A scoping review of Lyme disease research relevant to public health

Study protocol for a scoping review of Lyme disease prediction methodologies

INTRODUCTION

In the temperate world, Lyme disease (LD) is the most common vector-borne disease affecting humans. In North America, LD surveillance and research have revealed an increasing territorial expansion of hosts, bacteria and vectors that has accompanied an increasing incidence of the disease in humans. To better understand the factors driving disease spread, predictive models can use current and historical data to predict disease occurrence in populations across time and space. Various prediction methods have been used, including approaches to evaluate prediction accuracy and/or performance and a range of predictors in LD risk prediction research. With this scoping review, we aim to document the different modelling approaches including types of forecasting and/or prediction methods, predictors and approaches to evaluating model performance (eg, accuracy).

METHODS AND ANALYSIS

This scoping review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review guidelines. Electronic databases will be searched via keywords and subject headings (eg, Medical Subject Heading terms). The search will be performed in the following databases: PubMed/MEDLINE, EMBASE, CAB Abstracts, Global Health and SCOPUS. Studies reported in English or French investigating the risk of LD in humans through spatial prediction and temporal forecasting methodologies will be identified and screened. Eligibility criteria will be applied to the list of articles to identify which to retain. Two reviewers will screen titles and abstracts, followed by a full-text screening of the articles' content. Data will be extracted and charted into a standard form, synthesised and interpreted.

ETHICS AND DISSEMINATION

This scoping review is based on published literature and does not require ethics approval. Findings will be published in peer-reviewed journals and presented at scientific conferences.

Lyme borreliosis in Belgium: a cost-of-illness analysis

BACKGROUND

Lyme borreliosis (LB) is the most common tick-borne disease in Europe and North America, yet its economic burden remains largely unknown. This study aimed to estimate the economic cost associated with the different clinical manifestations of LB in Belgium.

METHODS

An incidence approach and societal perspective were used to estimate the total cost-of-illness for LB in Belgium. Costs were calculated for patients with erythema migrans (EM) or disseminated/late LB, including patients who developed post-treatment Lyme disease syndrome (PTLDS). Direct medical, direct non-medical (transportation & paid help) and indirect non-medical costs (productivity losses) were included in the analysis. Ambulatory cost data were collected through a prospective cohort study from June 2016 to March 2020, in which patients with LB were followed up 6 to 12 months after diagnosis. Hospitalization costs were retrieved from the Minimal Clinical Data registry, a mandatory registry for all Belgian hospitals, linked to the Minimal Financial Data registry. Costs were expressed in 2019 euros.

RESULTS

The total annual cost associated with clinical manifestations of LB in Belgium was estimated at €5.59 million (95% UI 3.82-7.98). Of these, €3.44 million (95% UI 2.05-5.48) or 62% was related to disseminated/late LB diagnoses and €2.15 million (95% UI 1.30-3.26) to EM. In general, direct medical costs and productivity losses accounted for 49.8% and 46.4% of the total costs, respectively, while direct non-medical costs accounted for only 3.8%. The estimated mean costs were €193 per EM patient and €5,148 per disseminated/late LB patient. While patients with PTLDS seemed to have somewhat higher costs compared to patients without PTLDS, the number of patients was too small to have representative estimates.

CONCLUSIONS

We estimate the total annual direct medical costs, direct non-medical and indirect non-medical costs associated with LB to exceed €5.5 million per year, almost evenly distributed between EM (40%) and disseminated/late LB (60%). EM costs 26 times less per patient but occurs also 16 times more frequently than disseminated/late LB. The cost burden remains limited by comparison to other infectious diseases due to the relative lower incidence.

Epizootiological aspects of natural nidality of Ixodes tick-borne borreliosis in the Moscow region (Russian Federation)

Background and Aim:

At present, tick-borne borreliosis is the most common infectious disease transmitted by ticks in Europe, Asia, and North America. This study aimed to examine the epizootiological aspects of the natural nidality of tick-borne borreliosis in Moscow region (the Russian Federation).

Materials and Methods:

A total of 2,537 ticks representing two species were collected, namely, Ixodes ricinus and Dermacentor reticulatus. The activity, number of ticks, and Borrelia infestation rates were investigated during a high season, that is, from early spring to mid-autumn.

Results:

In May, amount of I. ricinus spp. was found 2.5 times more than those representing D. reticulatus spp. (p≤0.01). In June, August, and September, the amount of I. ricinus was 9.0 (p≤0.0001), 2.0 (p≤0.05), and 5.0 times higher, respectively, compared to D. reticulatus. In the first 10 days of April, the amount of D. reticulatus was 3 times higher than that of I. ricinus (p≤0.02); in the next 10 days, their amounts were equal (p≥0.05) and in the last 10 days the amount of I. ricinus exceeded that of D. reticulatus (p≤0.05) by 1.5 times. In general, Borrelia afzelii, and Borrelia garinii, were detected. In addition, the naturally occurring tick-borne borreliosis pesthole was revealed in the Moscow region.

Conclusion:

Borrelia infection rates for ticks comprise 30%. An increase in Borrelia tick infestation was detected within the vicinity of populated areas. The amount of ticks directly depends on the temperature (20°C-25°C) and moisture (from 50%) values.

