Evaluating Effects of AIV Infection Status on Ducks Using a Flow Cytometry-Based Differential Blood Count

Area of Science:

• Veterinary Immunology
• Avian Virology
• Flow Cytometry

Background:

• Ducks are key reservoirs for avian influenza virus (AIV).
• Lack of efficient diagnostic tools hinders immune status assessment in ducks.
• Understanding duck immune responses is crucial for managing AIV and zoonotic risks.

Purpose of the Study:

• Develop an automated differential blood count for mallard ducks (Anas platyrhynchos).
• Establish reference white blood cell (WBC) values for mallards.
• Apply the protocol to assess WBC changes in wild mallards during an AIV field study.

Main Methods:

• A no-lyse no-wash, single-step, one-tube flow cytometry technique was developed.
• Utilized a combination of new monoclonal antibodies and duck/chicken-specific markers.
• Enabled quantification of thrombocytes, granulocytes, monocytes, B cells, CD4+ T cells, and CD8+ T cells.

Main Results:

• The technique is reproducible, accurate, and faster than traditional blood smear analysis.
• Blood samples can be analyzed up to one week after collection.
• Age and sex influence WBC counts in mallards; AIV-infected males showed lymphocytopenia and thrombocytopenia.

Conclusions:

• The developed flow cytometry protocol allows for high-throughput WBC analysis in mallards.
• This tool facilitates large-scale immune monitoring in ducks, an important AIV reservoir host.
• The findings provide insights into duck immune responses to AIV, aiding zoonotic event understanding.