Infectious laryngotracheitis virus in commercial hens: a serological study based on enzyme-linked immunosorbent assay.
Serum samples collected from 23 flocks of commercial hens from three different companies were tested by enzyme-linked immunosorbent assay (ELISA) for antibodies against infectious laryngotracheitis (ILT) virus, and data were analyzed statistically. Geometric mean titers (GMTs) were compared from hens that were unvaccinated, once-vaccinated, or twice-vaccinated, from single-age farms or multiple-age farms, from molted or unmolted flocks, and from different companies. There were significant differences among the groups compared by vaccination, between the single-age and multiple-age groups, and between the molted and unmolted groups. The GMT of unvaccinated flocks and the GMT of molted flocks that had been vaccinated once as pullets with a chick-tissue-culture-origin (CTCO) live vaccine could not be differentiated. The ELISA is useful to detect and quantitate ILT vaccine-induced antibody, but it does not reliably identify older flocks that were vaccinated at a young age with CTCO vaccine.
Ping Shan Enterprise Co. Ltd., Hong Kong.
V Y
VY
Leong
J R
JR
Glisson
R S
RS
Resurreccion
I H
IH
Cheng
D000375:Aging / Q000276:immunology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002645:Chickens / Q000276:immunology / Q000821:virology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D001352:Herpesvirus 1, Gallid / Q000276:immunology / Q000302:isolation & purification*; D007114:Immunization
D000914:Antibodies, Viral