Lyme Disease Incidence Rates Research Articles

Species Distribution Modeling of Ixodes ricinus (Linnaeus, 1758) Under Current and Future Climates, with a Special Focus on Latvia and Ukraine

This study assesses the impact of climate change on the distribution of Ixodes ricinus, which transmits Lyme disease, a growing public health concern. Utilizing ensemble models from the R package ‘flexsdm’ and climate data from WorldClim, ENVIREM, and CliMond, we project habitat suitability changes for the focus species. The models, validated against Lyme disease incidence rates, predict a 1.5-fold increase in suitable habitats in Latvia, contrasted with a 4.5-fold decrease in suitable habitats within Ukraine over the coming decades. SHAP values are analyzed to determine the most influential climatic features affecting tick distribution, providing insights for future vector control and disease prevention strategies. The optimal bioclimatic environment for I. ricinus seems to be an intricate balance of moderate temperatures, high humidity, and sufficient rainfall (bio7, 14, 18, 29). Also, radiation during the wettest quarter (bio24) significantly influences tick distribution in northern countries. This implies an increased presence of ticks in Scandinavian countries, Baltic states, etc. These findings largely coincide with our projections regarding bioclimatic suitability for ticks in Latvia and Ukraine. These shifts reflect broader patterns of vector redistribution driven by global warming, highlighting the urgent need to adapt public health planning to the evolving landscape of vector-borne diseases under climate change.

Social vulnerability and Lyme disease incidence: a regional analysis of the United States, 2000-2014


 
 Background: Lyme disease (LD), which is highly preventable communicable illness, is the most commonly reported vector borne disease in the USA. The Social Vulnerability Index (SoVI) is a county level measure of SES and vulnerability to environmental hazards or disease outbreaks, but has not yet been used in the study of LD. The purpose of this study was to determine if a relationship existed between the SoVI and LD incidence at the national level and regional division level in the United States between 2000 and 2014.
 Methods: County level LD data were downloaded from the CDC. County level SoVI were downloaded from the HVRI at the University of South Carolina and the CDC. Data were sorted into regional divisions as per the US Census Bureau and condense into three time intervals, 2000-2004, 2005-2009, and 2010-2014. QGIS was utilized to visually represent the data. Logarithmic OLS regression models were computed to determine the predictive power of the SoVI in LD incidence rates.
 Results: LD incidence was greatest in the Northeastern and upper Midwestern regions of the USA. The results of the regression analyses showed that SoVI exhibited a significant quadratic relationship with LD incidence rates at the national level.
 Conclusion: Our results showed that counties with the highest and lowest social vulnerability were at greatest risk for LD. The SoVI may be a useful risk assessment tool for public health practitioners within the context of LD control.
 

Incidence of Lyme disease in the United Kingdom and association with fatigue: A population-based, historical cohort study.

Estimations of Lyme disease incidence rates in the United Kingdom vary. There is evidence that this disease is associated with fatigue in its early stage but reports are contradictory as far as long-term fatigue is concerned. A population-based historical cohort study was conducted on patients treated in general practices contributing to IQVIA Medical Research Data: 2,130 patients with a first diagnosis of Lyme disease between 2000 and 2018 and 8,510 randomly-sampled patients matched by age, sex, and general practice, followed-up for a median time of 3 years and 8 months. Main outcome measure was time to consultation for (1) any fatigue-related symptoms or diagnosis; or (2) myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Adjusted hazard ratios (HRs) were estimated from Cox models. Average incidence rate for Lyme disease across the UK was 5.18 per 100,000 person-years, increasing from 2.55 in 2000 to 9.33 in 2018. In total, 929 events of any types of fatigue were observed, leading to an incidence rate of 307.90 per 10,000 person-years in the Lyme cohort (282 events) and 165.60 in the comparator cohort (647 events). Effect of Lyme disease on any subsequent fatigue varied by index season: adjusted HRs were the highest in autumn and winter with 3.14 (95%CI: 1.92-5.13) and 2.23 (1.21-4.11), respectively. For ME/CFS, 17 events were observed in total. Incidence rates were 11.76 per 10,000 person-years in Lyme patients (12 events) and 1.20 in comparators (5 events), corresponding to an adjusted HR of 16.95 (5.17-55.60). Effects were attenuated 6 months after diagnosis but still clearly visible. UK primary care records provided strong evidence that Lyme disease was associated with subsequent fatigue and ME/CFS. Albeit weaker on the long-term, these effects persisted beyond 6 months, suggesting patients and healthcare providers should remain alert to fatigue symptoms months to years following Lyme disease diagnosis.

