Serological and virological surveys of the influenza A viruses in Antarctic and sub-Antarctic penguins

To evaluate the avian influenza virus (AIV) circulation in Antarctic and sub-Antarctic penguins we carried out a serosurvey on six species from Livingston, Marion and Gough islands. Seropositivity against AIV was performed on serum samples using a competitive enzyme-linked immunosorbent assay and haemagglutination and neuraminidase inhibition assays. Some oropharyngeal and cloacal swabs were also assayed to detect influenza virus genomes by real time reverse transcription-polymerase chain reaction. Overall, 12.1% (n5 140) penguins were seropositive to AIV. By species, we detected 5% (n5 19) and 11% (n5 18) seroprevalence in sub-Antarctic rockhopper penguins (Eudyptes spp.) from Gough and Marion islands, respectively, 42% (n5 33) seroprevalence in macaroni penguins (Eudyptes chysolophus Brandt), but no positives in the three other species, gentoo (Pygoscelis papua Forster; n5 25) and chinstrap penguins (P. antarctica Forster; n5 16), from Livingston Island and king penguins (Aptenodytes patagonicus Miller; n5 27) from Marion Island. While seropositivity reflected previous exposure to the AIV, the influenza genome was not detected. Our results indicate that AIV strains have circulated in penguin species in the sub-Antarctic region, but further studies are necessary to determine the precise role that such penguin species play in AIV epidemiology and if this circulation is species (or genus) specific. Received 19 March 2012, accepted 15 November 2012