PRRS virus has been the main health concern in the pork industry for a number of years. The disease impacts herd performance both in reproduction and growth. In 1995 farmers were allowed to send in 30 blood samples to see if they had PRRS positive pigs because the virus is difficult to detect visually. 8 038 samples were collected from 286 producer units. Looking at the samples found that about 75% of the operations did not vaccinate for PRRS and about 60 percent of the units had at least one pig test positive for PRRS. In the breeding herd over half the units had at least one PRRS positive sample. The average farm had 31% of its females with PRRS positive blood, while 12% of the farms had every female infected with PRRS. For the finishing herd, the average population had over half their samples test positive for PRRS, while almost 40% of operations had all there samples test positive for PRRS.