Tissue Viral titre PCR result (ratio positivec) Serum ndd 5/5 Lung nd 5/5 Mesentery lymph node nd 3/4 Spleen nd 5/5 Belly-flank end nd 2/4 Belly-shoulder end nd 5/5 aTissues collected at necropsy within one hour after death. bFive pigs (90-95 kg) inoculated by intranasal atomization with 0.75 ml of virus stock (4 log NVSL TCID50) into each nostril. cRatio of PRRS positive samples to total completed tests. dNone detected using virus isolation technique.

Table 3: Porcine reproductive and respiratory syndrome virus in tissuesa of inoculatedb pigs.