Serology
Haemagglutination Inhibition (HI) tests for Paramyxoviruses and Orthomyxoviruses (PMV and Flu), Infectious Bronchitis Virus (IBV) and Egg Drop Syndrome.
This protocol details the method of haemagglutination inhibition (HI) used to detect antibodies to haemagglutinating viruses including avian influenza virus. Antibodies against the viral surface antibody haemagglutinin (HA) can bind HA and prevent it binding sialic acid on the red blood cells thus preventing red blood cell agglutination. Serum containing antibodies of a certain titre will inhibit agglutination. A panel of viral antigen may therefore be used to screen the isolate for the most probable strains and subtypes. The 'Avian Influenza Screening Test' detailed here is routinely used to test for H5 and H7 antibodies for export and international trade purposes with any positive sample sent for confirmatory testing.
Sources
WOAH Manual of Standards for Diagnostic Tests and Vaccine (PDF, 403kb)
Council Directive 1992: 92/66/EEC