Modeling the cost of eradicating livestock-associated methicillin-resistant staphylococcus aureus in countries with a high proportion of positive herds

Due to an increased incidence of human infections, livestock-associated methicillin-resistant Staphylococcus Aureus (LA-MRSA) in pigs and its spread into the human population has been a major public and political issue in Denmark. Similar concerns are also being raised about LA-MRSA in other Western European countries. At a time when the proportion of LA-MRSA-positive pig farms was low, Norway adopted a 'trace and destroy' strategy aimed at keeping LA-MRSA out of the pig population. However, to date, no country with a high proportion of LA-MRSA-positive pig herds has chosen to use an eradication strategy. This study analyses the cost and complexities of conducting an LA-MRSA eradication program in a situation where a large proportion of herds are positive. The total cost of the eradication program was estimated based on the following components: 1) planning, 2) monitoring and testing, 3) cleaning and disinfection, 4) production gains and losses, 5) net reduction in breeding exports, and 6) loss of genetic progress, including the costs of a mitigating caesarean section strategy in breeding herds. Costs were related to the depopulation of 1 million sows, to gilt supply (as this was an important limiting factor during an eradication program in Denmark), and to aggregated losses linked to a temporary halt on breeding progress. Using conservative assumptions, the total eradication costs were estimated at €1.8 billion, broken down into: planning costs (3%), monitoring and testing (6%), cleaning and disinfection (19%), production gains and losses (33%), net loss from breeding exports (19%) and loss of genetic progress (20%). The long-term effects of an LA-MRSA eradication program for Danish pig production were uncertain and were therefore not taken into account in the analysis.