Agent-based modeling of raccoon rabies epidemic and its economic consequences.

摘要

In the United States, rabies strains that infect raccoons have been responsible for the largest increase animal rabies in the past 3 decades. This work includes three articles that analyze: (1) the cost of 8 distributions of oral rabies vaccine (ORV) with strains known to infect raccoons in Ohio between 1997 and 2000, (2) an agent-based simulation of uninterrupted raccoon rabies epidemic in a hypothetical area, and (3) the costs and benefits of different ORV distribution strategies.; Article 1 documents the estimated cost of implementing an ORV program to provide a more efficient use of resources to control and limit the spread of rabies. Accurately measured distribution costs can be used to perform an economic cost-benefit analysis for alternative ORV programs. The existing ORV procedure consists of distributing fishmeal bait containing ORV through various means. The cost of personnel, vehicles, and helicopter and aircraft use and other associated expenses were obtained from field records and interviews with personnel and agencies involved in the ORV program.; Article 2 examines the major characteristics and behavior of raccoon agents and their relation to their environment. Under different parameter values, the models are simulated and results of a hypothetical raccoon rabies event is obtained in terms of the rate of disease movement, shape of the epidemic front and intensity of new infections. The results indicate that model results are sensitive to certain parameters (e.g., aggressiveness of the epidemic regime, or nutrient regeneration capability of spatial units). Results on the shape of epidemic front proved to be invariant to different selection of model parameters.; In article 3, different ORV distribution strategies were devised to assess the effectiveness of ORV distribution strategies under different assumptions and their potential costs. Based on raccoon rabies literature, incidences of new infections were mapped to economic costs. These costs were used in conjunction with distribution costs obtained in Article 1 to conduct cost-benefit analyses. Results of cost-benefit analysis indicate while ORV distribution is not economically justifiable for the scope of hypothetical model space, the potential for justification of the program in a larger and real space is possible.