Flying Over an Infected Landscape: Distribution of Highly Pathogenic Avian Influenza H5N1 Risk in South Asia and Satellite Tracking of Wild Waterfowl

Abstract

Highly pathogenic avian influenza (HPAI) H5N1 virus persists in Asia, posing a threat to poultry, wild birds, and humans. Previous work in Southeast Asia demonstrated that HPAI H5N1 risk is related to domestic ducks and people. Other studies discussed the role of migratory birds in the long distance spread of HPAI H5N1. However, the interplay between local persistence and long-distance dispersal has never been studied. We expand previous geospatial risk analysis to include South and Southeast Asia, and integrate the analysis with migration data of satellite-tracked wild waterfowl along the Central Asia flyway. We find that the population of domestic duck is the main factor delineating areas at risk of HPAI H5N1 spread in domestic poultry in South Asia, and that other risk factors, such as human population and chicken density, are associated with HPAI H5N1 risk within those areas. We also find that satellite tracked birds (Ruddy Shelduck and two Bar-headed Geese) reveal a direct spatio-temporal link between the HPAI H5N1 hot-spots identified Correspondence to: Marius Gilbert, e-mail: mgilbert@ulb.ac.be EcoHealth 7, 448-458, 2010 DOI: 10.1007 Original Contribution Ó 2011 The Author(s). This article is published with open access at Springerlink.com (Qinghai Lake), Mongolia, and Russia. This suggests that the continental-scale dynamics of HPAI H5N1 are structured as a number of persistence areas delineated by domestic ducks, connected by rare transmission through migratory waterfowl.

Global mapping of highly pathogenic avian influenza H5N1 and H5Nx clade 2.3.4.4 viruses with spatial cross-validation

“…The absence of duck density may in fact explain a lot of the difference in extrapolating capacity found between the host-model (Set 1) and the land-use and eco-climatic models (Set 2 and 3) that cannot discriminate areas with similar land-use and eco-climatic conditions, but that have very different duck densities. For example, India is predicted at relatively high suitability by the land-use model (Set 2, Figure 4) at a very low suitability by the host-based (except around Bangladesh) reflecting the near-absence of significant domestic duck densities in much of the country, in accordance with previous results (Gilbert et al, 2010). …”

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

“…[10][11][12]15,18 Recent satellite telemetry data suggest that bar-headed geese and ruddy shelduck flight patterns (eg, travel rates and long, uninterrupted flight periods) may lessen the likelihood that these migratory waterfowl species transport H5N1 HPAI viruses over long distances, although the potential for contacting other wild birds and poultry during migration exists, especially for bar-headed geese. The authors suggest that relay transmission involving multiple infected individuals during migration may be a more likely role for bar-headed geese in viral dispersal.…”

“…Such information, in conjunction with bar-headed goose and ruddy shelduck satellite telemetry data, 11,12,27 will provide insight into the potential of these species to contribute to short-or long-term maintenance and dissemination of these new H5N1 HPAI viruses.…”

Rapid Diagnosis of Avian Influenza Virus in Wild Birds: Use of a Portable rRT-PCR and Freeze-dried Reagents in the Field

“…Moreover, deploying costly satellite transmitters on confirmed hosts to track their movements would be invaluable for identifying which species act as long-distance carriers of AIV as well as assessing their migratory performance, habitat preferences and levels of interaction with poultry. Future operational testing in areas of international concern for HPAIV, such as Central and South Asia 13 , would conclusively determine how rapid rRT-PCR units perform under outbreak scenarios when diagnosis of a large number of positive samples is time-critical.…”