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.

Influenza-A viruses in ducks in northwestern Minnesota: fine scale spatial and temporal variation in prevalence and subtype diversity.

Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July-October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.

Avian influenza viruses and avian paramyxoviruses in wintering and breeding waterfowl populations in North Carolina, USA.

Although wild ducks are recognized reservoirs for avian influenza viruses (AIVs) and avian paramyxoviruses (APMVs), information related to the prevalence of these viruses in breeding and migratory duck populations on North American wintering grounds is limited. Wintering (n=2,889) and resident breeding (n=524) ducks were sampled in North Carolina during winter 2004-2006 and summer 2005-2006, respectively. Overall prevalence of AIV was 0.

Influenza A viruses in American White Pelican (Pelecanus erythrorhynchos).

The role of many wild waterbird species in the ecology and epidemiology of avian influenza viruses (AIV) remains unclear. We report the first isolation of AIV from American White Pelicans (Pelecanus erythrorhynchos; Pelecaniformes) in North America. Two H13N9 AIVs were isolated from hatchling birds in breeding colonies in Minnesota, USA, during 2007 and 2008.

Canada geese and the epidemiology of avian influenza viruses.

Canada geese (Branta canadensis) are numerous, highly visible, and widely distributed in both migratory and resident populations in North America; as a member of the order Anseriformes, they are often suggested as a potential reservoir and source for avian influenza (AI) viruses. To further examine the role of Canada Geese in the ecology of AI, we re-evaluated existing literature related to AI virus in this species and tested breeding populations of Canada Geese from three states (Georgia, West Virginia, and Minnesota, USA) by virus isolation and serology. The ability of AI virus to persist in goose feces under experimental conditions also was evaluated as an additional measure of the potential for this species to serve as an AI virus reservoir.

Avian paramyxoviruses in shorebirds and gulls.

There are nine serotypes of avian paramyxovirus (APMV), including APMV-1, or Newcastle disease virus. Although free-flying ducks and geese have been extensively monitored for APMV, limited information is available for species in the order Charadriiformes. From 2000 to 2005 we tested cloacal swabs from 9,128 shorebirds and gulls (33 species, five families) captured in 10 states within the USA and in three countries in the Caribbean and South America.

Avian influenza virus in aquatic habitats: what do we need to learn?

Although aquatic habitats utilized by wild and domestic birds potentially can provide a bridge for avian influenza virus (AIV) transmission among many diverse hosts, the factors controlling environmental persistence and transmission via these habitats are poorly understood. AIV has been detected in water samples collected in the field, and under experimental laboratory conditions, these viruses can remain infective in water for periods of time that would be consistent with an environmental reservoir. However, the application of laboratory results to field realities is complicated by the complexity and scale of these systems.

Phylogenetic comparison of the S10 genes of recent isolates of bluetongue virus from the United States and French Martinique Island.

The sequences of the S10 genes of 28 recent isolates (1994-2004) of bluetongue virus (BTV) from the United States (US) and French Martinique Island (2006) in the Caribbean Basin were compared in phylogenetic analyses to those of viruses previously isolated in the same regions. Although the analyses segregated the recent virus isolates from the two regions into distinct topotype clusters, the analyses also confirm that viruses from the US and the Caribbean Basin/Central America can share similar S10 genes despite the fact that distinct constellations of BTV serotypes occur in the two regions.

First report of bluetongue virus serotype 1 isolated from a white-tailed deer in the United States.

In November 2004, tissues were collected from a hunter-killed white-tailed deer in St. Mary Parish, Louisiana. Bluetongue virus (BTV) was isolated from the tissues; however, the isolate could not be identified as any of the US domestic serotypes.