Avian Infectious Bronchitis Virus Infections in chickens: Virus Exccretion and Immune Response

Avian infectious bronchitis virus (AIBV), a coronavirus, causes acute respiratory disease in chickens. A rapid diagnostic method was developed for the detection of AIBV in infected chickens using a modified indirect double antibody sandwich (MIDAS) enzyme-linked immunosorbent assay (ELISA). The system was compared with isolation of virus by the conventional use of chicken embryos. The MIDAS ELISA was as sensitive as isolation of virus with the use of chicken embryos. However, the MIDAS ELISA was more rapid and easier to apply than the use of chicken embryos. In detecting antibody against indirect (MI) ELISA was also developed. AIBV, a modified The MI ELISA was used to study the immune response of experimentally infected chickens. Results indicated that antibody was not detected in chickens prior to infection, however, the antibody increased in titer as the infection progressed. With increased antibody levels in chickens, shedding of the virus in the trachea and the intestines gradually decreased and disappeared, except in two of eleven chickens whereby virus shedding persisted in the intestines for as long as twenty-eight days and in the presence of humeral antibodies