge and interest in ticks: 41.7% of respondents reported collecting ticks outside the Tick Blitz. We hope that the success of this initiative may provide a template for researchers and officials in other states with tick-borne disease concerns to obtain baseline tick surveillance data by training and partnering with existing personnel.

Malaria and Lyme disease - the largest vector-borne US epidemics in the last 100 years: success and failure of public health

Malaria and Lyme disease were the largest vector-borne epidemics in recent US history. Malaria, a mosquito-borne disease with intense transmission, had higher morbidity and mortality, whereas Lyme and other tick-borne diseases are more persistent in the environment. The responses to these two epidemics were markedly different. The anti-malaria campaign involved large-scale public works eradicating the disease within two decades. In contrast, Lyme disease control and prevention focused on the individual, advocating personal protection and backyard control, with the disease incidence steeply increasing since 1980s. Control of Lyme and other tick-borne diseases will require a paradigm shift emphasizing measures to reduce tick and host (deer) populations and a substantial R&D effort. These steps will require changing the political climate, perceptions and opinions to generate support among governmental levels and the general public. Such support is essential for providing a real solution to one of the most intractable contemporary public health problems.

Trends in Multivitamin Use Among Women of Reproductive Age: United States, 2006-2016

BACKGROUND

Women of reproductive age can consume 0.4 milligrams of folic acid daily to reduce the risk of a neural tube defect (NTD)-affected pregnancy. Multivitamins (MVs) are one source of folic acid.

MATERIALS AND METHODS

Using HealthStyles survey data (n = 9268), we assessed change in prevalence of MV use during 2006-2016 among women by age (18-24, 25-34, and 35-44 years), race/ethnicity (non-Hispanic [NH] white, NH black, Hispanic), and pregnancy status (trying to get pregnant, not pregnant nor trying to get pregnant, and pregnant) using log-binomial regression.

RESULTS

Daily MV consumption decreased overall from 32.7% to 23.6% during 2006-2016 for women aged 18-44 years (p for trend <0.001). Age-specific decreases were seen in women aged 25-34 years (2006: 34.1%; 2016: 23.7%; p < 0.001) and 35-44 years (2006: 37.3%; 2016: 27.1%; p < 0.001). Decreases in daily MV intake were found among NH whites (2006: 35.4%; 2016: 24.9%; p < 0.001) and Hispanics (2006: 30.6%; 2016: 22.1%; p < 0.001), but remained unchanged among NH blacks (2006: 23.7%; 2016: 21.8%; p = 0.87). Daily MV intake remained unchanged for women trying to get pregnant (2006: 40.2%; 2012: 38.3%; p = 0.19), decreased for women not pregnant nor trying to get pregnant (2006: 31.3%; 2012: 21.3%; p < 0.001), and fluctuated for pregnant women (2006: 53.8%; 2012: 71.0%; p = 0.21). Prevalence of no MV consumption increased significantly across all age and race/ethnicity groups.

CONCLUSIONS

Overall MV intake decreased for the past decade and varied by age, race/ethnicity, and pregnancy status. Innovative messaging and targeted interventions for increasing folic acid intake are needed to reduce NTDs.

Removing the Mask of Average Treatment Effects in Chronic Lyme Disease Research Using Big Data and Subgroup Analysis

Lyme disease is caused by the bacteria borrelia burgdorferi and is spread primarily through the bite of a tick. There is considerable uncertainty in the medical community regarding the best approach to treating patients with Lyme disease who do not respond fully to short-term antibiotic therapy. These patients have persistent Lyme disease symptoms resulting from lack of treatment, under-treatment, or lack of response to their antibiotic treatment protocol. In the past, treatment trials have used small restrictive samples and relied on average treatment effects as their measure of success and produced conflicting results. To provide individualized care, clinicians need information that reflects their patient population. Today, we have the ability to analyze large data bases, including patient registries, that reflect the broader range of patients more typically seen in clinical practice. This allows us to examine treatment variation within the sample and identify groups of patients that are most responsive to treatment. Using patient-reported outcome data from the MyLymeData online patient registry, we show that sub-group analysis techniques can unmask valuable information that is hidden if averages alone are used. In our analysis, this approach revealed treatment effectiveness for up to a third of patients with Lyme disease. This study is important because it can help open the door to more individualized patient care using patient-centered outcomes and real-world evidence.

