Point‐of‐care diagnostic assay for rapid detection of porcine deltacoronavirus using the recombinase polymerase amplification method

Summary Porcine deltacoronavirus ( PDC oV) has emerged and spread throughout the porcine industry in many countries over the last 6 years. PDC oV caused watery diarrhoea, vomiting and dehydration in newborn piglets. A sensitive diagnostic method would be beneficial to the prevention and control of PDC oV infection. Recombinase polymerase amplification ( RPA ) is an isothermal amplification method which has been widely used for virus detection. A probe‐based reverse transcription RPA ( RT ‐ RPA ) assay was developed for real‐time detection of PDC oV. The amplification can be finished in 20 min and fluorescence monitoring was performed by a portable device. The lowest detection limit of the PDC oV RT ‐ RPA assay was 100 copies of RNA molecules per reaction; moreover, the RT ‐ RPA assay had no cross‐reaction with other common swine viruses. The clinical performance of the RT ‐ RPA assay was evaluated using 108 clinical samples (54 intestine specimens and 54 faecal swab specimens). The coincidence rate of the detection results for clinical samples between RT ‐ RPA and RT ‐ qPCR was 97.2%. In summary, the real‐time RT ‐ RPA assay offers a promising alternative to RT ‐ qPCR for point‐of‐care detection of PDC oV.