Transmission of influenza A virus and porcine reproductive and respiratory syndrome virus using a novel nurse sow model: a proof of concept

Table 2 Porcine reproductive and respiratory syndrome virus real-time reverse transcriptase polymerase chain reaction (rRT-PCR) and virus isolation (VI) results from sows and litters before and after adoption

Days post-adoption (litter age in days)	Activities	Tests	Sow 1			Sow 2
Days post-adoption (litter age in days)	Activities	Tests	Sow serum^a	Udder wipe	Litter (POS/TOT)	Sow serum	Udder wipe	Litter (POS/TOT)
− 7 (19)	Pre-challenge PRRSV status confirmation	rRT-PCR VI	NEG NT	NEG NT	NEG NT	NEG NT	NEG NT	NEG NT
− 6 (22)	Challenge	rRT-PCR VI	NEG NT	NEG NT	NEG NT	NEG NT	NEG NT	NEG NT
− 4		rRT-PCR VI	35.81 NEG	27.13 NEG	9/9 NT	NEG NT	NEG NT	NEG NT
− 1		rRT-PCR VI	NC NC	30.4 POS	9/9 NT	NC NC	NEG NT	NC NC
0 (28)	Adoption^b	rRT-PCR VI	NC NC	NC NC	NC NC	NC NC	NC NC	NC NC
1		rRT-PCR VI	NC NC	35.05 NEG	NC^c NC	NC NC	35.15 NEG	NC NC
2		rRT-PCR VI	24.23 POS	33.28 NEG	3/11 NT	22 POS	31.06 NEG	9/9 NT
4		rRT-PCR VI	27.89 NEG	34.99 POS	6/11 NT	22.19 POS	31.84 NEG	9/9 NT
7 (32)	End of PRRSV study	rRT-PCR VI	38.58 NEG	32.58 NEG	7/11 NT	26.32 POS	34.44 POS	9/9 NT

At time of adoption litters were 28 days old.
NC not collected, NT not tested
^aNumber indicates rRT-PCR cycle threshold value.
^bNote that on adoption day and thereafter litter results correspond to the newly adopted pigs that were born to the other sow.

ISSN: 1297-9716