Ixodes Immune Responses Against Lyme Disease Pathogens

Although Ixodes scapularis and other related tick species are considered prolific vectors for a number of important human diseases, many aspects of their biology, microbial interactions, and immunity are largely unknown; in particular, how these ancient vectors recognize invading pathogens like Borrelia burgdorferi and influence their persistence. The analysis of the Ixodes genome and a limited set of transcriptomic data have established that ticks encode many components of classical immune pathways; yet at the same time, they lack many key orthologs of these recognition networks. Therefore, whether a given immune pathway is active in Ixodes ticks and how precisely they exert its microbicidal functions are only incompletely delineated. A few recent studies have suggested that classical pathways like the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) as well as immunodeficiency (IMD) pathways are fully functional in I. scapularis, and upon challenge with microbes, generate potent microbicidal responses against diverse tick-borne pathogens including B. burgdorferi. These studies also highlight novel concepts of vector immunity that include both a direct and an indirect mode of recognition of pathogens, as well as the influence of the gut microbiome, which ultimately dictates the outcome of a robust microbicidal response. Further understanding of how Ixodes ticks recognize and suppress invading microbes like B. burgdorferi will enrich our fundamental knowledge of vector immunobiology, thereby contributing to the development of future interventions to better control the tick-borne pathogen.

Seroprevalence of Borrelia burgdorferi in Belgian forestry workers and associated risk factors

Background

As forest is the preferred environment for ticks, forestry workers are exposed to tick bites and tick-borne diseases. We assessed the seroprevalence of anti-Borrelia burgdorferi (Bb) antibodies and investigated, using an integrated landscape approach, the individual and environmental factors associated with the seroprevalence of Bb in Belgian forestry workers, a high-risk group in Belgium.

Methods

A group of 310 Belgian forest workers was examined to assess the seroprevalence of anti-Borrelia IgG antibodies. Using principal component analysis and binary logistic regression, the joint effects of individual characteristics and environmental characteristics were examined.

Results

Sixty-seven of the 310 workers were seropositive for Lyme disease (LD), leading to a seroprevalence of 21.6%. The seroprevalence was higher among forest workers visiting forests more frequently (P = 0.003) or who reported over 100 tick bites (P-value < 0.001). The intensity of tick bites and the use of protection measures against tick bites have a positive impact on LD seroprevalence while the quantity of shadow from trees at ground level had a negative one.

Conclusions

This study showed that forest workers are a population at risk for LD and, by extension, at risk for various tick-borne diseases. In addition to the role of the environment, our results also showed the importance of considering exposure when predicting the risk of infection by Bb.

Integrated Social-Behavioral and Ecological Risk Maps to Prioritize Local Public Health Responses to Lyme Disease

BACKGROUND

The risk of contracting Lyme disease (LD) can vary spatially because of spatial heterogeneity in risk factors such as social-behavior and exposure to ecological risk factors. Integrating these risk factors to inform decision-making should therefore increase the effectiveness of mitigation interventions.

OBJECTIVES

The objective of this study was to develop an integrated social-behavioral and ecological risk-mapping approach to identify priority areas for LD interventions.

METHODS

The study was conducted in the Montérégie region of Southern Quebec, Canada, where LD is a newly endemic disease. Spatial variation in LD knowledge, risk perceptions, and behaviors in the population were measured using web survey data collected in 2012. These data were used as a proxy for the social-behavioral component of risk. Tick vector population densities were measured in the environment during field surveillance from 2007 to 2012 to provide an index of the ecological component of risk. Social-behavioral and ecological components of risk were combined with human population density to create integrated risk maps. Map predictions were validated by testing the association between high-risk areas and the current spatial distribution of human LD cases.

