James H. Stark

Incidence of Lyme disease (LD) has increased over the last few decades in the United States (US). We examined trends in LD incidence and case burden in high‐incidence jurisdictions in the US from 2000 to 2021 by urbanicity. County‐level counts of confirmed LD cases from 2000 to 2021 were obtained from national surveillance data. Incidence rates were calculated using census population projections. Urbanicity was categorized using Rural–Urban Continuum Codes (RUCC). Mixed effects models were used to analyze annual changes in LD incidence. Over 70% of LD cases each year were residents of metro counties. All RUCCs had an incidence greater than 10 LD cases per 100,000 per year from 2001 to 2021. LD incidence significantly increased across all RUCCs, with the largest estimated increases in counties in moderately urban areas. Urban populations have substantially contributed to the overall burden of LD in the US, whereas populations in more moderately urban areas had the largest estimated increases in LD incidence. These findings highlight the need for targeted educational interventions and public health measures across urbanicity levels to address the rising burden of LD in the US.

Lyme borreliosis (LB) is endemic in many European countries. The prospective, epidemiological Burden of Lyme Disease (BOLD) study used unified case definitions to characterise LB burden in Europe. A retrospective case–control study was nested within the BOLD study to better understand LB risk factors. LB patients were evaluated at 14 healthcare practices in high-LB-incidence areas in six European countries: the Czech Republic, Germany, Poland, Slovakia, Slovenia, and Sweden between April 2021 and December 2022. Enrolled cases and age-group-matched controls were interviewed about potential risk factors, and multivariate regression analysis was used to analyse the responses. Patients with LB were more likely than matched controls to live in neighbourhoods with >50% woods, to have a garden that is composed of less than half dense trees, and to have a garden visited by wild animals. Characteristics associated with lower LB risk included being male and not having a bird feeder. The results are suggestive of risk associated with edge-of-the-forest areas, aligning with the previous literature on the increased risk of LB with forest fragmentation. Our findings support the importance of landscape structure and human–environment interactions in shaping LB risk.

Despite Lyme disease’s (LD) status as the most common vector borne disease in the United States, relatively little attention has been paid to the demographic characteristics of LD patients or health disparities among them. Using administrative claims for Medicare and Medicaid, two large public health insurance programs, we calculate the incidence of LD within strata of a variety of social determinants of health (SDoH) among beneficiaries living in high incidence LD states. Our findings focus principally on two critical causes of disparities, socioeconomic status and racial residential segregation. We find that distinct patterns in LD incidence exist across these strata for both Medicare and Medicaid beneficiaries who had LD between 2016 and 2021. LD rates are highest in areas with low levels of socioeconomic inequality and racial residential segregation. When positioned against other data in the literature, we argue that these findings may reflect access to health care or inadequate recognition of LD symptoms for patients from particular communities.

Up to 10% of patients with Lyme borreliosis (LB) will experience symptoms that fulfill the Infectious Disease Society of America (IDSA) criteria of post-treatment Lyme disease syndrome (PTLDS). This study assesses PTLDS in the Burden of Lyme Disease (BOLD) study through clinical assessment (“PTLDS Assessed by Clinicians”) and by post hoc evaluation of patient-reported outcomes, including the 36-Item Short Form Health Survey, Fatigue Severity Scale, and Cognitive Failures Questionnaire (“PTLDS Assessed by Questionnaire”). Among 242 LB cases who completed antibiotic treatment and had objective manifestations stabilized or resolved, 99 (40.9%) reported ≥1 symptom of fatigue, musculoskeletal pain, or cognitive impairment 10 months after diagnosis. Fifteen (6.2%) cases met the PTLDS criteria assessed by either clinicians or predefined questionnaire severity thresholds; four (1.7%) met both. PTLDS cases assessed by questionnaires and LB cases with persistent symptoms both reported greater symptom severity and poorer physical functioning than PTLDS cases assessed by clinicians. These exploratory findings suggest that clinician- and questionnaire-based assessments may identify partially different subsets of patients with PTLDS and either method could underestimate the proportion of patients with PTLDS.

