Active Participatory Surveillance for Early Detection of Notifiable Pathogens: A Case Study of the U.S. Swine Industry

) using the USDA Animal Disease Spread Model software (v3.5.10.0). In Phase 2, we calculated the probability of detecting ≥1 infected farm as a function of producer participation, farm-level sensitivity, farm-level prevalence, and sampling frequency. The participatory design was effective: ≥90% probability of detecting the notifiable pathogen at 0.05% farm prevalence (33 positive farms among 66,637 farms) when farm-level sensitivity was ≥20% and producer participation was ≥40%. Depending on the specimen collected, the shipment method, and the test selected, costs ranged from $0.03 to $0.07 USD (€0.02 to €0.06) per pig in inventory. Thus, a surveillance design based on collecting and testing specimens from a few targeted pigs on each of many farms would be both affordable and effective at a national level.