RESULTS

Social-behavioral and ecological components of LD risk had markedly different distributions within the study region, suggesting that both factors should be considered for locally adapted interventions. The occurrence of human LD cases in a municipality was positively associated with tick density (p<0.01) but was not significantly associated with social-behavioral risk.

CONCLUSION

This study is an applied demonstration of how integrated social-behavioral and ecological risk maps can be created to assist decision-making. Social survey data are a valuable but underutilized source of information for understanding regional variation in LD exposure, and integrating this information into risk maps provides a novel approach for prioritizing and adapting interventions to the local characteristics of target populations. https://doi.org/10.1289/EHP1943.

Smear Campaign: Misattribution of Pancytopenia to a Tick-Borne Illness

We report the case of a 51-year-old woman presenting with a targetoid rash and pancytopenia after a tick bite. Initial evaluation was notable for severe neutropenia on the complete blood cell count differential, a positive Lyme IgM antibody, and a peripheral blood smear demonstrating atypical lymphocytes. While her pancytopenia was initially attributed to tick-borne illness, peripheral flow cytometry showed 7% myeloblasts, and a bone marrow biopsy confirmed 60% blasts. The patient was ultimately diagnosed with acute myelogenous leukemia, in addition to early, localized Lyme disease. This case highlights the differential diagnosis for pancytopenia, cytopenia patterns for different tick-borne illnesses, the risk of premature closure in internal medicine, and management of Lyme disease in hosts with altered immunity.

Knowledge and preventive behaviors towards tick-borne diseases in Delaware

Delaware is among the top 10 states in the United States with the highest incidence for Lyme disease. The Delaware Division of Public Health (DPH) therefore has been working diligently to prevent and control tick-borne diseases through a variety of interventions including awareness campaigns and educational programs. To assess if tick-borne disease related information is reaching Delawareans through these programs, DPH in collaboration with Delaware State University administered an anonymous survey to 1755 participants in all three of Delaware counties during May 2017. The questionnaire assessed individuals' general knowledge about tick-borne diseases and performance of selected tick-borne disease prevention methods Overall, participants' knowledge of tick-borne diseases was poor; only 38.4% of respondents stated that ticks were problematic in Delaware and only 12.7% of respondents "strongly agreed" that Lyme disease is a problem in Delaware. A little over half of the respondents (51.6%) indicated having seen advertisements/infomercials/flyers for protection from ticks or the disease agents spread by ticks; the most common places for viewing these advertisements were doctor's offices and through social media. The reported frequency of performing preventive behaviors was variable and disparities were observed by age, race, gender and county of residence. Existing public health communication efforts on tick-borne diseases in Delaware do not appear to be having the desired effect. This study provides important baseline information to rethink communication channels for education and more effectively guide future tick-borne disease awareness campaigns.

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

Lyme disease (LD) risk is increasing in Canada. In 2014, the government of Canada launched a national communication campaign to raise awareness and promote the adoption of individual preventive behaviours toward ticks and LD. The objectives of this study were to evaluate and compare the adoption of LD preventive behaviours and the exposure to tick bites of Canadians in the five main targeted regions (British Columbia, Prairie provinces, Ontario, Quebec and the Atlantic provinces). A national survey was conducted in December 2014 (n=2876) to collect data on LD awareness, behaviours and risk factors. Overall, the proportion of respondents reporting tick exposure was high (20%). The results suggest that even though LD awareness was found to be high (with only 12% of the respondents reporting that they never heard about LD), less than half of the Canadians who heard about it have adopted specific preventive behaviours toward tick bites, such as regular tick checks (reported by 52%), protective clothing (50%), using tick repellent (41%) or shower or bath (41%) after visiting a wooded area in a LD risk area. Moreover, significant differences were found between regions, gender, age groups and dog ownership status, regarding preventive behaviours and factors of exposure. A high level of knowledge of Lyme disease, living in the Prairie region, as well as having found a tick on oneself or a relative, were found to be associated with the adoption of preventive behaviours. This study underlines the importance to take into account specific regional characteristics of risk and to maintain public health communication efforts through time in order to increase the adoption of preventive behaviours of Canadians.

