Apparent increase of reported hemorrhagic disease in the midwestern and northeastern USA.

We investigated temporal and spatial trends in reporting of hemorrhagic disease (HD) in the midwestern and northeastern US using a 33-yr (1980-2012) questionnaire-based data set. This data set was supported by an additional 19 yr (1994-2012) of bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) isolation results from clinically affected white-tailed deer (Odocoileus virginianus) in these regions. Both the number of counties that were reported positive for HD and the northern latitudinal range of reported HD increased with time.

The epizootiology of anatid herpesvirus 1 infection in free-flying waterfowl: a comparison of latent and active infections among native waterfowl, captive-reared released ducks, and peridomestic or feral ducks.

The epizootiology of anatid herpesvirus 1 (AHV-1) infection in waterfowl is poorly understood but apparently involves persistence of the virus in latently infected birds. Epornitics have often occurred in captive waterfowl or semiwild ducks in parklike settings, and many wildlife professionals conclude that such ducks may be the source of infection for wild waterfowl. We assessed the prevalence of latent infection and viral shedding from four groups of waterfowl: naturally occurring populations of native waterfowl, captive-reared waterfowl released for shooting, introduced nonmigratory waterfowl (e.

Annual survival of ruddy turnstones is not affected by natural infection with low pathogenicity avian influenza viruses.

The population of ruddy turnstones (Arenaria interpres morinella) that migrates through Delaware Bay has undergone severe declines in recent years, attributable to reduced availability of horseshoe crab (Limulus polyphemus) eggs at this critical spring migration stopover site. Concurrently, this population has experienced annual low pathogenicity avian influenza virus (AIV) epidemics at this same site. Using a prospective cohort study design with birds individually flagged during May-June 2006-2008, we evaluated resighting rates (a proxy for annual survival) between AIV-infected and uninfected birds at 1 yr after capture, testing, and measurement.

Detection of avian influenza viruses from shorebirds: evaluation of surveillance and testing approaches.

Although influenza A viruses have been isolated from numerous shorebird species (Family: Scolopacidae) worldwide, our understanding of natural history of these viruses in this diverse group is incomplete. Gaining this information can be complicated by sampling difficulties related to live capture, the need for large sample sizes related to a potentially low prevalence of infection, and the need to maintain flexibility in diagnostic approaches related to varied capabilities and resources. To provide information relevant to improving sampling and testing of shorebirds for influenza A viruses, we retrospectively evaluated a combined data set from Delaware Bay, USA, collected from 2000 to 2009.