NR AXDV
AU Reckzeh,C.; Hoffmann,C.; Buschmann,A.; Buda,S.; Budras,K.D.; Reckling,K.F.; Bellmann,S.; Knobloch,H.; Erhardt,G.; Fries,R.; Groschup,M.H.
TI Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock
QU Veterinary Microbiology 2007 Aug 31; 123(4): 320-7
PT journal article
AB To obtain a more detailed understanding of the prevalence of classical scrapie infections in a heavily affected German sheep flock (composed of 603 sheep and 6 goats), we analysed 169 sheep and 6 goats that carried the genotypes susceptible to the disease and that were therefore culled following discovery of the index case. The initial tests were performed using the Biorad TeSeE ELISA and reactive results were verified by official confirmatory methods (OIE-immunoblot and/or immunohistochemistry (IHC)) to demonstrate the deposition of scrapie-associated PrPsc in the brain stem (obex). This approach led to the discovery of 40 additional subclinically scrapie-infected sheep. Furthermore, peripheral lymphatic and nervous tissue samples of the 129 sheep and 6 goats with a negative CNS result were examined by IHC in order to identify any preclinical infections which had not already spread to the central nervous system (CNS). Using this approach we found 13 additional sheep with PrPsc depositions in the gut-associated lymph nodes (GALT) as well as in the enteric nervous system. Moreover, in most of these cases PrPsc was also deposited in the spleen and in the retropharyngeal and superficial cervical lymph nodes. Taken together, these results show a 30.3% infection prevalence in this scrapie-affected flock. Almost 7.4% of the infected animals harboured PrPsc exclusively in the peripheral lymphatic and nervous tissue and were therefore missed by the currently used testing strategy.
IN Erst im Jahr 2007 publizierten Reckzeh et al. die Ergebnisse der Untersuchung von laut Genotypisierung besonders empfänglichen 169 Schafen, die aufgrund eines bereits im Dezember 2003 diagnostizierten Scrapie-Falles in einer danach noch aus 603 Schafen bestehenden Herde in Sachsen Anhalt getötet und per Biorad-ELISA-Schnelltest untersucht wurden. Per ELISA-Schnelltest wurden 40 noch subklinische Scrapie-Fälle entdeckt. Eine immunhistochemische Untersuchung peripherer lymphatischer und neuronaler Gewebe der im Schnelltest negativen Schafe identifizierte in dieser Herde noch weitere 13 Scrapie-Fälle.
MH Animals; Brain Stem/*chemistry/metabolism; Cohort Studies; Diagnosis, Differential; Enzyme-Linked Immunosorbent Assay/methods/veterinary; Female; Genetic Predisposition to Disease/genetics; Genotype; Goat Diseases/diagnosis/*epidemiology/metabolism; Goats; Immunohistochemistry/veterinary; Lymphoid Tissue/chemistry/metabolism; Male; Organ Specificity; Peripheral Nervous System; PrPsc Proteins/*isolation & purification; Prevalence; Scrapie/*diagnosis/*epidemiology/metabolism; Sensitivity and Specificity; Sheep
AD Friedrich-Loeffler-Institut, Institute for Novel and Emerging Diseases, Insel Riems, Germany; Institute of Meat Hygiene and Technology, Faculty of Veterinary Medicine, Freie Universität Berlin, Germany.
SP englisch
PO Niederlande