Research Projects

PCVAD Risk-Assessment Matrix

Establishment of a Risk-Assessment Matrix for Porcine circovirus-associated diseases (PCVAD)

Porcine circovirus-associated diseases (PCVAD) have a devastating economic impact on the swine industry worldwide, causing costs exceeding several billions of dollars every year. Curtailing porcine circovirus (PCV) 2 infections is among the top priorities for the Canadian pork industry and has been targeted by strategic industry initiatives developed by the Canadian Swine Health Board and PigGen Canada. Vaccination against PCV2 significantly reduces the morbidity and mortality of PCVAD, greatly increases the growth performance of pigs and decreases the financial losses associated with PCV2 infection. However, current PCV2 vaccines do not appear to reproducibly induce protective levels of neutralizing antibodies and do not prevent infection. Thus, vaccines available to producers and veterinarians for managing PCV2 are somewhat limited in effectiveness.

Several possible factors contribute to the clinical expression of PCVAD, one essential of these factors is the infection with PCV2. A comprehensive investigation under field conditions which integrates the effects of host genetic background, PCV2 strains, concomitant infections and age on the production of protective immunity in both vaccinated and naturally infected pigs is required not only to understand the pathogenesis of PCVAD but also to assess the relative level of risk each farm will face during a large-scale PCV2 outbreak. We hypothesize that establishing a PMWS risk-assessment matrix is of pivotal importance to curb the spread of this disease by improving farm management practices, developing better breeding programs and producing novel vaccines.

This project will accommodate a comprehensive investigation on the nature of the humoral immune response of pigs against PCV2 under field conditions. We will perform a broad serological survey on historic and current pig sera to 1) determine the prevalence and relevance of neutralizing antibodies titers with respect to age, PCV2 infection (clinical vs. sub-clinical), disease outcome, vaccination status and genetic background and 2) assess if swine sera with high PCV2-NA titers recognize previously identified neutralizing epitopes of PCV2 Cap.

The risk-assessment matrix developed will be used to categorize Alberta pig farms into groups of high and low risk for a PCV2 outbreak. Farms from both groups will be targeted for a second-round of serum sampling in order to further characterize vulnerability and resistance factors for PCV2. This second data set on pig sera will serve both to extend and to validate our risk-assessment matrix.

Our efforts to establish a PCVAD risk-assessment matrix will provide knowledge to guiding the development of tools and practices required for eliminating PCV2 infections from pigs. Although this goal is not included in the current application for funding, it represents one global objective of our efforts. Furthermore, this project supports networking interactions between students, virologists, veterinary practitioners and farmers leading into collaborative research programs and a higher level of preparedness on (re-)/emerging viral diseases of pigs.

Project contact: Dr. Markus Czub, Faculty of Veterinary Medicine, University of Calgary

Collaborating Partners: Dr. Rkia Dardari, Faculty of Veterinary Medicine, University of Calgary
Dr. Frank Marshall, Marshall Swine Health Services, Camrose, Alberta
Dr. Egan Brockhoff, Prairie Swine Health Services, Red Deer, Alberta