*4.6. Quantitative Reverse Transcription Multiplex Real-Time Polymerase Chain Reaction (RT-MRT-PCR)*

Viral RNAs were extracted using the QIAamp® Viral RNA Mini Kit (QIAGEN, Hilden, Germany). The specific RT-MRT-PCR was performed to detect and genotype CSFV as described by Huang et al. [31], who demonstrated no inter-genotypic cross-reactivity among different CSFV strains using the universal primers and specific TaqMan probes for each of the three genotypes, genotypes 1, 2, and 3. The viral loads, determined by the RT-MRT-PCR, are expressed as log viral genome copies/μL.
