Risks of Avian Influenza Transmission in Areas of Intensive Free-Ranging Duck Production with Wild Waterfowl
For decades, southern China has been considered to be an important source for emerging influenza viruses since key hosts live together in high densities in areas with intensive agriculture. However, the underlying conditions of emergence and spread of avian influenza viruses (AIV) have not been studied in detail, particularly the complex spatiotemporal interplay of viral transmission between wild and domestic ducks, two major actors of AIV epidemiology. In this synthesis, we examine the risks of avian influenza spread in Poyang Lake, an area of intensive free-ranging duck production and large numbers of wild waterfowl. Our synthesis shows that farming of free-grazing domestic ducks is intensive in this area and synchronized with wild duck migration. The presence of juvenile domestic ducks in harvested paddy fields prior to the arrival and departure of migrant ducks in the same fields may amplify the risk of AIV circulation and facilitate the transmission between wild and domestic populations. We provide evidence associating wild ducks migration with the spread of H5N1 in the spring of 2008 from southern China to South Korea, Russia, and Japan, supported by documented wild duck movements and phylogenetic analyses of highly pathogenic avian influenza H5N1 sequences. We suggest that prevention measures based on a modification of agricultural practices may be implemented in these areas to reduce the intensity of AIV transmission between wild and domestic ducks. This would require involving all local stakeholders to discuss feasible and acceptable solutions.
Keywordsavian influenza virus wild birds migration interface contact ecology epidemiology China Poyang telemetry remote sensing GPS
- Chen H, Smith GJD, Li KS, Wang J, Fan XH, Rayner JM, et al. (2006). Establishment of multiple sublineages of H5N1 influenza virus in Asia: Implications for pandemic control. Proceedings of the National Academy of Sciences of the United States of America 103:2845-2850.PubMedCentralPubMedCrossRefGoogle Scholar
- Hulse-Post DJ, Sturm-Ramirez KM, Humberd J, Seiler P, Govorkova EA, Krauss S, et al. (2005). Role of domestic ducks in the propagation and biological evolution of highly pathogenic H5N1 influenza viruses in Asia. Proceedings of the National Academy of Sciences of the United States of America 102:10682-10687.PubMedCentralPubMedCrossRefGoogle Scholar
- Nemeth NM, Brown JD, Stallknecht DE, Howerth EW, Newman SH, and Swayne DE (2013) Experimental infection of Bar-Headed Geese (Anser indicus) and Ruddy Shelducks (Tadorna ferruginea) with a clade 2.3.2 H5N1 highly pathogenic avian influenza virus. Veterinary Pathology 50(6):961-70.PubMedCrossRefGoogle Scholar
- Swofford DL (2003) PAUP*: Phylogenetic Analysis Using Parsimony (*and Other Methods) version 4.0 (Computer program). Sunderland, Massachusetts: Sinauer Associates.Google Scholar