Comparison of Rapid Antigen Test and Quantitative PCR for Detection of Highly Pathogenic Avian Influenza Virus in Free-Ranging Peruvian Seabirds.

The recent highly pathogenic avian influenza (HPAI) outbreak in Peru devastated seabird populations and was associated with mass mortality events in marine mammals. The first mortality events were observed in coastal Peru in 2022, with the death of hundreds of Peruvian Pelicans (Pelecanus thagus). The outbreak response included health assessments and attempts to use rapid virus detection methods in the field on live and dead birds. Our study compared the FluDETECT Avian rapid antigen screening test that is commonly used in poultry with reverse transcription quantitative PCR (RT-qPCR) for the detection of HPAI virus in Peruvian seabirds. In total, 43 birds across five species were evaluated in this study: Humboldt Penguins (Spheniscus humboldti; n=6), Guanay Cormorants (Leucocarbo bougainvilliorum [Phalacrocorax bougainvillii]; n=19), Peruvian Pelicans (n=13), Kelp Gulls (Larus dominicanus; n=2), and Peruvian Boobies (Sula variegata; n=3). We did not find agreement between the results of the rapid antigen test and the RT-qPCR (Cohen kappa=0.14). The diagnostic sensitivity of the rapid test was low (33%), whereas the specificity was 100%. Based on these findings, we do not recommend the FluDETECT Avian rapid antigen test for influenza screening in seabird species, although given the high specificity, a positive result from this rapid test should be interpreted as a true positive.