One-step real-time PCR for avian influenza virus RNA detection in hunted wild birds smuggled into Italy: Risk factors and epidemiological implications

The illegal trade of animals represents a risk factor for transmission of zoonoses to humans, as well as dangerous infections to livestock and wildlife populations (Karesh et al., 2007). In particular, the smuggling of hunted wild birds poses serious risks for the emergence and spread of highly contagious viral diseases such as avian influenza (AI) (OIE, 2010). To assess the health risk of AI virus (AIV) introduction in Italy, we examined hunted wild species, smuggled into Italy. In May 2003, 1132 dead birds were selected among wild species, seized at Bari port, as follows: five Anseriformes species, crucial reservoir of influenza A virus (Webster et al., 1992) (Teal, n. 150; Garganey, n. 110; White-fronted Goose, n. 33; Bean Goose, n. 9, Greylag Goose, n. 4) and one sympatric species (De Marco et al., 2004) of the order Gruiformes (Fulica atra, n. 111); the Woodcock (n. 300), Charadriiformes species playing a little-known role in influenza ecology; the Common Quail (n. 180), Galliformes bird cospecific with the Japanese Quail, an avian species found to be highly AI susceptible (Makarova et al., 2003); two sinanthropic species of Columbiformes (Collared-dove, n. 84, Turtle-dove, n. 151). Cloacal swabs, collected from all birds, were examined by RRT-PCR, specific for the matrix gene of influenza A viruses (Di Trani et al., 2006). Due to the relevant respiratory tropism of AIVs in quails (Makarova et al., 2003 N.V. Makarova, H. Ozaki, H. Kida, R.G. Webster and Perez DR, Replication and transmission of influenza viruses in Japanese quail, Virology 310 (2003), pp. 8–15. Article | PDF (117 K) | View Record in Scopus | Cited By in Scopus (37)Makarova et al., 2003) tracheal swabs were also collected from this species. Only sixteen cloacal swabs, collected from Anseriformes, tested positive for AIVs, with prevalences equal to 8.7% in teals, 0.9% in garganeys and 6.1% in white-fronted geese.Our findings emphasize the need of countering illegal trade of animals. We also confirm the importance of Anseriformes in influenza ecology and the spill-over role of wild Gruiformes, Galliformes and Columbiformes (Delogu et al., 2003). Negative results obtained from woodcocks suggest their marginal role in AIV transmission, likely due to the less use of aquatic habitats compared to other Charadriiformes species (Hanson et al., 2008).