Antigen-capture ELISA for rapid diagnosis of avian influenza virus in commercial turkey flocks

Comparative examination of a rapid immunocytochemical test for the detection of highly pathogenic avian influenza virus in domestic birds in field outbreaks

The quantitative real-time reverse polymerase chain reaction (RRT-PCR) is the preferred test method for the diagnosis of avian influenza (AI), but can be performed only in specialized laboratories. Different antigen detection methods for the diagnosis of AI were previously reported to be specific and sensitive in field outbreaks. These tests can be performed in basic countryside labs. Brain smears of domestic birds (n = 105) collected during AI field outbreaks were examined with immunocytochemistry (IC). The results were statistically analysed by comparing IC to brain histology (BH), and immunohistochemistry (IHC), to gross pathological examination (GP) (n = 105), and RRT-PCR (n = 91). AI was diagnosed with RRT-PCR in 66 cases. IC and IHC were positive in 59/66 (90%) and 60/66 (91%) cases, respectively. Lesions suspicious for AI were detected with GP and HP in 66/66 (100%) and 61/66 (92%) cases, respectively. An almost perfect agreement was found between RRT-PCR, IC, IHC, and HP. Substantial agreement was found between IC and GP, between IHC and GP, between HP and GP, and between RRT-PCR and GP. The chromogen-based IC test presented in this study produces durable staining, which can be evaluated using a simple brightfield microscope. The test is rapid (can be completed in 2 h), sensitive (90%), specific (100%), and cost-effective, which makes the method suitable for routine diagnostic tests in AI epidemics.RESEARCH HIGHLIGHTSAvian influenza virus (AIV) antigen detection was examined in field outbreaks.Bird brain smears were tested using immunocytochemistry (IC).IC results strongly correlated with real-time RT-PCR results.The IC method was rapid, specific, sensitive, and cost-effective in AIV field outbreaks.

Detection of Influenza A Antibodies in Avian Samples by ELISA

ELISA assays are a fast and relatively inexpensive way to screen sera for antibodies to avian influenza virus. Commercial ELISA kits are available, and although they are more expensive than in-house tests, they provide a ready-to-use assay with good quality control. Numerous sample types can be processed for ELISA: serum, plasma, egg yolk, or blood collected on filter paper. High-quality samples are critical to accurate results. The basics of AIV antibody ELISA, sample processing, result interpretation, and troubleshooting are discussed.

Detection of influenza A antibodies in avian serum samples by ELISA

ELISA assays are a fast and relatively inexpensive way to screen sera for antibodies to avian influenza virus. Commercial ELISA kits are available, and although they are more expensive, they provide a ready-to-use assay with good quality control. Various sample types can be processed for ELISA: serum, plasma, egg yolk, blood collected on filter paper. Quality samples are critical to accurate results. The basics of AIV antibody ELISA, sample processing, results interpretation, and troubleshooting are discussed.