PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS: DESCRIPTION OF PERSISTENCE IN INDIVIDUAL PIGS UPON EXPERIMENTAL INFECTION

Authors: ALLENDE, R - UNIVERSITY OF NEBRASKA; Laegreid, William; Kutish, Gerald; GALEOTA, J - UNIVERSITY OF NEBRASKA; WILLS, R - UNIVERSITY OF NEBRASKA; OSORIO, F - UNIVERSITY OF NEBRASKA

Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Persistent infection of pigs by porcine reproductive and respiratory syndrome (PRRS) virus was studied for up to 150 days following infection. The study indicated that persistence of PRRS virus in swine involves continuous replication of the virus. The nucleotide sequence of all PRRS virus structural protein genes and one non-structural gene was determined from viruses isolated at various times following infection. While much of the genomic sequence was stable for the duration of this experiment, some consistent sequence differences were also observed. The results of this study indicate that PRRS virus persists in swine through low-level replication, possibly involving selection of subsets of virus with specific differences in their genomic sequence.

Technical Abstract: We studied the persistence of porcine reproductive and respiratory syndrome virus (PRRSV) in individual experimentally infected pigs, during a period of up to 150 days postinfection (dpi). The results of this study suggest that the persistence of PRRSV involves continuous viral replication but that it is not a true steady-state persistent infection. The virus eventually clears the body and seems to do it in most of the animals by 15 dpi or shortly thereafter. High genetic stability was seen for several regions of the persistent PRRSV's genome, although some consistent mutations in the genes of envelope glycoproteins and M protein were also observed.