PRRSv Surveillance Calculator Developed

April 7, 2009 — 

Dr. Albert Rovira has developed a web-based interactive model for PRRSv monitoring in boar studs.

This mathematical model recreates what happens in a boar stud when it gets infected with PRRSv, based on data from actual PRRSv outbreaks. The model simulates PRRSv spread within the boar stud over time. In addition, the number of animals that would test positive to PCR (semen, serum or blood swab) and ELISA (serum) are simulated, taking into account the different sensitivities of the tests at different stages of infection. Based on this transmission model, the ability of many different surveillance protocols to detect a PRRSv introduction in a boar stud were estimated. The protocols evaluated included the use of different diagnostic tests, sample specimen, sampling frequency, sample sizes and pooling strategies.

The results of the model have been compiled in a database which can be accessed online by AASV members on the AASV website in the form of an online calculator. The calculator will estimate the ability of a certain protocol to detect a PRRSv introduction in a naïve boar stud within defined time periods. The user will input the size of the boar stud (inventory) and the characteristics of the surveillance protocol (sample, sample size, sampling frequency and pooling strategy). The calculator will return the probability of detecting a PRRSv introduction within the first 7 or 14 days or before prevalence reaches 10 or 20%.

Details for using the online calculator were presented by Dr. Rovira during the Boar Stud pre-conference workshop at the 2009 AASV Annual Meeting in Dallas, TX. His publication entitled Web-based Interactive Model for PRRSV Monitoring is available online to AASV members who have purchased the 2009 Swine Information CD. You may also contact Dr. Rovira at rove0010@umn.edu or by phone (612-625-7702) at the University of Minnesota Diagnostic Laboratory.

The AASV wishes to thank Dr. Rovira for making this useful tool available to AASV members and also the AASV Boar Stud Committee for its input and review during the development of the calculator.