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United States Department of Agriculture

Agricultural Research Service


item Rowland, R R R
item Molina, R
item Hermann, J
item Christopher-hennings
item Nelson, E
item Lunney, Joan
item Leathers, V
item Zimmerman, J

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2005
Publication Date: 12/21/2005
Citation: Rowland, R., Molina, R., Hermann, J., Christopher-Hennings, .J., Nelson, E., Lunney, J.K., Leathers, V., Zimmerman, J. 2005. Management of PRRS Persistence: Studies at the population level persistently infected swine. Meeting Abstract. Proceedings 2005 International PRRS Symposium. #70. Available:

Interpretive Summary:

Technical Abstract: Studies of PRRSV infection in individual animals do not reflect the outcomes observed in swine production systems. The purpose of this study was to perform an extensive analysis of virus replication and immunity in a population of 109 pigs (and 60 control pigs) over a period of up to 203 days. The objectives were to (1) create a sample resource for the PRRS research community, (2) identify virological/immunological correlates of persistence and clearance, (3) develop a model for persistence at the population level. The “Big Pig” project incorporated a multidisciplinary, multi-institutional approach including significant support from industry. The study began with the infection of pigs with VR-2332 and ended with the necropsy of the last pigs on August 25, 2005. During the course of the study, over 20,000 samples, including serum and tissues were distributed to five institutions. Analyses performed in-parallel included QT-PCR of serum and tonsil, cytokine gene expression in lymphoid tissues, serology, neutralizing activity, histopathology, immunohistochemistry, and immune cell phenotyping. Several “satellite” projects were also supported. This study illustrates both the spirit and power of collaboration within the NC-229/CAP framework. Current findings and conclusions are presented in a variety of related abstracts.

Last Modified: 10/19/2017
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