The effect of fluralaner treatment of small mammals on the endemic cycle of Borrelia burgdorferiin a natural environment

Among approaches aimed at reducing Lyme disease risk in the environment, those targeting reservoirs of Borrelia burgdorferiJohnson are promising because they have the potential to reduce both the density of questing Ixodes scapularisSay (Acari: Ixodidea) ticks and the prevalence of B. burgdorferiin the tick population. In this 4-yr field study, we treated a population of wild small mammals with 2 densities of fluralaner baits and investigated the effect of the treatment on 3 parameters of the endemic cycle of B. burgdorferi: (i) the prevalence of infected Peromyscusmice (PIM), (ii) the density of questing nymphs (DON), and (iii) the prevalence of infected questing nymphs (NIP). We demonstrated that fluralaner baiting is effective at reducing tick infestation of Peromyscusmice, the main reservoir of B. burgdorferiin central and northeastern North America, in the laboratory and the field. Results from this study showed a significant decrease in B. burgdorferiinfection in mice (odds ratio: 0.37 [CI95: 0.17 to 0.83]). A reduction in the DON between 45.4% [CI95: 22.4 to 61.6] and 62.7% [CI95: 45.9 to 74.2] occurred in treated area when compared with control areas. No significant effect was reported on the NIP. These results confirm the hypothesis that fluralaner baits have an effect on B. burgdorferiendemic cycle, with the potential to reduce the density of B. burgdorferi-infected ticks in the environment. Further studies performed in various habitats and public health intervention contexts are needed to refine and operationalize this approach for reducing Lyme disease risk in the environment.