Research Progress on Diagnostic Technologies for Major Swine Reproductive Viral Diseases

Viral diseases that cause swine reproductive disorders pose severe threats to the global pig industry and result in enormous economic losses worldwide. The high similarity of clinical symptoms, widespread co-infections, and continuous emergence of novel pathogens urgently require rapid and accurate diagnostic strategies to support efficient disease prevention and control. This narrative review summarizes and analyzes the latest advances in diagnostic technologies for major swine reproductive viral pathogens, including Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), Classical Swine Fever Virus (CSFV), Porcine Circovirus (PCV), Pseudorabies Virus (PRV), and Porcine Parvovirus (PPV). We mainly focus on state-of-the-art diagnostic approaches centered on nucleic acid detection and serological identification. In terms of nucleic acid detection, this review elaborates on the technological evolution from conventional Polymerase Chain Reaction (PCR) to real-time quantitative PCR (qPCR) and digital PCR (dPCR), highlighting the critical value of multiplex PCR (mPCR) in differential diagnosis of swine viral diseases. Meanwhile, we summarize widely applicable isothermal amplification techniques, including Loop-Mediated Isothermal Amplification (LAMP) and Recombinase Polymerase Amplification (RPA)/Recombinase-Aided Amplification (RAA), which are highly suitable for point-of-care testing (POCT). Emerging CRISPR-Cas-based diagnostic systems for swine viral detection are also comprehensively discussed. Regarding serological detection, this article systematically reviews diverse Enzyme-Linked Immunosorbent Assay (ELISA) methods and their practical applications in serological antibody monitoring and the Differentiating Infected from Vaccinated Animals (DIVA) strategy. Furthermore, the potential application of Lateral Flow Immunoassay (LFIA) in rapid on-site screening is evaluated. This review aims to provide a comprehensive and up-to-date theoretical reference for the precise prevention and targeted control of swine reproductive viral diseases.