Haile D G, Mount G A, Cooksey L M
Insects Affecting Man and Animals Research Laboratory, USDA-ARS, Gainesville, Florida 32604.
J Med Entomol. 1990 Jul;27(4):686-96. doi: 10.1093/jmedent/27.4.686.
Computer models were developed to simulate the effects of management technologies on populations of the American dog tick, Dermacentor variabilis (Say), principal vector of Rocky Mountain spotted fever (RMSF) in eastern North America. The technologies modeled were area-wide acaricide application, acaricide-food-baited tubes for self-treatment by small mammals, dipping of dogs in acaricides, acaricide-impregnated plastic dog collars, reduction of small mammal host populations (host management), and removal of vegetation that protects free-living tick stages (vegetative management). Submodels for each of these technologies were incorporated into a model (ADTSIM) for the population dynamics of the tick and RMSF transmission. Comparisons of simulated and observed data were used to verify reasonable accuracy of the submodels. Repetitive simulations were made to identify levels and timing of each control method (alone or combined) required to reduce tick populations below a RMSF transmission threshold of 252 unfed adults/ha. Eight to 30 acaricide applications, depending on acaricide and percentage of population treated, were needed during a 10-yr period to reduce densities of ticks below the threshold. The baited-tube method, host management, and vegetative management (depending on level and frequency of treatment) also were capable of reducing tick density below the threshold. However, acaricide-impregnated plastic dog collars did not reduce tick density below the threshold unless at least 50% of the hosts of adult ticks were domestic dogs. Integrated strategies were developed for management of ticks and RMSF in six selected states. These strategies reduced numbers of human cases of RMSF 90% or more by year 20 by maintaining tick densities between 100 and 252 unfed adults/ha.
开发了计算机模型，以模拟管理技术对美洲犬蜱（Dermacentor variabilis (Say)）种群的影响，美洲犬蜱是北美东部落基山斑疹热（RMSF）的主要传播媒介。所模拟的技术包括区域范围的杀螨剂应用、供小型哺乳动物自我治疗的杀螨剂诱饵管、狗浸泡杀螨剂、杀螨剂浸渍的塑料狗项圈、减少小型哺乳动物宿主种群（宿主管理）以及清除保护自由生活蜱阶段的植被（植被管理）。将这些技术中的每一项子模型纳入蜱虫种群动态和RMSF传播的模型（ADTSIM）中。通过比较模拟数据和观测数据来验证子模型的合理准确性。进行重复模拟，以确定将蜱虫种群减少到低于252只未进食成虫/公顷的RMSF传播阈值所需的每种控制方法（单独或组合）的水平和时机。在10年期间，根据杀螨剂和处理种群的百分比，需要进行8至30次杀螨剂应用，以将蜱虫密度降低到阈值以下。诱饵管方法、宿主管理和植被管理（取决于处理水平和频率）也能够将蜱虫密度降低到阈值以下。然而，杀螨剂浸渍的塑料狗项圈除非至少50%的成年蜱宿主是家犬，否则不会将蜱虫密度降低到阈值以下。为六个选定州制定了蜱虫和RMSF综合管理策略。到20年时，这些策略通过将蜱虫密度维持在100至252只未进食成虫/公顷之间，将人类RMSF病例数减少了90%或更多。
