HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Brown, J. D. Articles by Swayne, D. E. Search for Related Content PubMed PubMed Citation Articles by Brown, J. D. Articles by Swayne, D. E.

¹ Southeastern Cooperative Wildlife Disease Study, Department of Population Health, Wildlife Health Building, College of Veterinary Medicine, The University of Georgia, Athens, Georgia 30602, USA
² Department of Health Administration, Biostatistics, and Epidemiology, College of Public Health, University of Georgia, Athens, Georgia 30602, USA
³ US Department of Agriculture, Agricultural Research Service, Southeast Poultry Research Laboratory, Athens, Georgia 30605, USA
⁴ Corresponding author (email: jbrown{at}vet.uga.edu).

ABSTRACT:   Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in numerous species of wild birds; this is atypical for avian influenza virus (AIV) infections in these avian species, especially for species within the order Anseriformes. Although these infections document the susceptibility of wild birds to H5N1 HPAI viruses and the spillover of these viruses from infected domestic birds to wild birds, it is unknown whether H5N1 HPAI viruses can persist in free-living avian populations. In a previous study, we established that wood ducks (Aix sponsa) are highly susceptible to infection with H5N1 HPAI viruses. To quantify this susceptibility and further evaluate the likelihood of H5N1 HPAI viral maintenance in a wild bird population, we determined the concentration of virus required to produce infection in wood ducks. To accomplish this, 25 wood ducks were inoculated intranasally at 12–16 wk of age with decreasing concentrations of a H5N1 HPAI virus (A/Whooper Swan/Mongolia/244/05 [H5N1]). The median infectious dose and the lethal dose of H5N1 HPAI virus in wood ducks were very low (10^0.95 and 10^1.71 median embryo infectious dose [EID₅₀]/ml, respectively) and less than that of chickens (10^2.80 and 10^2.80 EID₅₀/ml). These results confirm that wood ducks are highly susceptible to infection with H5N1 HPAI virus. The data from this study, combined with what is known experimentally about H5N1 HPAI virus infection in wood ducks and viral persistence in aquatic environments, suggest that the wood duck would represent a sensitive indicator species for H5N1 HPAI. Results also suggest that the potential for decreased transmission efficiency associated with reduced viral shedding (especially from the cloaca) and a loss of environmental fitness (in water), may be offset by the ability of this virus to be transmitted through a very low infectious dose.
  Key words:  Aix sponsa, avian influenza virus, BID₅₀, BLD₅₀, H5N1, highly pathogenic avian influenza, infectious dose, susceptibility, wood duck.