Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Proceedings
Publication Acceptance Date: 10/17/1997
Publication Date: N/A
Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) is a diagnostic challenge for veterinarians. The rapid, accurate and efficient diagnosis of PRRS is the first step in designing a herd health program for the control and possible elimination of this disease. One major obstacle to the definitive diagnosis of PRRS is isolation of the PRRS virus (PRRSV). To overcome this diagnostic dilemma only the best samples should be tested for virus; which, in our opinion, are sera collected from weak-born pigs before they suckle and lung lavage samples collected from swine of all ages. We also know that not all fetuses in a litter are transplacentally infected following exposure of the dam to PRRSV. Therefore, only some of the litter may be congenitally infected resulting in a game of chance when it comes to the identification of virus in any one pre-suckle sample. One way to improve the chance of isolating virus is to test more samples; however, economics plays a major role in determining the number of samples that a diagnostic laboratory receives and in general only a few samples are submitted per case. One solution to the costs of virus isolation would be to pool samples and thus test several for the price of one. The objective of this study is to test this possibility. The relative PRRSV titer of sera or lung lavage samples will be evaluated by mixing these samples with known PRRSV-negative sera or lung lavage fluids, respectively. Preliminary results indicate presuckle sera can be pooled at a ratio of 1 positive serum to 9 negative serums without a loss of sensitivity for virus isolation. This data suggests that 10 sera can be tested for the price of 1, resulting in savings to the producer and an increased chance of isolating PRRSV from the additional samples.