Porcine proliferative enteropathy (PPE) is an infectious disease in pigs, caused by Lawsonia intracellularis (LI), affecting their intestines during growth and finishing stages, leading to higher production costs. Current detection methods for LI face two main challenges, delayed results and high costs, making them impractical for large-scale pig farming epidemiological surveys. This study developed a TaqMan-qPCR method using specific probes and primers based on the LI aspartate ammonia lyase genes from GenBank, completing detection in just 45 min. After optimizing reaction conditions, sensitivity analysis revealed that the detection limit of this method was 4.6 copies/μL targeting standard plasmids. The results of the specificity analysis showed no cross-reactivity with other common porcine pathogens, highlighting its specificity. The inter- and intra-group coefficients of variation were both <1%, indicating high reproducibility. Furthermore, the TaqMan-qPCR demonstrated 100% relative sensitivity, and a 92.50% compliance rate compared to conventional PCR, suggesting it could be a complement to the conventional PCR method. In summary, the TaqMan-qPCR method established in this study is not only suitable for epidemiological investigations and early qualitative and quantitative diagnosis of proliferative enteropathy in pigs, but it is also valuable for studying the biological characteristics of LI.

Seneca Valley virus (SVV), also referred to as Senecavirus A (SVA), is an emerging pathogen within the Picornaviridae family. Since its initial identification, SVV has been implicated in the onset of porcine idiopathic vesicular disease (PIVD) across several prominent pig-producing nations globally. Due to the clinical manifestations of SVV being challenging to differentiate from those of significant animal diseases such as foot-and-mouth disease (FMD), it poses considerable economic burdens and biosecurity challenges to the swine industry. This review endeavors to provide a comprehensive synthesis of the current state of research on SVV, systematically detailing its virological characteristics, molecular biology, global epidemiology, and evolutionary dynamics. The focus is placed on elucidating its pathogenic mechanisms in swine and the intricate molecular networks that govern its interactions with the host. Particular attention is given to the strategies employed by viral proteins to counteract host innate immune responses and to modulate autophagy, apoptosis, and other critical signaling pathways. Furthermore, we consolidate the existing diagnostic technologies and advancements in vaccine development, and we explore prospective research directions, aiming to furnish a reference for the clinical prevention and control of SVV.

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.