scholarly journals Monitoring Risk: Tick and Borrelia burgdorferi Public Participatory Surveillance in the Canadian Maritimes, 2012–2020

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1284
Author(s):  
Julie Lewis ◽  
Andrea M. Kirby ◽  
Kami Dawn Harris ◽  
Corey L. Filiaggi ◽  
Alexandra Foley-Eby ◽  
...  

Ticks are vectors of many diseases, including Lyme disease (Ld). Lyme disease is an emerging disease in Canada caused by infection with the Lyme borreliosis (Lb) members of the Borrelia genus of spirochaete bacteria, of which Borrelia burgdorferi is regionally the most prevalent. The primary tick vector in central and eastern Canada, Ixodes scapularis, is increasing in numbers and in the geographical extent of established populations. This study documents the distribution of ticks recovered by passive surveillance, and their B. burgdorferi infection prevalence, in three Canadian Maritime provinces from 2012–2020. These regions represent areas in which tick populations are widely established, establishing, and considered non-established. Using a community science approach by partnering with veterinarians and members of the public, we collected over 7000 ticks from the 3 provinces. The three species found most often on companion animals and humans were I. scapularis (76.9%), Ixodes cookei (10.4%) and Dermacentor variabilis (8.9%). The most common hosts were dogs (60.5%), cats (16.8%) and humans (17.6%). As is typical of passive surveillance tick collections, the majority of ticks recovered were adult females; for I. scapularis 90.2%, 5.3%, 3.9% and 0.6% of the total of 5630 ticks recovered for this species were adult females, adult males, nymphs and larvae, respectively. The majority of B. burgdorferi-infected ticks were I. scapularis, as expected. Borrelia infection prevalence in I scapularis was higher in Nova Scotia (20.9%), the province with the most endemic regions, than New Brunswick (14.1%) and Prince Edward Island (9.1%), provinces thought to have established and non-established tick populations, respectively. The province-wide Borrelia infection prevalence generally increased in these latter tow provinces over the course of the study. The host did not have a significant effect on B. burgdorferi infection prevalence; I. scapularis ticks from dogs, cats, humans was, 13.3% (n = 3622), 15.6% (n = 817), 17.9% (n = 730), respectively. No I. scapularis larvae were found infected (n = 33) but B. burgdorferi was detected in 14.8% of both adults (n = 5140) and nymphs (n = 215). The incidence of B. burgdorferi infection also did not differ by engorgement status 15.0% (n = 367), 15.1% (n = 3101) and 14.4% (n = 1958) of non-engorged, engorged and highly engorged ticks, respectively, were infected. In New Brunswick, at the advancing front of tick population establishment, the province-wide infection percentages generally increased over the nine-year study period and all health district regions showed increased tick recoveries and a trend of increased percentages of Borrelia-infected ticks over the course of the study. Within New Brunswick, tick recoveries but not Borrelia infection prevalence were significantly different from endemic and non-endemic regions, suggesting cryptic endemic regions existed prior to their designation as a risk area. Over the 9 years of the study, tick recoveries increased in New Brunswick, the primary study region, and I. scapularis recoveries spread northwards and along the coast, most but not all new sites of recoveries were predicted by climate-based models, indicating that ongoing tick surveillance is necessary to accurately detect all areas of risk. Comparison of tick recoveries and public health risk areas indicates a lag in identification of risk areas. Accurate and timely information on tick distribution and the incidence of Borrelia and other infections are essential for keeping the public informed of risk and to support disease prevention behaviors.

Parasitology ◽  
2016 ◽  
Vol 143 (10) ◽  
pp. 1310-1319 ◽  
Author(s):  
SANNE C. RUYTS ◽  
EVY AMPOORTER ◽  
ELENA C. COIPAN ◽  
LANDER BAETEN ◽  
DIETER HEYLEN ◽  
...  

SUMMARYLyme disease is caused by bacteria of theBorrelia burgdorferigenospecies complex and transmitted by Ixodid ticks. In North America only one pathogenic genospecies occurs, in Europe there are several. According to the dilution effect hypothesis (DEH), formulated in North America, nymphal infection prevalence (NIP) decreases with increasing host diversity since host species differ in transmission potential. We analysedBorreliainfection in nymphs from 94 forest stands in Belgium, which are part of a diversification gradient with a supposedly related increasing host diversity: from pine stands without to oak stands with a shrub layer. We expected changing tree species and forest structure to increase host diversity and decrease NIP. In contrast with the DEH, NIP did not differ between different forest types. Genospecies diversity however, and presumably also host diversity, was higher in oak than in pine stands. Infected nymphs tended to harbourBorrelia afzeliiinfection more often in pine stands whileBorrelia gariniiandBorrelia burgdorferiss. infection appeared to be more prevalent in oak stands. This has important health consequences, since the latter two cause more severe disease manifestations. We show that the DEH must be nuanced for Europe and should consider the response of multiple pathogenic genospecies.


Author(s):  
Julia E Poje ◽  
Jose F Azevedo ◽  
Nisha Nair ◽  
Kurayi Mahachi ◽  
Lexi E Frank ◽  
...  

