Porcine reproductive and respiratory syndrome virus RNA detection in
tongue tips from dead animals
Abstract
The control of porcine reproductive and respiratory syndrome virus
(PRRSV) hinges on monitoring and surveillance. The objective of this
study was to assess PRRSV RNA detection by RT-PCR in tongue tips from
dead suckling piglets compared to serum samples, processing fluids, and
family oral fluids. Tongue tips and serum samples were collected from
three PRRSV-positive breeding herd farms (farms A, B, and C) of three
different age groups: newborns (<24h), processing (2 to 7 days
of age), and weaning (18 to 22 days of age). Additionally, processing
fluids and family oral fluids were collected from 2-7 days of age and
weaning age respectively. In farms A and B, PRRSV RNA was detected in
tongue tips from all age groups (100% and 95%, respectively). In
addition, PRRSV RNA was detected in pooled serum samples (42% and
27%), processing fluids (100% and 50%), and family oral fluids (11%
and 22%). Interestingly, the average Ct value from tongue tips was
numerically lower than the average Ct value from serum samples in the
newborn age. In farm C, PRRSV RNA was only detected in serum samples
(60%) and family oral fluids (43%), both from the weaning age.
Further, no PRRSV RNA was detected in tongue tips when pooled serum
samples from the same age group tested PRRSV RNA-negative. Taken
together, these results demonstrate the potential value of tongue tips
for PRRSV monitoring and surveillance.