Title: Serum and egg yolk antibody detection in chickens infected with low pathogenicity avian influenza virus Authors
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2012
Publication Date: September 1, 2012
Citation: Sa E Silva, M., Swayne, D.E. 2012. Serum and egg yolk antibody detection in chickens infected with low pathogenicity avian influenza virus. Avian Diseases. 56:592-596. Interpretive Summary: Serological surveillance for avian influenza viruses are usually performed by detection of antibodies in blood samples. The aim of this study was to evaluate the use of egg samples for antibody detection in the course of a experimental infection of hens. Layers inoculated with an H7N2 mild avian influenza virus were tested for antibody levels in the blood and eggs by using the agar gel immunodiffusion test, hemagglutination-inhibition test and a commercially available enzyme-linked immunosorbent assay. Antibodies for avian influenza virus were detected in egg a few days after the detection in blood, and remained detectible until day 42 after infection. These results suggest that eggs can be an alternative to blood for flock antibody surveillance against avian influenza virus infections.
Technical Abstract: Surveillance for low pathogenicity avian influenza virus (LPAIV) infections has primarily relied on labor intensive collection and serological testing of serum, but for many poultry diseases, easier to collect yolk samples have replaced serum for surveillance testing. A time course LPAIV infection study in layers was performed to evaluate the utility of antibody detection in serum versus egg yolk samples. Layers inoculated with the LPAIV A/Bobwhite Quail/Pennsylvania/20304/98 (H7N2) were tested for antibody levels in the serum and egg yolk by using the agar gel immunodiffusion test (AGID), hemagglutination-inhibition test (HI) and a commercially available enzyme-linked immunosorbent assay (ELISA). Anti-influenza specific antibodies were detected in the serum as early as 7 days post inoculation (DPI), and the majority of the hens remained positive until 42 DPI. Antibodies in the egg yolk were first detected in only one egg by AGID at 7 DPI, but the majority of the eggs became positive by all techniques at day 11 and remained positive until 42 days post inoculation, at which time the number of AGID+ and HI+ samples declined slightly as compared to ELISA+ samples. These results suggest that egg yolk can be an alternative to serum for flock serological surveillance against LPAIV infections, and the three methods (AGID, HI and ELISA) will give similar results for first 42 days after infection.