The treatment of small mammals with isoxazolines to reduce Lyme disease risk

Tuesday, November 15, 2022

4:00 PM – 4:14 PM PT

Location: Vancouver Convention Centre, Meeting Room 215/216

Presenting Author(s)

Jérôme Pelletier

Doctor in veterinary medicine
Université de Montréal
Saint-Hyacinthe, Québec, Canada

Co-author(s)

JR

Jean-Philippe Rochealeau

Cégep de Saint-Hyacinthe
Saint-Hyacinthe, Québec, Canada
CA

Cécile Aenishaenslin

Université de Montréal
Saint-Hyacinthe, Québec, Canada
NO

Nicholas Ogden

Public Health Agency of Canada
Saint-Hyacinthe, Québec, Canada
RL

Robbin Lindsay

Public Health Agency of Canada
Winnipeg, Manitoba, Canada
CB

Catherine Bouchard

Veterinary Epidemiologist
Public Health Agency of Canada
Saint-Hyacinthe, Québec, Canada
PL

Patrick A. Leighton

Professor
Université de Montréal
Saint-Hyacinthe, Québec, Canada

The development of interventions that reduce Lyme disease incidence remains a challenge. Reservoir-targeted approaches aiming to reduce tick densities or tick infection prevalence with Borrelia burgdorferi have emerged as promising ways to reduce the density of infected ticks (DIT). Acaricides of the isoxazoline family offer high potential for reducing infestation of ticks on small mammals as they have high efficacy at killing feeding ticks for a long period. Here, effectiveness of this approach was tested in a forested area in southern Quebec (Canada) known to have a high density of host-seeking B. burgdorferi-infected nymphs. Two densities of fluralaner baits (2.1 baits/1000m² and 4.4 baits/1000m²) were used during four years in forest plots. Four parameters of B. burgdorferi endemic cycle, i) infestation of small mammals by Ixodes scapularis ticks, ii) the density of host-seeking nymphs, iii) the prevalence of host-seeking B. burgdorferi-infected nymphs and iv) the prevalence of infected small mammals, were compared with control plots. The first results showed that fluralaner baiting caused a significant reduction of Peromyscus mice infestation by nymphal and larval I. scapularis ticks, a major reservoir of B. burgdorferi in central and eastern North America. Feeding of larval and nymphal I. scapularis on those species of mice is a driver of B. burgdorferi endemic cycles. It is, therefore, plausible that fluralaner baiting can have an impact on the DIT, and, then on Lyme disease risk. However, effectiveness of this approach can be mitigated by specific ecological determinants of B. burgdorferi endemic cycle.