Avian influenza virus investigation on Italian endangered Phasianidae and Tetraonidae populations

The mechanisms of circulation of avian influenza viruses (AIVs) in domestic Galliformes are well-known, however little information is available about AIV ecology in free-living Galliformes populations. This study is aimed to evaluate whether Phasianidae of genus Alectoris and Tetraonidae of genera Tetrao and Lagopus may play an active role in AIV ecology in the post-reproductive period. These sedentary species are distributed in post-glacial relict populations threatened by global warming; they live in a snowy mountainous region and are characterised by a social behaviour. In 2003 and 2004, during the September-December periods, 79 wild Galliformes, categorised in age and sex classes, were trapped in the Sondrio Province (Lombardy region, Central Alps, Northern Italy); sampling area was place at altitudes between 1400 and 3000 m a.s.l. Cloacal swabs were collected from 11 free-living rock partridges (Alectoris graeca) belonging to Phasianidae family, and from 68 wild Tetraonidae including 23 rock ptarmigans (Lagopus mutus) and 45 black grouses (Tetrao tetrix). Samples were tested by reverse transcription (RT)-PCR for influenza A virus M-gene. No AIV-specific RNA was detected in any of the investigated cloacal swabs samples, thus suggesting the lack of AIV circulation in these relict populations during the study period. In terms of threatened species conservation, the introduction of AIV carrier-birds, possibly related to animal release for restocking purposes, could represent a heath risk for these AIV naïve metapopulations. As a consequence the priority is to check both health and genetic quality in farms that produce birds to be released in fragile ecosystems.