The RT-LAMP primer sets used in this study have been designed by Zhang et al. (11) against ORF1a and N gene and were synthesized by Sigma-Aldrich (synthesis scale, 0.025 μmol; purification, desalt; solution, water). The sequences and the concentrations of each oligonucleotide in the 10× primer mix used for the RT-LAMP assay can be found in table S1.