RNA Extraction-Free On-Site Diagnosis of Bovine Viral Diarrhea Virus Using a Portable PCR Device.

Bovine viral diarrhea (BVD) is a highly contagious viral disease that affects cattle, causing economic losses to the livestock industry. An effective diagnostic approach that facilitates timely decision-making is essential for the control of BVD virus (BVDV). Therefore, the development of a rapid, sensitive, and reliable assay is critical to prevent and limit the spread of the virus. Although reverse transcription real-time polymerase chain reaction (rRT-PCR) assays are widely employed for BVDV diagnosis, unavoidable delays due to sample transportation and reagent preparation can create a time window that permits further transmission of the disease. In this study, we developed an rRT-PCR assay to detect BVDV directly in bovine serum, without the need for RNA extraction, using a portable PicoGene PCR 1100 device. The newly developed BVDV assay, using an advanced BVDV detection kit, demonstrated high sensitivity by consistently detecting viral titers as low as 10² TCID₅₀/mL in serum across all three independent trials. Our findings represent a significant advancement in BVDV on-site diagnosis, achieved through the integration of the PicoGene device system with the newly developed BVDV detection assay.