High pathogenicity avian influenza (HPAI) is a viral disease with devastating consequences for the poultry industry worldwide. Domestic ducks are major source of HPAI viruses in many Eurasian countries. The infectivity and vary depending on host factors. To assess factors influencing ducks, we compared pathobiology two (H5N1 clade 2.3.2.1c H5N6 2.3.4.4e) 5- 25-week-old ducks. Both caused mortal...

The Mississippi Flyway midwinter population survey (MWS) indicates that American black ducks (Anas rubripes) have been rapidly declining for the last 10 years. We found a negative relationship between MWS and Ontario (Canada) midwinter counts for black ducks. Thus, as number of black ducks in the MWS decreased, Ontario midwinter counts increased. A shift in midwinter distribution of black ducks...

In Java, Indonesia, during March 2007-March 2008, 96 farms with scavenging ducks that were not vaccinated against highly pathogenic avian influenza (HPAI) were monitored bimonthly. Bird-level (prevalence among individual birds) H5 seroprevalence was 2.6% for ducks and 0.5% for chickens in contact with ducks. At least 1 seropositive bird was detected during 19.5% and 2.0% of duck- and chicken-fl...

We cultured 126 Pasteurella multocida isolates, 92 from water and 34 from sediment samples collected from wetlands in the Pacific and Central flyways of the United States between 1996 and 1999. Most (121) of the isolates were P. multocida serotype 1, but serotypes 3, 3/4, 10, and 11 were also found. Many (82) of the isolates were further characterized by DNA fingerprinting procedures and tested...

Wild birds have been implicated in the expansion of highly pathogenic avian influenza virus (H5N1) outbreaks across Asia, the Middle East, Europe, and Africa (in addition to traditional transmission by infected poultry, contaminated equipment, and people). Such a role would require wild birds to excrete virus in the absence of debilitating disease. By experimentally infecting wild ducks, we fou...

Ducks have many of the same basic external parts as other fowl, such as chickens. However, some unique characteristics exist in the external anatomies of ducks. For example, a duck's head (shown in Figure 1) differs from a chicken's head in several ways. Ducks have no comb and, other than the crested duck, no head covering other than feathers. The bill of a duck is flatter than the beak of a ch...