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The Northeast Area-wide Tick Control Project (NEATCP) was funded by the United States Department of Agriculture (USDA) as a large-scale cooperative demonstration project of the USDA-Agricultural Research Service (ARS)-patented 4-Poster tick control technology (Pound et al. 1994) involving the USDA-ARS and a consortium of universities, state agencies, and a consulting firm at research locations in the five states of Connecticut (CT), Maryland (MD), New Jersey (NJ), New York (NY), and Rhode Island (RI). The stated objective of the project was "A community-based field trial of ARS-patented tick control technology designed to reduce the risk of Lyme disease in northeastern states." Here we relate the rationale and history of the technology, a chronological listing of events leading to implementation of the project, the original protocol for selecting treatment, and control sites, and protocols for deployment of treatments, sampling, assays, data analyses, and estimates of efficacy.

The efficacy of topically treating white-tailed deer with an acaricide was evaluated in a Lyme disease-endemic community of southern New York State. Twenty-four 4-Poster feeders were placed in a 5.2 km(2) treatment area in Bedford, NY, while a site in Lewisboro, NY, 4.8 km distant, served as control. Treatment periods ran from 15 September to 15 December each fall from 1997 to 2001, and from 15 March to 15 May each spring from 1998 to 2002. Corn consumption averaged 15,779 kg in fall sessions and 9054 kg in spring sessions, and a mean of 89.6% of deer in the study area showed evidence of using the feeders. Deer densities, estimated by aerial snow counts, averaged 22 and 28 deer per km(2) in Bedford and Lewisboro, respectively, over a 3-year period. Significant reductions in tick numbers on deer captured in the treatment area were noted in fall 1999 compared to deer captured at the control site. Drag sampling for nymphal host-seeking ticks indicated 63.6% control in 2001, which dropped to 54.8% the following year, but reached 80% in 2003. Higher-than-normal acorn production in 2001 that likely caused a drop in deer visitation to the feeders may have reduced efficacy against larval ticks in 2002. The 4-Poster effectively reduced the density of Ixodes scapularis, though the level of control is dependent on environmental factors that affect feeding behavior of white-tailed deer.

In 1998, twenty-five 4-Poster deer treatment bait stations were deployed on Gibson Island (GI), Maryland, as part of the U.S. Department of Agriculture (USDA) Northeast Area-Wide Tick Control Project. Treatments concluded in June 2002, having achieved 80% and 99.5% control of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum, respectively. No area-wide tick control was attempted again on the island until 2003, when 15 Dandux-manufactured 4-Posters were purchased by the GI Corporation and operated until the present. Annual flagging at sites on the island and a similar untreated area on the nearby mainland in May and June from 1998 to 2007 has demonstrated that populations of host-seeking nymphs of both tick species have remained at consistently low levels on the island during GI Corporation administration of the 4-Posters, in spite of 40% fewer 4-Posters and increased deer density during 2003-2007.

From 1998-2002 twenty-five deer self-treatment devices (4-Posters), using 2% amitraz, were operated at three locations in Maryland to determine their effectiveness in controlling blacklegged ticks, Ixodes scapularis Say, and lone star ticks, Amblyomma americanum (L.). Each treatment site was approximately 518 ha and paired with a similar site lacking 4-Posters. Locations varied in deer density, tick abundance, and land use. Flagging for host-seeking ticks showed declines in tick populations at all treatment sites compared to control sites by the third year. By 2002, control of I. scapularis nymphs attributable to the 4-Poster intervention at the three sites was 69.0%, 75.8%, and 80%. Control of A. americanum nymphs at the two sites where they occurred was 99.5% and 95.3%. In 2003, the first posttreatment year, control of I. scapularis remained around 2001-2002 levels, but by 2004, an upward trend in nymphal numbers was detectable. Populations of A. americanum showed no increase posttreatment. These results demonstrate that control of these tick species is locally possible with 4-Poster intervention.

As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture "4-Poster" devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km(2) treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease.