The Effects of Lifestyle on the Risk of Lyme Disease in the United States: Evaluation of Market Segmentation Systems in Prevention and Control Strategies.

The aim of this study was to investigate lifestyles at risk of Lyme disease, and to geographically identify target populations/households at risk based on their lifestyle preferences. When coupled with geographically identified patient health information (e.g., incidence, diagnostics), lifestyle data provide a more solid base of information for directing public health objectives in minimizing the risk of Lyme disease and targeting populations with Lyme-disease-associated lifestyles. We used an ESRI Tapestry segmentation system that classifies U.S. neighborhoods into 67 unique segments based on their demographic and socioeconomic characteristics. These 67 segments are grouped within 14 larger “LifeModes” that have commonalities based on lifestyle and life stage. Our dataset contains variables denoting the dominant Tapestry segments within each U.S. county, along with annual Lyme disease incidence rates from 2000 through 2017, and the average incidence over these 18 years. K-means clustering was used to cluster counties based on yearly incidence rates for the years 2000–2017. We used analysis of variance (ANOVA) statistical testing to determine the association between Lyme disease incidence and LifeModes. We further determined that the LifeModes Affluent Estates, Upscale Avenues, GenXurban, and Cozy Country Living were associated with higher Lyme disease risk based on the results of analysis of means (ANOM) and Tukey’s post hoc test, indicating that one of these LifeModes is the LifeMode with the greatest Lyme disease incidence rate. We further conducted trait analysis of the high-risk LifeModes to see which traits were related to higher Lyme disease incidence. Due to the extreme regional nature of Lyme disease incidence, we carried out our national-level analysis at the regional level. Significant differences were detected in incidence rates and LifeModes in individual regions. We mapped Lyme disease incidence with associated LifeModes in the Northeast, Southeast, Midcontinent, Rocky Mountain, and Southwest regions to reflect the location-dependent nature of the relationship between lifestyle and Lyme disease.

Improving access to post-exposure prophylaxis for Lyme disease: a role for community pharmacists

Abstract Issue Virtually non-existent in Eastern Townships (ET) before 2010, Lyme disease incidence rate reached 52 confirmed cases per 100 000 in some districts in 2018, leading to post-exposure prophylaxis (PEP) recommendation by public health. To improve access to PEP, community pharmacists can now screen and initiate PEP under a collaborative practice agreement (CPA) with the regional Medical Officer of Health. Knowledge, attitudes and practices of pharmacists regarding Lyme disease PEP were surveyed after implementation of this measure. Description of the problem 312 community pharmacists practicing in ET were invited, in October 2018, to complete an online survey, based on Godin’s integrative model (2012), with questions on professional characteristics, knowledge of CPA, attitudes about PEP, and facilitators and barriers to the use of CPA. Pharmacist’s practices were evaluated using 8 clinical vignettes. Vignette-specific and a global score were calculated. Bivariate analyses were done to test the association between global score and knowledge, attitudes, facilitators and barriers. Results Response rate was 13.8%. Most pharmacists knew (97.4%) and were in favor (93.1%) of the CPA, and believed it was effective to prevent Lyme disease (96.4%). The main barriers reported to using the CPA were related to the assessment of PEP criteria. With regards to practice, pharmacists answered correctly for clients presenting all criteria for PEP (80.6%), aged < 8 y.o. (51.6%), who had their tick removed for >72 hrs (67.7%), already presenting with symptoms (32.3%) or who had exposure in a non-endemic area (38.7%). Finally, none of the variables studied were associated with the global score. Lessons This measure has now been expanded in other endemic regions in Quebec and a provincial CPA is under development. These results will help guide the development of the provincial CPA, specifically to better consider and to provide guidance regarding PEP contraindications. Key messages Pharmacist-initiated PEP is an innovative approach to increase timely population access to an essential preventive measure in the fight against Lyme disease in endemic districts. Additional guidance is required for pharmacists with regards to assessment of PEP criteria in future CPAs.

