Understanding and interpreting PRRSV diagnostics in the context of “disease transition stages”

Herein we review broad issues that affect test performance for agents that produce persistent infections. Using PRRSV as an example, the relationship between “disease transition stages” and “diagnostic transition stages” is discussed using meta-analyses of diagnostic data (n = 4307 results) from the refereed literature to highlight the key issues. Although diagnostic technology will continue to improve, it may be concluded from the analysis that there can be no single best diagnostic approach; rather, the choice of specimen and test must be tailored to the specific testing objective. In most cases, meeting the testing objective(s) will require the use of more than one assay and/or specimen type. •PRRSV infection is characterized by changes in its tissue distribution over time.•Therefore, the rate of PRRSV detection varies over time by specimen-assay selection.•The choice of specimen-assay must be tailored to specific PRRSV testing objectives.