Evaluation of the effectiveness of the hemagglutination inhibition (hi) test in the diagnosis of avian influenza

Аннотация

Avian influenza remains one of the most CITATION dangerous viral infections affecting both wild and I.B. Butaeva. (2025). Evaluation of the effectiveness of the hemagglutination inhibition (hi) test in the diagnosis of avian influenza. domestic birds. Effective diagnostics are essential to The American Journal of Veterinary Sciences and Wildlife Discovery, prevent outbreaks and virus dissemination. This article 7(03), 6–13. https://doi.org/10.37547/tajvswd/Volume07Issue03-02 \ discusses the use of the hemagglutination inhibition test (HI test) as a standard serological method for identifying antibodies against the avian influenza virus. The methodology for performing the HI test, interpretation COPYRIGHT © 2025 Original content from this work may be used under the terms of results, and its significance in the veterinary control of the creative commons attributes 4.0 License. system in the Republic of Uzbekistan are presente. Keywords: Avian influenza, HI test, diagnostics, serology, H5N1 virus, infection control. Introduction: Avian influenza is a highly pathogenic viral disease caused by various subtypes of influenza A virus, particularly H5 and H7. The disease poses a serious threat both to poultry farming and human health. Among various diagnostic methods, the hemagglutination inhibition (HI) test holds a prominent place due to its utility in virus serotyping and determining antibody levels in serum from infected or vaccinated birds. METHODS Study subjects: Serum samples were collected from chickens raised at the poultry farm LLC "Afrosiab Parranda" (Samarkand region) following vaccination against avian influenza (strain H5). Antigens and erythrocytes: Inactivated H5N1 subtype avian influenza virus was used as the antigen. Chicken erythrocytes were used at a concentration of 1% in The American Journal of Veterinary Sciences and Wildlife Discovery 06 https://www.theamericanjournals.com/index.php/tajvswd The American Journal of Veterinary Sciences and Wildlife Discovery Alsever’s solution. monitoring for export purposes. HI test procedure: CONCLUSION • Serum samples were heat-inactivated at 56°C The hemagglutination inhibition test is a reliable for 30 minutes. diagnostic tool for avian influenza. At the poultry farm LLC "Afrosiab Parranda," the method showed high • Serial twofold dilutions of sera were prepared informativeness and reproducibility. The obtained in 96-well plates. results can be utilized to adjust vaccination protocols • Virus antigen was added, followed by and enhance biosecurity measures. incubation for 30 minutes at room temperature. Conducting the HI test allowed for the assessment of • Chicken erythrocytes were then added, and post-vaccination immunity against avian influenza virus. the plates were incubated for an additional 30-45 An overall immunity rate of 85% confirmed the minutes. effectiveness of the vaccination program. Nevertheless, • Results were assessed based on the presence younger birds showed a slightly reduced seropositivity or absence of hemagglutination. rate (76%), indicating a necessity for ongoing RESULTS monitoring and, if needed, adjustment of the vaccination scheme. Blood samples for HI testing were collected between 21–28 days post-vaccination, aligning with the optimal REFERENCES period for the development of post-vaccination Capua I., Alexander D.J. Avian influenza and human immunity. The overall immunity rate was found to be health. Acta Tropica, 2002. 85%, which is a satisfactory level of protection WHO Manual on Animal Influenza Diagnosis and according to veterinary norms. Surveillance, 2002. According to the vaccine manufacturer's instructions, Дадабаев Ш.Х. и др. Методические рекомендации immunity duration post-vaccination is up to 6 months, по диагностике гриппа птиц. Ташкент, 2021. provided that vaccine administration protocols are Office International des Epizooties (WOAH). Manual of strictly followed and no immunosuppressive factors Diagnostic Tests and Vaccines for Terrestrial Animals, are present. 2021. The analysis included two age categories: young birds (up to 6 months old) and adults. A total of 120 serum samples were examined, of which 70 were from adult chickens and 50 from young birds. Positive antibody detection in adults was observed in 64 cases (91.4%), whereas among young birds, antibodies were detected in 38 cases (76%). Thus, it can be concluded that adult chickens developed reliable immunity, while younger birds demonstrated a lower immunity level, indicating the need for additional monitoring and potential revaccination. Among the 120 samples studied, the average antibody titer was 1:64, confirming the vaccine’s effectiveness.