The Density of the Lyme Disease Vector, Ixodes scapularis (Blacklegged Tick), Differs Between the Champlain Valley and Green Mountains, Vermont.

Lyme disease is an emerging infectious disease of public health concern in the northeastern United States. The disease's vector, Ixodes scapularis (Say) (Blacklegged Tick), has increased its range in the past twenty years. In its newly endemic northern range there have been few studies of the Blacklegged Tick's habitat associations. From 2016-2018, we sampled for nymphal Blacklegged Ticks in the Champlain Valley and Green Mountains of Addison County, Vermont, and tested them for Borrelia burgdorferi, the Lyme disease agent. We found 10 times more ticks in the Champlain Valley than in the Green Mountains. Nymphal infection prevalence was 0.21 and did not vary by year or region. The difference in tick density reported has public health consequences, as Vermont has one of the highest rates of Lyme disease in the United States.