[Porcine Epidemic Abortion and Respiratory Syndrome (PEARS)-positive and PEARS-negative diagnoses in pig breeding and reproduction farms in The Netherlands using statistical methods].

The diagnoses Porcine Epidemic Abortion and Respiratory Syndrome (PEARS)-positive and PEARS-negative can be made using the following data on herd performance: the average number of stillborn piglets per litter, the average number of live piglets per litter and the average piglet mortality before weaning. Depending on the number of litters used in calculating the averages, the extent to which two out of the three performance data should deviate to arrive at the diagnosis PEARS-positive is given in tables and figures. The same farm will only be diagnosed PEARS-negative if after some time at least two out of the three performance data deviate less than other criteria also provided in tables and figures.