Lyme neuroborreliosis in Swedish children-PCR as a complementary diagnostic method for detection of Borrelia burgdorferi sensu lato in cerebrospinal fluid

The aim of this study was to evaluate polymerase chain reaction (PCR) as a diagnostic method for the detection of Borrelia burgdorferi s.l. in CSF of Swedish children with LNB. This study was performed retrospectively on CSF and serum samples collected from children evaluated for LNB (n = 233) and controls with other specific neurological disorders (n = 59) in a Swedish Lyme endemic area. For anti-Borrelia antibody index, the IDEIA Lyme Neuroborreliosis kit (Oxoid) was used. Two in-house real-time PCR assays targeting the 16S rRNA gene were evaluated (TaqMan® and LUX™). Among patients classified as LNB cases (n = 102), five children (5%) were Borrelia PCR-positive in CSF with the TaqMan® assay. In the Non-LNB group (n = 131), one patient was Borrelia PCR positive with the TaqMan® assay. Among controls (n = 59), all CSF samples were PCR negative. When amplifying and sequencing ospA, we found B. garinii (n = 2), B. afzelii (n = 2), B. bavariensis (n = 1), and one untypable (n = 1). With the LUX™ technology, all CSF samples were PCR negative. The TaqMan® assay could detect only few cases (n = 6) of B. burgdorferi s.l. in CSF among children with LNB and the sensitivity was very low (5%). However, using larger CSF volumes and centrifugation of samples, the PCR technique could still be useful as a complementary diagnostic method when evaluating LNB. Furthermore, detection of spirochete DNA in clinical matrices, including CSF, is the method of choice for studying epidemiological aspects of LNB, a tick-borne emerging disease.

Parenting When Children Have Lyme Disease: Fear, Frustration, Advocacy

Increasing numbers of Canadians, including children and adolescents, are being infected with Borrelia burgdorferi and contracting Lyme disease. In the present study, we provided a qualitative analysis of written correspondence produced by 23 parents of children and adolescents with Lyme disease. The goal of this study was to investigate how medical and psychological issues were highlighted by parents describing their family’s Lyme disease experiences. The results suggest a series of four stages in these families where satisfactory treatment had not been obtained over months or years. The experiences of parents evolved from feelings of worry for the child to frustration with the lack of a helpful treatment, to mistrust of physicians’ actions, and, in some case, to a rejection of the conventional health care system as a whole. Improved diagnostic testing and treatment guidelines, as well as family-centered practices of medical care were proposed as important features for improving the experiences of families living with Lyme disease.

The economic burden of Lyme disease and the cost-effectiveness of Lyme disease interventions: A scoping review

INTRODUCTION

While Lyme disease (LD) is mostly treatable, misdiagnosed or untreated LD can result in debilitating sequelae and excessive healthcare usage. The objective of this review was to characterize the body of literature on the economic burden of Lyme disease (LD) and the cost-effectiveness of LD interventions, such as antibiotic treatment and vaccination.

METHODS

We followed Joanna Briggs Institute scoping review methodologies. We systematically searched terms related to LD, economic evaluations, costs, and cost-effectiveness in Medline, Embase, PsycInfo, Cochrane Library, and the grey literature up to November 2017. We included primary economic evaluations conducted in North America and Europe, reporting LD-related costs or cost-effectiveness of human interventions. Two reviewers screened articles and charted data independently. Costs were standardized to 2017 United States dollars (USD).

RESULTS

We screened 923 articles, and included 10 cost-effectiveness analyses (CEA) and 11 cost analyses (CA). Three CEAs concluded LD vaccination was likely cost-effective only in endemic areas (probability of infection ≥1%). However, LD vaccination is not currently available as an intervention in the US or Europe. Six studies assessed economic burden from a societal perspective and estimated significant annual national economic impact of: 735,550 USD for Scotland (0.14 USD per capita, population = 5.40M), 142,562 USD in Sweden (0.014 USD per capita, 9.96M), 40.88M USD in Germany (0.51 USD per capita, 80.59M), 23.12M USD in the Netherlands (1.36 USD per capita, 17.08M), and up to 786M USD in the US (2.41 USD per capita, 326.63M).

CONCLUSIONS

Lyme disease imposes an economic burden that could be considered significant in the US and other developed countries to justify further research efforts in disease control and management. Societal costs for Lyme disease can be equally impactful as healthcare costs, but are not fully understood. Economic literature from countries with historically high incidence rates or increasing rates of Lyme disease are limited, and can be useful for future justification of resource allocation.

A scoping review of Lyme disease research relevant to public health

Lyme disease (LD) is an emerging infectious disease in Canada associated with expansion of the geographic range of the tick vector Ixodes scapularis in eastern and central Canada. A scoping review of published research was prioritized to identify and characterize the scientific evidence concerning key aspects of LD to support public health efforts. Prior to initiation of this review, an expert advisory group was surveyed to solicit insight on priority topics and scope. A pre-tested search strategy implemented in eight databases (updated September 2016) captured relevant research. Pre-tested screening and data characterization forms were completed by two independent reviewers and descriptive analysis was conducted to identify topic areas with solid evidence and knowledge gaps. Of 19,353 records screened, 2,258 relevant articles were included in the review under the following six public health focus areas: a) surveillance/monitoring in North America (n=809); b) evaluation of diagnostic tests (n=736); c) risk factors (n=545); d) public health interventions (n=205); e) public knowledge, attitudes and/or perceptions in North America (n=202); and f) the economic burden of LD or cost-benefit of interventions (n=32). The majority of research investigated Borrelia burgdorferi (n=1,664), humans (n=1,154) and Ixodes scapularis (n=459). Sufficient research was identified for potential systematic reviews in four topic areas: a) accuracy of diagnostic tests; b) risk factors for human illness; c) efficacy of LD intervention strategies; and d) prevalence and/or incidence of LD in humans or B. burgdorferi sensu stricto in vertebrate reservoirs or ticks in North America. Future primary research could focus on closing knowledge gaps, such as the role of less studied vertebrate reservoirs in the transmission cycle. Results of this scoping review can be used to quickly identify and summarize relevant research pertaining to specific questions about LD or B. burgdorferi sensu lato in humans, vertebrate hosts or vectors, providing evidence-informed information within timelines that are conducive for public health decision-making.