One confirmed and one potential human case of influenza A(H5N1) detected through an expanded subtyping protocol

December 10, 2025
Clinical Microbiology
Grant P Higerd-Rusli, Abraar Karan, Seth A Hoffman, Ingrid E A Morante, ChunHong Huang, Malaya K Sahoo, Matthew M Hernandez, Benjamin A Pinsky
Pathogen:influenza A(H5N1)
Infection Type:Respiratory infection
Pathogen Type:Virus

Summary

This report details two human cases of influenza A(H5N1) detected through expanded subtyping, moving beyond animal exposure-based surveillance. The first case, a confirmed infection, involved a patient presenting with respiratory symptoms. The second, a potential case, also exhibited flu-like illness. Diagnosis relied on advanced molecular methods, specifically universal H5 subtyping of influenza A positive samples, which allowed for the identification of these infections that might otherwise have been missed by standard protocols. This approach highlights the limitations of current surveillance strategies focused solely on known animal contact.

Key note: Expanded subtyping protocols are crucial for detecting community-acquired H5N1 cases and improving public health surveillance.

DOI: 10.1128/asmcr.00165-25