Submitted to: Vector-Borne and Zoonotic Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/9/2009
Publication Date: 8/4/2009
Citation: Brei, B., Brownstein, J.S., George, J.E., Pound, J.M., Miller, J.A., Daniels, T., Falco, R.C., Stafford, K.C., Schulze, T.L., Mather, T.N., Carroll, J.F., Fish, D. 2009. Evaluation of the USDA Northeast Area-wide Tick Control Project by Meta-analysis. Vector-Borne and Zoonotic Diseases. 9:423-430. Interpretive Summary: Blacklegged ticks (deer ticks) are the principal vectors of the pathogen causing Lyme disease and lone star ticks are associated with the transmission of monocytic ehrlichiosis. The efficacy of ‘4-poster’ deer self-treatment devices, developed by researchers at the USDA, ARS Knipling-Bushland U. S. Livestock Insects Research Laboratory , Kerrville, TX, was tested in field trials at locations in five states. Populations of blacklegged ticks were reduced at the ‘4-poster’ sites (each 2 square miles in area) during the USDA Northeast Tick Control Project (1998-2002). An overall analysis of the data collected from the five sites showed that the ‘4-poster’ lowered the density of nymphal blacklegged ticks 71%. These findings are of interest to researcher, public health officials and the general public living or working in areas where Lyme disease is prevalent. The ‘4-poster’ technology is now commercially available.
Technical Abstract: 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 USDA ‘4-Poster’ devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis, and, in some states Amblyomma americanum, 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 Ixodes 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 5.14km2 treatment sites, corresponding to a 71% lower relative entomological risk index for acquiring Lyme disease.