Pork producers face many different challenges to the health of their pigs, and PRRS (porcine reproductive and respiratory syndrome) is one of such challenges. PRRS emerged in the US for the first time 25 years ago and has since become the most costly disease of pigs with estimated annual losses of $664 million. The Swine Health Committee of the National Pork Board has committed to more than $11 million to research on PRRS to help better control and manage this disease and to reduce producer losses. To assist the Swine Health Committee to determine the value of PRRS research and the return on investment of Checkoff dollars, a comprehensive literature review has been conducted to update current knowledge for ‘PRRS Virology’ and to apply this information to future research priority and goals that may be funded by National Pork Board. Of more than 2,000 scientific articles published on PRRS as of June 2014, approximately 400 articles relevant to ‘PRRS Virology’ have been referred to prepare this report. This review is organized to describe five main topics on PRRS virology; 1) virion proteins and viral replication, 2) cellular receptors for PRRSV infection, 3) viral modulation of host immunity, 4) PRRSV reverse genetics and application of infectious clones, and 5) evolution and diversification of PRRSV. The viral capacity for innate immune suppression may be linked to inadequate elimination of the virus and persistence in infected pigs. The genetic technology to modify viral genome has become available for PRRSV and has been used for development of better vaccine candidates and also for study of the virus. The cellular receptor is known for PRRSV and tremendous advances have been made on the cell virus interactions. Some key knowledge gaps have been identified and this report should be useful not only for the National Pork Board but for the swine research community and other stakeholders.
Contact information: Dr. Dongwan Yoo, Professor of Virology, Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana IL; Email: [email protected]; Phone: 217-244-9120.