|Pedersen, Janice - USDA-APHIS-NVSL, AMES,IA|
|Senne, Dennis - USDA-APHIS-NVSL, AMES,IA|
|Panigrahy, B - USDA-APHIS-NVSL, AMES, IA|
Submitted to: Western Poultry Disease Conference
Publication Type: Abstract Only
Publication Acceptance Date: December 13, 2004
Publication Date: April 25, 2005
Citation: Pedersen, J.C., Senne, D.A., Suarez, D.L., King, D.J., Kapczynski, D.R., Panigrahy, B. 2005. Modifications of the official real-time reverse transcriptase polymerase chain reaction (rrt-pcr) assay for the detection of virulent newcastle disease in clinical specimens [abstract]. Western Poultry Disease Conference. p.40. Technical Abstract: Equivalency testing of the real-time reverse transcriptase polymerase chain reaction (RRT-PCR) assay for the detection of virulent Newcastle Disease (vNDV) was evaluated using swab specimens from experimentally infected chickens. Cloacal and oropharyngeal swabs were collected temporally from specific-pathogen free chickens inoculated with Ck/CA/211472-4/03 and tested by virus isolation and RRT-PCR. The previously validated CalMex assay was compared with the modified vNDV RRT-PCR assay using RNA isolated from swab specimens with the standard Qiagen extraction procedure and a magnetic bead extraction procedure for high throughput specimen processing. The new vNDV assay replaces the CalMex assay for the detection of vNDV in the NVSL RRT-PCR protocol used for the surveillance of vNDV by the National Animal Health Laboratory Network. Diagnostic sensitivity and specificity for the modified vNDV RRT-PCR assay, respectively, were 91.26% and 97.5%. This was a significant increase in diagnostic sensitivity compared to the CalMex assay using the same temporal specimens. Volume of swab medum and number of swabs per tube were evaluated as well. The vNDV assay has a diagnostic sensitivity similar to virus isolation and has replaced the CalMex assay in the official NVSL protocol.