Assessment of international inter-laboratory comparison tests for the diagnosis of classical swine fever from 1998 until 2007.

The inter-laboratory comparison tests for classical swine fever (CSF) laboratory diagnosis organised by the European Community Reference Laboratory for CSF are regularly performed within European Union Member States. The objective of this study was to evaluate the results of the inter-laboratory comparison tests carried out over the last decade, from 1998 until 2007, by using a statistical approach. A set of five or six lyophilised sera was sent to participants. These included sera containing CSF antibodies, sera containing antibodies against ruminant pestiviruses, sera containing CSF virus and negative sera. This study focused on the results of the diagnostic reference methods for CSF: the neutralisation test for the detection of CSF antibodies (including its interpretation) and virus isolation for the detection of CSF virus. For the detection of CSF antibodies, results were closest to what was expected by the Community Reference Laboratory when only neutralisation tests were performed. The percentage of correct results decreased as soon as the results of CSF antibody enzyme-linked immunosorbent assay were included or when sera with antibodies to ruminant pestiviruses were added to the panel. The results for the detection of CSF antibodies are still valid today, as no additional method has been introduced recently. Regarding CSF virus detection, CSF virus isolation is well established but on the way to being superseded as the reference test by reverse-transcription polymerase chain reaction.