While the models may seem complex, they effectively deal with a complex interaction of biology and economics. “Biosecurity program costs accrue each year but outbreaks happen only occasionally, so in years where no disease would be introduced, the most economical plan would be to spend no money on biosecurity” Sanderson says. “But in years when disease is introduced and an outbreak occurs, the losses can exceed many years of biosecurity program costs. The problem is how to assess the frequency of outbreaks, the cost of outbreaks, and the effectiveness of various control strategies.”
Sanderson says much data are available on BVDV and trich in the scientific literature and was utilized in the models. “For a variety of reasons we cannot directly collect the data on the interaction of all of these management and risk issues,” he says. “Imagine enrolling 200+ herds in a clinical trial and randomly imposing import practices and biosecurity practices on them — the cost would be prohibitive both in dollars and in angry ranchers. So risk analysis simulation modeling is a way to capture this as best we can and make better decisions based on what pays best or minimizes loss in the long run.”
Risk assessment tools
To access the BVDV and trich risk-assessment tools, visit the Kansas State Production Medicine Page.