Prevalence of Lyme Disease Attributable to Military Service at the USMA, West Point NY: FY2016-2018.

Lyme disease incidence rates have steadily increased since its official recognition in 1975. Since exposure to Lyme is associated with activities conducted in and around tick-habitats including tall grass, shrubs, deciduous forest, and leaf litter, it has been suggested that service members, who are thought to spend higher amounts of time in these habitats due to training requirements, may have higher risk for exposure. Specifically, this study looks at service member and family member exposure to Ixodes scapularis, the vector for Lyme in the Northeastern and Midwestern United States. While literature pertaining to occupational and military specific exposures to Lyme vectors have attempted to quantify the possible elevated risk of Lyme disease for service members, thus far, studies have not consistently confirmed that service members are at a greater risk than family members. This cross-sectional study looks at cases of Lyme disease at Keller Army Community Hospital (KACH) on the West Point Military Reservation in New York during Fiscal Year (FY) 2016 through FY2018. Lyme cases were pulled from Military Health System Mart using current ICD-10-CM codes for Lyme related conditions (A69.20 and A69.29). In total, 144 cases were considered for the analysis. Totaling all service members and family members enrolled at KACH over the three-year period account for 35,526 person-years. Period prevalence, attributable risk percentage, population attributable risk percentage, and corresponding 95% confidence intervals were calculated for service members and family member categories. This study was conducted on human subject research according to 32CFR219 and meets the requirements of exempt status under 32CFR219.101(b)(4) because it is a cross-sectional study on existing de-identified patient data. During FY2016-2018, service members accounted for 63 cases of Lyme totaling 21,595 person-years with a period prevalence of 292 cases per 100,000 (219.8, 363.7). Family members accounted for 81 cases with a total of 13,931 person-years with a period prevalence of 581 cases per 100,000 (455.2, 707.7). The percentage of attributable risk during the three-year period credited to military status is -99.30% (-145.69%, -52.91%). The population attributable risk percentage is -43.4%. While this study was unable to capture the military specific occupational exposure to I. scapularis, it does show a difference in period prevalence between service members and family members with the family members being at higher risk to contract Lyme instead of service members as is commonly suggested in the literature. Additional studies may be conducted to see if this holds true across service member Military Occupational Specialties as a proxy for occupational exposure. Similar studies should be conducted at military installations situated in Lyme endemic areas to determine if these results are comparable across the military or specific to West Point. Future research should attempt to identify all the service member protective factors against Lyme with attribution to permethrin-treated uniforms and other military interventions designed to defend soldiers against vector-borne diseases.

Epidemiology of Lyme disease in Pennsylvania 2006–2014 using electronic health records

