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United States Department of Agriculture

Agricultural Research Service

Title: Development and evaluation of an avian influenza (AI) neuraminidase subtype 1 (N1) based serological ELISA for poultry using the differentiation of infected and vaccinated animals (DIVA)approach)

Author
item Liu, Yuru
item Sylte, Matt
item Swayne, David
item Mundt, Egbert
item Garcia, Maricarmen

Submitted to: International Symposium on Avian Influenza
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2009
Publication Date: 4/5/2009
Citation: Liu, Y., Sylte, M., Swayne, D.E., Mundt, E., Garcia, M. 2009. Development and evaluation of an avian influenza (AI) neuraminidase subtype 1 (N1) based serological ELISA for poultry using the differentiation of infected and vaccinated animals (DIVA)approach [abstract]. Abstracts of the 7th International Symposium on Avian Influenza, April 5-8, 2009, Athens, Georgia. p. 67.

Interpretive Summary:

Technical Abstract: An indirect enzyme-linked immunosorbent assay (ELISA) was developed using baculovirus expressed N1 protein from the A/CK/Indonesia/PA/2003 (H5N1) virus. The specificity of the assay was tested with a panel of chicken anti-sera raised against N1 to N9 virus subtypes. The N1-ELISA was specific for the detection of N1 antibodies in chicken serum raised against North America H1N1 viruses with a percentage of agreement of 70 to 73% when compared to commercially available ELISAs. The ability of the N1-ELISA to detect vaccinated/infected birds in specific pathogen free (SPF) chickens vaccinated with H5N2, H5N9, and infected with Asian H5N1 viruses; and chickens vaccinated with Pox-H7 vector vaccine and infected with highly pathogenic H7N1 virus. Serum samples were collected pre-challenge (n=45), 14 days post-challenge (n=45), and tested by hemagglutining inhibition (HI), quantitative neuraminidase inhibition (NI), and the N1-ELISA. At two days post-challenge oropharyngeal swabs were collected for virus isolation (VI) to confirm infection. As compared to VI, the analytical specificity (Sp) of the N1-ELISA was estimated at a ratio of 1.00, and the analytical sensitivity (Se) was estimated at a ratio of 0.51. N1 antibodies were detected by N1-ELISA and NI assay on 40% and 73% of the samples tested, respectively. Although the N1-ELISA showed lower sensitivity, it was shown that screening for N1 antibodies by ELISA was an effective and rapid assay to identify exposure to the challenge virus during a differentiation of infected from vaccinated animals (DIVA) vaccination strategy. However, the N1-ELISA should be utilized and interpreted as a flock assay, and should be complemented with other rapid diagnostic assay.

Last Modified: 8/24/2016
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