Detection of municipalities at-risk of Lyme disease using passive surveillance of Ixodes scapularis as an early signal: A province-specific indicator in Canada

Abstract

Lyme disease, the most commonly reported vector-borne disease in North America, is caused by the spirochete Borrelia burgdorferi sensu stricto, which is transmitted by Ixodes scapularis in eastern Canada and Ixodes pacificus in western Canada. Recently, the northward range expansion of I . scapularis ticks, in south-eastern Canada, has resulted in a dramatic increase in the incidence of human Lyme disease. Detecting emerging areas of Lyme disease risk allows public health to target disease prevention efforts. We analysed passive tick surveillance data from Ontario and Manitoba to i) assess the relationship between the total numbers of I . scapularis submissions in passive surveillance from humans, and the number of human Lyme disease cases, and ii) develop province-specific acarological indicators of risk that can be used to generate surveillance-based risk maps. We also assessed associations between numbers of nymphal I . scapularis tick submissions only and Lyme disease case incidence. Using General Estimating Equation regression, the relationship between I . scapularis submissions (total numbers and numbers of nymphs only) in each census sub-division (CSD) and the number of reported Lyme disease cases was positively correlated and highly significant in the two provinces ( P ≤ 0.001). The numbers of I . scapularis submissions over five years discriminated CSDs with ≥ 3 Lyme disease cases from those with < 3 cases with high accuracy when using total numbers of tick submission (Receiver Operating Characteristics area under the curve [AUC] = 0.89) and moderate accuracy (AUC = 0.78) when using nymphal tick submissions only. In Ontario the optimal cut-off point was a total 12 tick submissions from a CSD over five years (Sensitivity = 0.82, Specificity = 0.84), while in Manitoba the cut-off point was five ticks (Sensitivity = 0.71, Specificity = 0.79) suggesting regional variability of the risk of acquiring Lyme disease from an I . scapularis bite. The performances of the acarological indicators developed in this study for Ontario and Manitoba support the ability of passive tick surveillance to provide an early signal of the existence Lyme disease risk areas in regions where ticks and the pathogens they transmit are expanding their range.

Current and Future Spatiotemporal Patterns of Lyme Disease Reporting in the Northeastern United States

“…17 Moreover, combining case reporting with tick surveillance would offer insights into local B burgdorferi transmission. 37 Our approach could help public health institutions prioritize counties…”

Evaluation of pathogen specific urinary peptides in tick-borne illnesses

“…With an estimate of 300,000 1 – 3 cases per year in the US, Lyme borreliosis is the most common vector-borne infection in North America 1 , 2 , 4 . Despite the incidence of tick-borne infections and the enormous suffering they cause, progress in accurate diagnosis and durable treatment regimens 5 – 7 has been greatly hindered by questions surrounding: (a) the cause of persistent post-treatment Lyme symptoms 4 , 8 , 9 , and (b) the prevalence and medical significance of coinfections by two or more tick-borne pathogens 10 – 12 .…”

Longitudinal study of prevalence and spatio‐temporal distribution of Borrelia burgdorferi sensu lato in ticks from three defined habitats in Latvia, 1999–2010

“…The bacteria are maintained in natural transmission cycles between reservoir hosts and ticks of the genus Ixodes . The four main vectors of human pathogenic LB genospecies are Ixodes ricinus in Europe, Ixodes persulcatus in Eastern Europe and Asia and Ixodes scapularis and Ixodes pacificus in North America (Rauter and Hartung, 2005; Geller et al ., 2013; Schillberg et al ., 2018; Gasmi et al ., 2019). Over 100 vertebrate species are speculated to be reservoir competent hosts to Borrelia (Gern et al ., 1998; Eisen and Lane, 2002; Schrauber and Ostfeld, 2002; Brisson and Dykhuizen, 2006; Hanincova et al ., 2006; Norte et al ., 2013; Heylen et al ., 2017).…”