Lyme disease is the most common vector-borne disease in the United States. Electronic health record (EHR)-based research on Lyme disease is limited. We used Geisinger EHR data from 479,344 primary care patients in 38 Pennsylvania counties in 2006–2014 to compare EHR-based Lyme disease incidence rates to surveillance incidence rates, evaluate individual and community risk factors for incident Lyme disease, and to characterize the proportion of cases with diagnoses consistent with post-treatment Lyme disease syndrome in the EHR (PTLDSEHR). We primarily identified Lyme disease cases using diagnosis codes, serologic testing order codes, and medication orders but also completed subgroup analyses among those with positive serology and those with both diagnosis code and antibiotic treatment. We compared annual incidence rates from the EHR to surveillance by age, sex, and county. In case-control analyses, we compared cases to randomly selected controls (5:1) frequency-matched on year, age, and sex. We identified 9657 cases of Lyme disease, including 1791 cases with positive serology and 4992 cases with both diagnosis code and antibiotic treatment. Annual incidence rates in the EHR were 4.25–7.43 times higher than surveillance. In adjusted analyses, white non-Hispanic race/ethnicity (vs. black, Hispanic, or other) was associated with higher odds of Lyme disease (odds ratio [OR]: 2.06, 95% confidence interval [CI]: 1.73–2.44). Medical Assistance insurance use (always vs. never; OR: 0.77, 95% CI: 0.68–0.88), and higher community-level socioeconomic deprivation (quartile 4 vs. 1 OR: 0.50 (95% CI: 0.42–0.59) were associated with lower odds of Lyme disease. Within 4–52 weeks after Lyme disease diagnosis, 20.8% (n = 735) of cases with a diagnosis code and treatment had a diagnosis of malaise or fatigue, pain, or cognitive difficulties not present in the past 26 weeks. These results highlight the utility of EHR data for epidemiologic research on Lyme disease for case-finding, surveillance, risk factor evaluation, and characterization of PTLDS using EHR data.

Diagnostic problems of neuroborreliosis

Nowadays a significant increase in Lyme disease incidence rate in Ukraine ensures the relevance of the problem. The difficulties of clinical and laboratory diagnostics of early and late neuroborreliosis have been analyzed, the main clinical differences between the lesion of the nervous system of borrelia etiology and the similar neurological syndromes of other genesis are indicated.

Military veteran residential location and risk for Lyme disease

Some research has shown that Lyme disease cases among U.S. military veterans have increased since the early 2000s. The purpose of the present study was to determine whether high concentrations of military veterans live in areas where Lyme disease is hyper-endemic. Lyme disease case-report data for 2015 were retrieved at the county-level from the Centers for Disease Control and Prevention. Veteran population density at the county level was determined using data from the U.S. Census. County control variables, such as weather patterns, forestation, and socioeconomic conditions were retrieved from various sources. Multiple linear regression was used to examine associations between variables. After controlling for county-level environmental and social conditions, results showed that military veteran population density was positively associated with Lyme disease incidence rates. Military veterans, due to their choice of geographic residence and recreation, may be a population at risk for developing Lyme disease.

A 24-year exploratory spatial data analysis of Lyme disease incidence rate in Connecticut, USA.

Despite efforts to control Lyme disease in Connecticut, USA, it remains endemic in many towns, posing a heavy burden. We examined changes in the spatial distribution of significant spatial clusters of Lyme disease incidence rates at the town level from 1991 to 2014 as an approach for targeted interventions. Lyme disease data were grouped into four discrete time periods and incidence rates were smoothed with Empirical Bayes estimation in GeoDa. Local clustering was measured using a local indicator of spatial autocorrelation (LISA). Elliptic spatial scan statistics (SSS) in different shapes and directions were also performed in SaTScan. The accuracy of these two cluster detection methods was assessed and compared for sensitivity, specificity, and overall accuracy. There was significant clustering during each period and significant clusters persisted predominantly in western and eastern parts of the state. Generally, the SSS method was more sensitive, while LISA was more specific with higher overall accuracy in identifying clusters. Even though the location of clusters changed over time, some towns were persistently (across all four periods) identified as clusters in LISA and their neighbouring towns (three of four periods) in SSS suggesting these regions should be prioritized for targeted interventions.

Studies on Lyme disease incidence rates in selected groups of forestry workers in West Pomerania, 2005-2014