Abstract Lyme disease, caused by Borrelia burgdorferi sensu stricto and most commonly transmitted by Ixodes scapularis Say (Ixodida: Ixodidae), is the most common tick-borne disease in Maryland. Because B. burgdorferi s.s. is maintained in enzootic cycles among wild mice (Peromyscus spp) and Ixodes spp ticks, differing patterns of parasitism of ticks on mice could impact the infection prevalence with B. burgdorferi. We determined the infection prevalence of Peromyscus spp as well as questing and partially engorged nymphal ticks collected at six sites on private land in five counties in Maryland from May to August 2020. Questing nymph infection prevalence (NIP) was 14%. We trapped 1258 mice and collected 554 ticks and 413 ear tissue samples. The prevalence of infested Peromyscus spp varied based on host age and sex, with older and male mice more likely to be infested. We detected a significant difference amongst the proportion of attached Ixodes and the location of trapping. Similarly, the prevalence of B. burgdorferi infected Peromyscus spp mice varied between locations (average mouse infection prevalence was 40%), with the highest prevalence in locations where Ixodes were the most commonly found ticks. The B. burgdorferi infection prevalence in partially engorged I. scapularis nymphs retrieved from Peromyscus spp was ~36% which lends further support to the host infection prevalence. Local differences in distribution of infected vectors and reservoirs are important factors to consider when planning interventions to reduce Lyme disease risk.


2019 ◽  
Vol 57 (1) ◽  
pp. 273-280 ◽  
Author(s):  
Alison E Simmons ◽  
Anna B Manges ◽  
Tashi Bharathan ◽  
Shannon L Tepe ◽  
Sara E McBride ◽  
...  

Abstract Lyme disease is the most commonly reported vector-borne illness and sixth most commonly reported notifiable infectious disease in the United States. The majority of cases occur in the Northeast and upper-Midwest, and the number and geographic distribution of cases is steadily increasing. The blacklegged tick (Ixodes scapularis Say) is the principal vector of the Lyme disease spirochete (Borrelia burgdorferi sensu stricto) in eastern North America. Although Lyme disease risk has been studied in residential and recreational settings across rural to urban landscapes including metropolitan areas, risk within U.S. cities has not been adequately evaluated despite the presence of natural and undeveloped public parkland where visitors could be exposed to B. burgdorferi-infected I. scapularis. We studied the occurrence of I. scapularis and infection prevalence of B. burgdorferi in four insular regional parks within the city of Pittsburgh to assess Lyme disease risk of exposure to infected adults and nymphs. We found that the density of I. scapularis adults (1.16 ± 0.21 ticks/100 m2) and nymphs (3.42 ± 0.45 ticks/100 m2), infection prevalence of B. burgdorferi in adults (51.9%) and nymphs (19.3%), and density of infected adults (0.60 ticks/100 m2) and nymphs (0.66 ticks/100 m2) are as high in these city parks as nonurban residential and recreational areas in the highly endemic coastal Northeast. These findings emphasize the need to reconsider, assess, and manage Lyme disease risk in greenspaces within cities, especially in high Lyme disease incidence states.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S342-S343
Author(s):  
Jues Koffi ◽  
Salima Gasmi

Abstract Background Lyme disease (LD) is an emerging infectious disease in Canada due to northward expansion of the geographic range of Ixodes scapularis, the principal tick vector for the LD agent Borrelia burgdorferi, into central and eastern Canada. This study aims to i) summarize the surveillance data for LD cases reported in Canada between 2009 and 2015, ii) identify potential environmental risk factors and iii) develop an acarological risk indicator from passive surveillance for occurrence of human cases. Methods We described the distribution, trends, demographic and clinical characteristics of cases of the disease. Logistic regression models were used to identify risk factors for the occurrence of LD: 1) demographic (age and sex), and 2) environmental (type of forest cover, temperature and abundance of ticks). Passive surveillance data were used to develop an acarological indicator of at-risk areas for LD. Results The number of reported LD cases increased more than six-fold overall, from 144 cases in 2009 to 917 cases in 2015, mainly due to locally acquired infections. LD incidence in Nova Scotia has risen sharply since 2013 and was the highest in Canada over the study period. Children below 15 years and adults of the 55–74 age groups reported highest incidence. Significantly more men than women were infected and men had significantly more symptoms of late disseminated LD than women. Variability in clinical manifestations is observed between provinces, years, for children below 15 years and between age groups. The majority of cases were reported between April and November and there was an increase in risk areas. The abundance of Ixodes scapularis ticks collected on humans and deciduous forest cover were significantly associated with the occurrence of LD cases at the municipality scale. Passive surveillance provides a cost-effective alert tool for public health authorities to timely identify risk areas and target vulnerable populations and front-line health professionals by means of awareness campaigns. Conclusion These findings showed that LD continues to increase in Canada, both over time and geographically, underlining the need to implement better preventive strategies, early disease recognition and treatment and efficient surveillance systems. Disclosures All authors: No reported disclosures.


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