Peridomestic prevention of Lyme and other tick-borne diseases using an integrated tick management approach

Studies evaluating single-tactic peridomestic tick control measures have shown applying synthetic pyrethroids can effectively suppress nymphal blacklegged tick populations, and using rodent-targeted bait boxes can similarly reduce tick densities and impact nymphal tick infection rates. While effective at reducing acarological risk factors, neither single approach, however, has been shown to reduce incidence of Lyme and other blacklegged tick-associated diseases in humans. We conducted a prospective, placebo-controlled study to evaluate an integrated tick management (ITM) approach for reducing acarologic risk, risk for human-tick encounters, and risk for tick-borne illness. We enrolled 132 households in western Connecticut and southern Rhode Island, whose properties were treated with an ITM approach (beta-cyfluthrin spray and rodent-targeted tick control bait boxes) or placebo (water spray and inactive bait boxes). Compared to placebo properties, nymphal tick densities were reduced by 60-89% along the forested edges (where lawn meets woods) of treated properties after one year of treatment, and by 62-87% along forested edges of treatment properties after two years of treatment. Nymphal tick densities were not similarly reduced in deeply forested areas located >13 m away from treated edges. The rates of nymphal infection with Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, and Borrelia miyamotoi were not significantly different at treatment sites compared to placebo sites. Overall, the ITM approach used in this study impacted tick densities only at forested edges of properties that received beta-cyfluthrin, and did not impact tick pathogen prevalence, rates of human-tick encounters, or incidence of tick-borne diseases.