The data collected by sanitary-epidemiological stations in 2005-2014 were analyzed to determine the incidence rates of borreliosis Lyme disease in the West Pomerania group of workers exposed to tick bites. It was assumed that an adequate comparison of official epidemiological data with the data concerning the number of exposed people, is an indispensable condition for assessing properly the trend in Lyme disease incidence rates, concerning at the same time a real scale of occupational exposure. The study covered a selected group of forestry workers, i.e., white-collar staff employed in different units of the State Forests National Forest Holding with their seats in West Pomerania. The aim of the research was to process and analyze the data on workers employed in the forest sector and their positions, requested from district sanitary-epidemiological stations. In the years concerned 282 cases of the occupational disease were recorded mainly in the groups of forest rangers, junior foresters and forest service inspectors. The values of the incidence factor exhibit high variability with the major share of cases recorded in the years 2008-2010 that accounted for 61.8% of the total occurrences concerned. The incidence in the years 2008, 2009 and 2010 amounted to 2418, 2828 and 2646 cases per 100 000 employees, respectively. The results show that previously published information about the incidence of Lyme disease in the agriculture, forestry and hunting sector, did not fully illustrate a real scale of occupational risk. Med Pr 2017;68(2):211-220.

An Examination of the Demographic and Environmental Variables Correlated with Lyme Disease Emergence in Virginia.

Lyme disease is the United States' most significant vector-borne illness. Virginia, on the southern edge of the disease's currently expanding range, has experienced an increase in Lyme disease both spatially and temporally, with steadily increasing rates over the past decade and disease spread from the northern to the southwestern part of the state. This study used a Geographic Information System and a spatial Poisson regression model to examine correlations between demographic and land cover variables, and human Lyme disease from 2006 to 2010 in Virginia. Analysis indicated that herbaceous land cover is positively correlated with Lyme disease incidence rates. Areas with greater interspersion between herbaceous and forested land were also positively correlated with incidence rates. In addition, income and age were positively correlated with incidence rates. Levels of development, interspersion of herbaceous and developed land, and population density were negatively correlated with incidence rates. Abundance of forest fragments less than 2 hectares in area was not significantly correlated. Our results support some findings of previous studies on ecological variables and Lyme disease in endemic areas, but other results have not been found in previous studies, highlighting the potential contribution of new variables as Lyme disease continues to emerge southward.

Effects of Reduced Deer Density on the Abundance ofIxodes scapularis(Acari: Ixodidae) and Lyme Disease Incidence in a Northern New Jersey Endemic Area

We monitored the abundance of Ixodes scapularis Say (Acari: Ixodidae) and the Lyme disease incidence rate after the incremental removal of white-tailed deer, Odocoileus virginianus Zimmermann, within a suburban residential area to determine whether there was a measurable decrease in the abundance of ticks due to deer removal and whether the reduction in ticks resulted in a reduction in the incidence rate within the human population. After three seasons, the estimated deer population was reduced by 46.7%, from the 2002 postfawning estimate of 2,899 deer (45.6 deer per km2) to a 2005 estimate of 1,540 deer (24.3 deer per km2). There was no apparent effect of the deer culling program on numbers of questing I. scapularis subadults in the culling areas, and the overall numbers of host-seeking ticks in the culling areas seemed to increase in the second year of the program. The Lyme disease incidence rate generated by both passive and active surveillance systems showed no clear trend among years, and it did not seem to vary with declining deer density. Given the resources required to mount and maintain a community-based program of sufficient magnitude to effectively reduce vector tick density in ecologically open situations where there are few impediments to deer movement, it may be that deer reduction, although serving other community goals, is unlikely to be a primary means of tick control by itself. However, in concert with other tick control interventions, such programs may provide one aspect of a successful community effort to reduce the abundance of vector ticks.

Effects of Reduced Deer Density on the Abundance of <I>Ixodes scapularis</I> (Acari: Ixodidae) and Lyme Disease Incidence in a Northern New Jersey Endemic Area

We monitored the abundance of Ixodes scapularis Say (Acari: Ixodidae) and the Lyme disease incidence rate after the incremental removal of white-tailed deer, Odocoileus virginianus Zimmermann, within a suburban residential area to determine whether there was a measurable decrease in the abundance of ticks due to deer removal and whether the reduction in ticks resulted in a reduction in the incidence rate within the human population. After three seasons, the estimated deer population was reduced by 46.7%, from the 2002 postfawning estimate of 2,899 deer (45.6 deer per km2) to a 2005 estimate of 1,540 deer (24.3 deer per km2). There was no apparent effect of the deer culling program on numbers of questing I. scapularis subadults in the culling areas, and the overall numbers of host-seeking ticks in the culling areas seemed to increase in the second year of the program. The Lyme disease incidence rate generated by both passive and active surveillance systems showed no clear trend among years, and it did not seem to vary with declining deer density. Given the resources required to mount and maintain a community-based program of sufficient magnitude to effectively reduce vector tick density in ecologically open situations where there are few impediments to deer movement, it may be that deer reduction, although serving other community goals, is unlikely to be a primary means of tick control by itself. However, in concert with other tick control interventions, such programs may provide one aspect of a successful community effort to reduce the abundance of vector ticks.

