Rubino Francesca, Foley Patrick, Foley Janet
School of Veterinary Medicine Department of Medicine and Epidemiology, University of California, Davis, CA, USA.
Department of Biological Sciences, Sacramento State University, Sacramento, CA, USA.
Infect Dis Model. 2025 Jun 18;10(4):1179-1189. doi: 10.1016/j.idm.2025.06.005. eCollection 2025 Dec.
We explored a compartment "susceptible-infected-recovered" model to prioritize and test the effectiveness of dog- and tick-based interventions against Rocky Mountain spotted fever and its tick vector s.l. In the face of increasingly urban epidemics of RMSF with high case fatality, particularly targeting marginalized communities, wrap-around campaigns (comprising all or some of canine culling, fertility control, and restraint to property; on-dog and environmental acaricide; and education and awareness programs for public health workers and at-risk residents) are unsustainably resource-intensive and may lack efficacy in managing the very hard to control tick. Our model allows us to strategize interventions and develop an optimized campaign against RMSF, using parameters associated with the epidemic in Ensenada, Baja California as an example. Combining usage of acaricides on dogs and the environment optimized success as measured by up to 10 years of no new canine cases, a proxy for human cases, as well as reduced tick burden. Success was greater when the campaign was begun in winter or spring and achieved at least 60 % coverage. This combination was considerably more successful than either dog or environmental acaricide alone, culling of dogs which was only successful with 100 % of dogs removed, and spay/neuter campaigns which did not reduce tick burdens. However, spay/neuter of outside dogs as an adjunct to the acaricide campaign helped stabilize the canine population and encouraged herd immunity. Although parameterized for Ensenada, the model can easily be run for other communities where data on canine tick burden and tick life history traits are available, in order to tailor intervention details such as optimal timing, coverage, and re-application frequency even when public health resources are limited.
我们探索了一种“易感-感染-康复” compartment 模型，以确定针对落基山斑疹热及其蜱虫媒介（狭义）的基于犬类和蜱虫的干预措施的优先级并测试其有效性。面对病死率高的落基山斑疹热在城市中日益流行的情况，特别是针对边缘化社区，综合性防治运动（包括全部或部分犬类扑杀、生育控制以及限制犬类活动范围；犬体和环境用杀螨剂；以及针对公共卫生工作者和高危居民的教育及宣传项目）资源消耗巨大且不可持续，而且在控制极难控制的蜱虫方面可能缺乏效果。我们的模型使我们能够制定干预策略，并以墨西哥下加利福尼亚州恩塞纳达的疫情相关参数为例，制定针对落基山斑疹热的优化防治运动。将犬体和环境用杀螨剂结合使用，以长达 10 年无新犬类病例（作为人类病例的替代指标）以及蜱虫负担减轻来衡量，优化取得了成功。当防治运动在冬季或春季开始并达到至少 60%的覆盖率时，成功率更高。这种组合比单独使用犬用或环境用杀螨剂、仅在 100%的犬只被扑杀时才成功的犬类扑杀以及未减轻蜱虫负担的绝育运动要成功得多。然而，对户外犬只进行绝育作为杀螨剂防治运动的辅助措施，有助于稳定犬类种群并促进群体免疫。尽管该模型是根据恩塞纳达的参数设定的，但在有犬类蜱虫负担和蜱虫生活史特征数据的其他社区，即使公共卫生资源有限，也可以轻松运行该模型，以便调整干预细节，如最佳时机、覆盖率和重新应用频率。
