Oral Fluids as an Alternative to Blood Sampling for Surveillance of PCV2 and other Pathogens

November 26, 2008 — 

Effective disease surveillance, control, and prevention can be expensive, but can result in the overall reduction of herd health and veterinary costs in swine farms. One of the tools used for disease surveillance is herd health profiling, that is, determining the health (or immune) status of animals in a herd at a given time, or profiling the health of animals as they move through production. Profiling historically has involved blood sampling of animals, and although useful, systematic disease profiling using blood samples is labor-intensive, cost prohibitive and as result, rarely done. Sampling oral fluids appears to be a simple and cost-effective alternative to blood sampling for the health profiling of large swine herds.

In humans, oral fluids (saliva and other fluids found in the mouth) collected using swabs have been used as samples for the detection of viruses and other signs of infection, including antibodies. In pigs sampled experimentally, oral fluids have been shown to contain detectable levels of Porcine Reproductive and Respiratory virus (PRRSV) RNA, anti-PRRSV antibodies and porcine circovirus type 2 (PCV2) DNA.

With this in mind, Prickett et al. designed a study to find a cost-effective, fast and simple way to obtain oral fluid samples, conserve them and used them for pathogen surveillance on large swine herds. The results showed that oral fluids can be stored in the same manner as serum samples (frozen or chilled for same-day laboratory testing) and be suitable for antibody detection. Higher storage temperatures appear to affect detection of antibodies.

Detailed steps for the collection, handling and submission of oral fluid samples are available from Iowa State University's Veterinary Diagnostic and Production Animal Medicine Web site at http://www.vetmed.iastate.edu/departments/VDPAM/default.aspx?id=7070.

"Practical disease surveillance in growing pig population" and "PRRSV surveillance: Stability of diagnostic targets in oral fluid: sample storage and critical techniques for testing" by J.R. Prickett, et al., pages 139 and 140, Proceeding of the AAVLD 51st Annual Conference, 2008.

Source:
National Pork Board, Porcine Circovirus Outreach

Thanks to NPB's Angela DeMirjyn for forwarding this article.