Lyme borreliosis (LB) can manifest as a localized infection or, if left untreated, disseminated disease. This analysis used Patient-Reported Outcome tools to assess general health, fatigue, pain, and cognitive function in patients with localized or disseminated LB, compared with age- and site-matched controls without LB. All participants were enrolled in the Burden of Lyme Disease (BOLD) study; LB cases were assessed at 3 time points: the enrollment visit, and two follow-up visits conducted within 10 months of enrollment. Controls were evaluated at 2 time points: the enrollment contact and a follow-up contact 16–18 months post-enrollment. Symptom severity and general health quality between groups were compared using two-tailed Student’s t-tests and multivariate regression analyses. Disseminated LB cases reported greater fatigue and pain than localized LB (disseminated LB fatigue scores: 4.1, 3.7, and 3.5 at Visits 1, 2, and 3, respectively vs. localized LB: 2.9, 3.0, and 2.9; disseminated LB pain scores: 2.5, 1.6, and 1.3 vs. localized LB: 0.9, 0.6, and 0.8) and controls (fatigue score: 3.2; pain score: 1.0). Disseminated LB was also associated with reduced health-related quality of life. The results of this study indicate that health-related quality of life may vary by disease stage and that patients with disseminated disease showed persistent impairment during the acute phase and at 10-month follow-up.

Lyme borreliosis (LB), the most common European tick-borne disease, can manifest as an erythema migrans (EM) rash or as disseminated LB. The prospective Burden of Lyme Disease (BOLD) study evaluated the frequency of LB clinical manifestations, including signs, symptoms, and treatment patterns in 14 healthcare practices in endemic regions of six European countries: the Czech Republic, Germany, Poland, Slovakia, Slovenia, and Sweden. Between April 2021 and December 2022, patients with suspected LB were evaluated using predefined case definitions that were applied by investigators to identify medically attended LB cases. Enrolled cases were interviewed about their symptoms. Among the 797 LB cases, 615 (77.2%) had EM and 182 (22.8%) had disseminated disease; 154 of the disseminated cases had Lyme arthritis (LA), five had Lyme neuroborreliosis, and three had Lyme carditis. Geographically, the proportion of disseminated disease varied by country, from 1.1% in Slovenia to 78.0% in Slovakia. Overall, 76.3% of all LB cases in Slovakia were LA. Antibiotic use varied by country, although every country prescribed doxycycline. The frequency of LB manifestations varied substantially between countries. EM was the most common manifestation in all countries except Slovakia, where LA was most common. This study underscores the need for improved prevention strategies.

Background: There are an estimated 476 000 diagnosed and treated cases of Lyme disease (LD) in the United States each year. The risk of infection depends on human contact with ticks infected with Borrelia burgdorferi, typically from outdoor activities in high-incidence areas. The population prevalence of the activities that confer risk is unknown. Methods: We conducted online surveys of adults (ages 18+) and caregivers of children aged 1–17 in jurisdictions with a high incidence of LD, the states neighboring them, and selected counties in California and Oregon (CA/OR). The survey included questions on outdoor activities and occupation in forests, wooded areas, and areas with tall grass, residential characteristics, time spent in a yard, use of personal protection measures, history of LD and tick bites, and LD knowledge and risk perception. Data were weighted separately for each state-level sample and analyzed by region (ie, high incidence, neighboring, and CA/OR) and population (ie, adults and caregivers). Results: A total of 44 330 adults and 28 380 caregivers completed the survey. Most respondents were aware of LD (range, 88–93%), spent time in a yard (adults, 88–92%; children, 96%–98%), or spent recreational time outside (adults, 70–79%; children, 83–84%). Always using prevention measures while doing outdoor recreational activities was reported for 34–40% of adults and 40–42% of children. Conclusions: Despite the high population prevalence of LD awareness and of doing outdoor activities, less than half of surveyed respondents routinely used personal prevention measures to mitigate their risk of tick-borne diseases. More effective strategies and education are needed to prevent LD.