Rapid tests for on-site detection of HPAI H5 in poultry
A new study evaluated commercially available rapid antigen tests (lateral flow immunoassays, LFIAs) for their suitability as on-site pre-screening tools for detecting highly pathogenic avian influenza virus (HPAIV), particularly H5, in poultry. The aim was not to replace PCR but to provide supportive diagnostic capacity in outbreak situations.
Five tests were initially reviewed; three (Clungene, Biopanda, Anigen) showed the best analytical sensitivity and inclusivity across all hemagglutinin subtypes (H1–H16).
Clungene had the lowest limit of detection (10^6.3 EID50/mL), making it the most sensitive among those tested. All three tests showed high specificity. Clungene performed at 100% for choana swabs and ~94% for chicken cloacal swabs (with one false positive). Biopanda and Anigen showed no false positives in the limited samples tested.
Sensitivity strongly correlated with viral load (PCR Ct values). For Ct ≤ 25 (high viral load), rapid tests performed well (Clungene > 87%). At Ct ≥ 28 (low viral load), sensitivity dropped considerably. Cloacal swabs from ducks had the lowest sensitivity due to generally higher Ct values. The study shows that in practical outbreak settings, rapid tests can reliably detect infection in most flocks, especially when multiple sick or dead birds are sampled.
Rapid antigen tests, particularly Clungene, Biopanda, and Anigen, showed promising sensitivity and specificity for detecting HPAI H5. Their diagnostic performance depends on viral load (Ct value), with best results in respiratory swabs. While PCR remains the gold standard, these tests can be useful tools for rapid flock-level screening in outbreak situations.