The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann), against ticks using the acaricide amitraz, was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21-24 of the 4-Posters were distributed at residential sites in Old Lyme, CT, in a core treatment area of approximately 5.2 km(2) in fall 1997. The 4-Posters were active October to mid-December and March into May, corresponding to the peak periods of activity for adult Ixodes scapularis in this particular area. Corn consumption ranged from 361 to 4789 kg/month for October and November and 696-3130 kg/month during April. Usage of 4-Posters by deer generally was high (>90%), except during acorn masts in fall 1998 and 2001. Amitraz was applied by rollers at the estimated rate of 1.3 g active ingredient/ha/year. The abundance of host-seeking I. scapularis nymphs declined significantly (p < 0.001) in the core treatment area, as compared to a control community in Old Saybrook, CT, through 2004, over the project period from 1998 to 2003, from 9.3/100m(2) to 0.97/100m(2), rising to 1.90/100m(2) in 2004. From 1999 through 2003, there were 46.1%, 49.6%, 63.4%, 64.6%, and 70.2% reductions, respectively, in the nymphal tick population in comparison with the untreated community and initial tick abundance in 1998. Control of I. scapularis adults declined to only 19.1% in 2004; 2 years after the treatment of deer was discontinued. Differences in nymphal tick abundance between the control and core treatment area were significant in 1999 (p = 0.042) and highly significant in 2001 (p < 0.001) and 2002 (p = 0.002). The passive topical application to deer of the acaricide amitraz resulted in a significant decrease in the population of free-living I. scapularis nymphs in the treated core in Connecticut.

From 1997 to 2002, the U.S. Department of Agriculture's Northeast Area-wide Tick Control Project used acaricide-treated 4-Poster Deer Treatment Bait Stations in five eastern states to control ticks feeding on white-tailed deer. The objectives of this host-targeted technology were to reduce free-living blacklegged (Ixodes scapularis Say) and lone star (Amblyomma americanum [L.]) tick populations and thereby to reduce the risk of tick-borne disease. During 2002 to 2004, treatments were suspended, and tick population recovery rates were assayed. Subsequently, the major factors that influenced variations in efficacy were extrapolated to better understand and improve this technology. Treatments resulted in significant reductions in free-living populations of nymphal blacklegged ticks at six of the seven sites, and lone star ticks were significantly reduced at all three sites where they were present. During the study, maximal significant (p < or = 0.05) efficacies against nymphal blacklegged and lone star ticks at individual sites ranged from 60.0 to 81.7 and 90.9 to 99.5%, respectively. The major environmental factor that reduced efficacy was the occurrence of heavy acorn masts, which provided an alternative food resource for deer. Although the 4-Poster technology requires 1 or more years to show efficacy, this host-targeted intervention was demonstrated to be an efficacious, economical, safe, and environment-friendly alternative to area-wide spraying of acaricide to control free-living populations of these tick species.

Exotic tick species and tick-borne diseases are serious threats to live-stock, companion animals, and wildlife in the United States. Recurring introductions of exotic tick species into the United States are a significant indicator of the degree of risk. Successful tick-eradication campaigns, such as the national program that eradicated Boophilus annulatus and B. microplus from the United States, the Cattle Fever Tick Eradication Program of the US Department of Agriculture's Veterinary Services that protects against the re-entry and dissemination of Boophilus ticks from Mexico back into their former haunts in the southern states, and the eradication action that eliminated Rhipicephalus evertsi from a game park in Florida, are sources of useful information that aid in elucidating essential elements of successful eradication programs. Examples of failed eradication programs in places such as Puerto Rico and St. Croix also have heuristic value. Among the varieties of tick species and related infectious agents that threaten the United States, Boophilus ticks and bovine babesiosis, Amblyomma species (especially the tropical bont tick) and heartwater, and equine babesiosis, for which endemic vectors exist, are of special concern. Risk assessments to accumulate, evaluate, and synthesize information needed to appraise risks, consequences, and preparedness are necessary not just to inform federal, state, and local officials, as well as producers and stakeholders, but also to facilitate the creation of emergency response plans.

Deer self-treatment devices ('4-posters') were evaluated for their efficacy in reducing populations of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum. At each of three locations in Maryland, 25 '4-posters' were operated in study areas of approximately 5.18 km2. Populations of host-seeking ticks were monitored by flagging of treated areas and similar untreated control areas without '4-posters.' From 1998 to 2002 the percent mortalities achieved were 69, 75.8 and 80 at the three study sites infested with I. scapularis nymphs, and 99.5 and 95.3 for A. americanum nymphs at the two sites where this species occurred.