Submitted to: International Symposium on Avian Influenza
Publication Type: Abstract Only
Publication Acceptance Date: 2/12/2002
Publication Date: 4/17/2002
Technical Abstract: Two groups of mature specific-pathogen-free white leghorn hens were inoculated topically with a recent H7N2 avian influenza (AI) virus or subcutaneously with an inactivated oil emulsion vaccine produced from the same AI virus. Antibody levels detected in serum and egg yolk on days 0, 7, 14, 18 and 21 post inoculation (PI) were compared using the agar gel immunodiffusion (AGID) test, the hemagglutination inhibition (HI) test and the enzyme-linked immunosorbent assay (ELISA). Serum from 12 of 12 hens inoculated with the live virus were positive on day 7 PI in the AGID and ELISA tests, 6 of 12 were positive in the HI test. Serum was positive in all three tests by day 14 PI. Yolk from eggs laid by the hens on day 7 PI was negative in all 3 tests and were positive in all tests on day 14 PI. Serum from the 12 vaccinated hens was negative on day 7 PI in the AGID and HI tests, and 5 of 12 were positive in the ELISA test. All 12 serum samples were positive by day 14 PI in the AGID and ELISA tests, and by day 18 PI using the HI test. Six of 12 and 8 of 12 yolk samples were positive on day 14 PI by the AGID and ELISA tests, respectively, and all samples were positive by day 18 PI using these tests. All yolk samples were negative in the HI test up to day 14 PI; five of 12 were positive by day 18 PI and by day 21 PI ten of 12 were positive. These studies show that currently used serological tests can detect antibodies in serum and yolk samples from hens exposed to live AI virus or from those that have been vaccinated. Antibody is detected earlier in the serum than in the yolk, and earlier from a bird exposed to a live infection than from a vaccinated bird.