Viral load detection in serum, saliva, nasal and rectal swabs, and tissue samples

(A–D) Porcine reproductive and respiratory syndrome virus (PRRSV) RNA detection in serum, saliva, nasal, and rectal swabs from 8-week-old piglets after PRRSV infection using Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR). Different letters indicate significant statistical differences (p < 0.05) between groups: intramuscular (IM) vs intranasal (IN) (a), IM vs Control (C) (b), and IN vs C (c). (E) Titration of PCR and virus isolation-positive serum samples in PAM-KNU cells. (F) PRRSV RNA detection in different tissues from pigs in each experimental group using RT-qPCR. Data are presented as mean ± SD.