Recent Progress in Studies of Porcine Reproductive and Respiratory Syndrome Virus 1 in China

Abstract

Due to the high incidence of PRRSV mutation and recombination, PRRSV infection is difficult to prevent and control in China and worldwide. Two species of PRRSV, Betaarterivirus suid 1 (PRRSV-1) and Betaarterivirus suid 2 (PRRSV-2), exist in China, and PRRSV-1 has always received less attention in China. However, the number of PRRSV-1 strains detected in China has increased recently. To date, PRRSV-1 has spread to more than 23 regions in China. Based on the phylogenetic analysis of ORF5 and the whole genome of PRRSV-1, Chinese PRRSV-1 can be divided into at least seven independent subgroups. Among them, BJEU06-1-like has become the mainstream subgroup in some regions of China. This subgroup of strains has a 5-aa (4 + 1) characteristic discontinuous deletion pattern at aa 357~aa 360 and aa 411 in Nsp2. Previous studies have indicated that the pathogenicity of PRRSV-1 in China is mild, but recent studies found that the pathogenicity of PRRSV-1 was enhanced in China. Therefore, the emergence of PRRSV-1 deserves attention, and the prevention and control of PRRSV-1 infection in China should be strengthened. PRRSV infection is usually prevented and controlled by a combination of virus monitoring, biosafety restrictions, herd management measures and vaccination. However, the use of PRRSV-1 vaccines is currently banned in China. Thus, we should strengthen the monitoring of PRRSV-1 and the biosafety management of pig herds in China. In this review, we summarize the prevalence of PRRSV-1 in China and clarify the genomic characteristics, pathogenicity, vaccine status, and prevention and control management system of PRRSV-1 in China. Consequently, the purpose of this review is to provide a basis for further development of prevention and control measures for PRRSV-1.

Simultaneous Detection of Porcine Respiratory Coronavirus, Porcine Reproductive and Respiratory Syndrome Virus, Swine Influenza Virus, and Pseudorabies Virus via Quadruplex One-Step RT-qPCR

“…In addition, the positive samples were selected randomly for amplification and sequencing to confirm that they were PRCoV, PRRSV, SIV, and PRV, respectively. athogens 2024, 13…”

“…PRRSV was first reported in the United States in 1987 and now has a worldwide distribution [ 12 ]. PRRSV was first reported in China in 1996, followed by widespread dissemination and rapid evolution, and both PRRSV-1 and PRRSV-2 are currently prevalent in China [ 13 , 14 ]. Continuous monitoring of PRRSV in pig herds remains an important defense and control route for this disease in China.…”

Current Status of Vaccines for Porcine Reproductive and Respiratory Syndrome: Interferon Response, Immunological Overview, and Future Prospects

“…There is limited peer-reviewed information available regarding the efficacy of MLV1 vaccines against PRRSV-2. This is largely due to PRRSV-2’s limited pathogenic role in Europe, the restriction on the use of PRRSV-1 MLV in China, and the sporadic nature of PRRSV-1 transmission in North America [ 95 , 112 ]. Although PRRSV-1 MLV vaccines have exhibited some efficacy against PRRSV-2, especially during the initial infection stages, further evidence indicates that the efficacy of MLV1 vaccines may be contingent on the challenge virus strain.…”

Tissue expression of porcine transient receptor potential mucolipin protein channels and their differential responses to porcine reproductive and respiratory syndrome virus infection in vitro

“…According to the newest official classification given by the International Committee on Taxonomy of Viruses, PRRSVs are separated into two species – Betaarterivirus suid 1 (PRRSV-1) and Betaarterivirus suid 2 (PRRSV-2) – and only 50–60% sequence similarity is noted between the two species. Strains of each species are further classified into multiple genetic lineages, and all strains are prone to sequence diversification through the accumulation of point mutations and recombination of homologous genomic fragments ( 20 ). Numerous PRRSV variants have emerged in China, including JXA1, HuN4-F112, NADC30-like and TJM-F92, which has significantly increased the complexity and difficulty of Chinese PRRSV control.…”