Avian Influenza Antibody Test Card (Colloidal Gold Method)

Target and Hazard: Avian influenza (AI) is caused by avian influenza virus (AIV), a type A influenza virus of the family Orthomyxoviridae, and mainly affects poultry such as chickens, ducks and geese as well as many wild birds. The highly pathogenic strains among the H5 and H7 subtypes can cause high morbidity and mortality in poultry : highly pathogenic avian influenza is a Class I animal disease in China, while low pathogenic avian influenza is a Class III animal disease. Besides severe economic losses to the poultry industry, some subtypes (e.g. H5N1, H7N9) can infect humans, giving the disease major public-health importance. The virus spreads via the respiratory and digestive routes and through contaminated materials, and transmits rapidly in intensively housed flocks.

Significance of Testing: The card detects AIV antibodies in poultry serum for post-vaccination antibody monitoring and immune-qualification assessment of inactivated AI vaccines, helping farms evaluate herd protection and optimise vaccination schedules, and serving as one means of monitoring AI infection status in flocks. It applies to vaccine-effect assessment, sampling surveys of immune qualification and disease surveillance. Note that a positive antibody result cannot distinguish vaccine-induced from field-virus antibodies; where differentiation is needed, pathogen detection and non-structural protein-related tests should be combined.

Principle: Colloidal gold immunochromatographic competitive (inhibition) assay: the test line (T) is coated with AIV-specific antigen and the conjugate pad contains gold-labelled AIV antibody; antibodies in the sample bind the gold-labelled antibody and block it from being captured at the T line, so a high antibody level gives a weaker or absent T line. An absent (or very faint) T line indicates a positive antibody result, while a clear T line indicates negative. The control line (C) confirms reagent and procedure validity.

Performance and Applications: No instrument required; visual reading within 10–15 minutes; samples: serum or plasma (collected per the accompanying instructions); stored and shipped at room temperature — suitable for on-site rapid testing at poultry farms, poultry cooperatives, primary veterinary stations and animal disease prevention and control institutions. Method: colloidal gold immunochromatographic assay (competitive/inhibition format) | Samples: serum, plasma | Time to result: 10–15 min | Reading: visual assessment of T/C lines — in this competitive (inhibition) format an absent or very faint T line indicates a positive antibody result, a clear T line indicates negative; C line is the procedural control | Format: tests/box (as stated on the label) | Storage: 2–30 °C, cool and dry; shelf life 18 months | Note: sensitivity, specificity, limit of detection, intra-/inter-assay CV and agreement with haemagglutination inhibition/virus neutralisation tests are subject to our internal QC report.