The present invention relates to the field of veterinary diagnostics, specifically to a test for the detection of antibodies against CSFV. In particular the invention relates to a method for detecting antibodies against wild type CSFV in a test sample, characterized in that the method comprises co-incubating with a carrier comprising a mutated TAVSPTTLR epitope of CSFV E2 protein. Further, the invention relates to a diagnostic test kit, and to the use of the method according to the invention. In addition the invention relates to a method for differentiating between animals infected with wild type CSFV and animals that were vaccinated against CSFV with a CSFV (marker) vaccine, and to a method for controlling an infection with wild type CSFV in a population of porcine animals, by the combined use of a CSFV (marker) vaccine and the diagnostic test kit of the invention.