Critical Evaluation of the Linkage Between Tick-Based Risk Measures and the Occurrence of Lyme Disease Cases

The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human-tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites.

Recent changes in attitudes of US adults toward people with epilepsy - Results from the 2005 SummerStyles and 2013 FallStyles surveys

OBJECTIVES

This study aimed to evaluate the validity and the reliability of two components of the Attitudes and Beliefs about Living with Epilepsy (ABLE) scale and to measure the magnitude of the public's attitudes and behaviors toward persons with epilepsy using U.S. nationally representative samples in 2005 and 2013.

METHODS

We used data from the cross-sectional 2005 SummerStyles and 2013 FallStyles surveys to test the underlying structure of 16 items of the work and role expectations and personal fear and social avoidance subscales of ABLE by performing exploratory factor analysis (EFA). We estimated the percentages and 95% confidence intervals of adults who agreed or disagreed with each item. We also calculated the mean score of each subscale and used linear regression to obtain means adjusted for selected sociodemographic characteristics.

RESULTS

Exploratory factor analysis confirmed a two-factor structure, but with the exception of omitting one item regarding work activities persons with epilepsy cannot do work activities safely, from one subscale. Both subscales also showed a high level of reliability (Cronbach's α=0.8 and Cronbach's α=0.9, respectively). Among the items in the work and role expectations subscale, a significantly higher percentage of adults in 2013 than in 2005 reported strongly or moderately agreeing that persons with epilepsy can do anything as well as anyone else (56.4%, 95% CI=54.1-58.7 vs. 47.6%, 95% CI=45.8-49.3) and can cope with everyday life (69.8%, 95% CI=67.5-72.0 vs. 55.0%, 95% CI=53.2-56.7). Among the items in the personal fear and social avoidance subscale, a significantly higher percentage of adults reported in 2013 than in 2005 strongly or moderately agreeing that they would be nervous around persons with epilepsy (25.4%, 95% CI=23.4-27.5 vs. 16.8%, 95% CI=15.4-18.2) and would avoid those with frequent seizures (12.4%, 95% CI=11.0-13.9 vs. 7.6%, 95% CI=6.7-8.7). The adjusted mean score for work and role expectations differed by sex, age, race/ethnicity, education, and income in both years. The adjusted mean score for personal fear and social avoidance differed by sex, age, race/ethnicity, education, and marital status. Negative attitudes were slightly but significantly higher in 2013 than in 2005.

CONCLUSIONS

Centers for Disease Control and Prevention's ABLE scale is a valid and reliable scale that can be used to study and to track the public's attitudes and behaviors toward persons with epilepsy. Compared with 2005, US adults' reported level of expectations for persons with epilepsy improved only in certain aspects by 2013. Adults' level of personal fear and intention for social avoidance worsened from 2005 to 2013. Because the levels of expectations and of fear and social avoidance differed by sociodemographic characteristics, continued efforts tailored to specific groups are needed. To supplement educational programs focused on improving knowledge, new communication approaches grounded in decision theory that quell risk perceptions and allay negative emotional responses are recommended.

Methods to Prevent Tick Bites and Lyme Disease

Current approaches for prevention of tick bites, Lyme disease, and other tick-borne diseases are described. Particular attention is paid to 4 risk-reduction strategies: (i) avoiding risk areas; (ii) personal protective measures that reduce the risk of tick bites or transmission of the agent of Lyme disease, Borrelia burgdorferi; (iii) reducing the number of infected ticks in the environment; and (iv) use of prophylactic antibiotic treatments following a bite to prevent clinical Lyme disease.