Can tongue tips from dead piglets be used for PRRSV surveillance?

Problem: PRRSV surveillance requires practical and sensitive samples, but individual sampling can be labor-intensive and available population-based samples vary with pig age and farm practices.

Methods: In three PRRSV-positive breeding herds, tongue tips from dead piglets were compared by RT-qPCR with pooled serum and, depending on age, processing fluids and family oral fluids in newborn, processing-age and weaning-age piglets.

Takeaway 1: On farms A and B, 100% and 95.2% of tongue-tip samples were PRRSV-positive, compared with 42.1% and 27.5% of pooled serum samples.

Takeaway 2: On farm C, all tongue-tip samples were negative while PRRSV was detected in serum and family oral fluids at weaning; no tongue-tip samples were positive when pooled serum from the same age group was negative.

Takeaway 3: Tongue tips from dead piglets are a potentially practical population sample, but evidence from only three farms does not support claiming universal superiority over serum.