A comparison of analysis units for associating Lyme disease with forest-edge habitat

The rational definition of spatial analysis units is critical to modeling and understanding large-scale ecological processes. This study assessed the relationship between forest-edge habitat pattern and Lyme disease incidence rate when modeled under three designs for spatial data aggregation. Incidence rates were calculated from passive surveillance data reported for 12 counties in the U.S. State of Maryland during 1996–2000. A design using road-bounded polygons that varied in size from 0.002 km 2 to 368 km 2 ( n = 415) was compared with designs that used grid cells of 10 km 2 ( n = 823) and 36 km 2 ( n = 230). Major roads were chosen to approximate bounded populations of deer and humans engaged in outdoor activity around the home (peridomestic activity). While cell boundaries were arbitrary, cell sizes were chosen to eliminate outliers observed in small polygons, and to standardize the presumed zone of exposure. The single variable that explained the most variation in incidence rate across all study desi...

Towards landscape design guidelines for reducing Lyme disease risk

Incidence of Lyme disease in the US continues to grow. Low-density development is also increasing in endemic regions, raising questions about the relationship between development pattern and disease. This study sought to model Lyme disease incidence rate using quantitative, practical metrics of regional landscape pattern. The objective was to progress towards the development of design guidelines that may help minimize known threats to human and environmental health. Ecological analysis was used to accommodate the integral landscape variables under study. Case data derived from passive surveillance reports across 12 counties in the US state of Maryland during 1996-2000; 2,137 cases were spatially referenced to residential addresses. Major roads were used to delineate 514 landscape analysis units from 0.002 to 580 km(2). The parameter that explained the most variation in incidence rate was the percentage of land-cover edge represented by the adjacency of forest and herbaceous cover [R(2) = 0.75; rate ratio = 1.34 (1.26-1.43); P < 0.0001]. Also highly significant was the percentage of the landscape in forest cover (cumulative R(2) = 0.82), which exhibited a quadratic relationship with incidence rate. Modelled relationships applied throughout the range of landscape sizes. Results begin to provide quantitative landscape design parameters for reducing casual peridomestic contact with tick and host habitat. The final model suggests that clustered forest and herbaceous cover, as opposed to high forest-herbaceous interspersion, would minimize Lyme disease risk in low-density residential areas. Higher-density development that precludes a large percentage of forest-herbaceous edge would also limit exposure.

The Geographic Spread and Temporal Increase of the Lyme Disease Epidemic

To describe the temporal and geographic progression of the Lyme disease epidemic in New York State from 1977 through 1989. Communicable disease surveillance system. Statewide. The progression of the epidemic was examined by analyzing trends in Lyme disease cases reported to the state surveillance system, town and county Lyme disease incidence rates, Lyme disease hospital discharge rates, and the distribution of Ixodes dammini ticks obtained from surveillance efforts and submitted for identification. The number of confirmed Lyme disease cases in New York has increased with concurrent increases in the number of hospital discharges. The number of counties endemic for Lyme disease increased from four to eight between 1985 and 1989. The number of counties with documented I dammini ticks increased from four in 1985 to 22 in 1989. Incidence of the disease also increased within known endemic counties. Tick surveillance indicated that the range of I dammini has expanded annually into areas up to 384 km from the original known endemic areas of Long Island, NY, and Connecticut. Cumulative data from human surveillance resources document both temporal increases and geographic expansion of the Lyme disease epidemic in New York.