Evaluation of PCR-based hemagglutinin subtyping as a tool to aid in surveillance of avian influenza viruses in migratory wild birds.

The surveillance of migratory wild birds (MWBs) for avian influenza virus (AIV) allows detecting the emergence of highly pathogenic AIV that can infect domestic poultry and mammals, new subtypes, and antigenic/genetic variants. The current AIV surveillance system for MWBs in the United States is based on virus isolation (VI) followed by sequencing isolates. This system primarily focuses on the early detection of H5 and H7 AIVs.

Tissue tropisms opt for transmissible reassortants during avian and swine influenza A virus co-infection in swine.

Genetic reassortment between influenza A viruses (IAVs) facilitate emergence of pandemic strains, and swine are proposed as a "mixing vessel" for generating reassortants of avian and mammalian IAVs that could be of risk to mammals, including humans. However, how a transmissible reassortant emerges in swine are not well understood. Genomic analyses of 571 isolates recovered from nasal wash samples and respiratory tract tissues of a group of co-housed pigs (influenza-seronegative, avian H1N1 IAV-infected, and swine H3N2 IAV-infected pigs) identified 30 distinct genotypes of reassortants.

LEPTOSPIRA ANTIBODIES DETECTED IN WILDLIFE IN THE USA AND THE US VIRGIN ISLANDS.

From 2011 to 2017, 4,534 serum samples from 13 wildlife species collected across the US and in one territory (US Virgin Islands) were tested for exposure to Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. Of 1,759 canids, 1,043 cervids, 23 small Indian mongooses ( Herpestes auropunctatus), 1,704 raccoons ( Procyon lotor), and five striped skunks ( Mephitis mephitis), 27.0, 44.

Feral Swine in the United States Have Been Exposed to both Avian and Swine Influenza A Viruses.

Influenza A viruses (IAVs) in swine can cause sporadic infections and pandemic outbreaks among humans, but how avian IAV emerges in swine is still unclear. Unlike domestic swine, feral swine are free ranging and have many opportunities for IAV exposure through contacts with various habitats and animals, including migratory waterfowl, a natural reservoir for IAVs. During the period from 2010 to 2013, 8,239 serum samples were collected from feral swine across 35 U.

Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America.

Limited Antigenic Diversity in Contemporary H7 Avian-Origin Influenza A Viruses from North America.

Subtype H7 avian-origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Here we antigenically and genetically characterized 93 AIV isolates from North America (85 from migratory waterfowl [1976-2010], 7 from domestic poultry [1971-2012], and 1 from a seal [1980]). The hemagglutinin gene of these H7 viruses are separated from those from Eurasia.

Dynamics of virus shedding and antibody responses in influenza A virus-infected feral swine.

Given their free-ranging habits, feral swine could serve as reservoirs or spatially dynamic 'mixing vessels' for influenza A virus (IAV). To better understand virus shedding patterns and antibody response dynamics in the context of IAV surveillance amongst feral swine, we used IAV of feral swine origin to perform infection experiments. The virus was highly infectious and transmissible in feral swine, and virus shedding patterns and antibody response dynamics were similar to those in domestic swine.

Exposure of feral swine (Sus scrofa) in the United States to selected pathogens.

Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine, respectively, in the US to evaluate exposure to important swine endemic pathogens. Antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) were found in 2.

Large-scale avian influenza surveillance in wild birds throughout the United States.

Avian influenza is a viral disease that primarily infects wild and domestic birds, but it also can be transmitted to a variety of mammals. In 2006, the United States of America Departments of Agriculture and Interior designed a large-scale, interagency surveillance effort that sought to determine if highly pathogenic avian influenza viruses were present in wild bird populations within the United States of America. This program, combined with the Canadian and Mexican surveillance programs, represented the largest, coordinated wildlife disease surveillance program ever implemented.

Influenza A subtype H3 viruses in feral swine, United States, 2011-2012.

To determine whether, and to what extent, influenza A subtype H3 viruses were present in feral swine in the United States, we conducted serologic and virologic surveillance during October 2011-September 2012. These animals were periodically exposed to and infected with A(H3N2) viruses, suggesting they may threaten human and animal health.

Pseudorabies in feral swine in the United States, 2009-2012.

Although pseudorabies virus can affect a wide range of mammalian and avian hosts, swine are the only natural hosts of the virus. The US commercial swine industry obtained pseudorabies-free status in 2004, which was important because of the economic value of domestic swine production; however, feral swine remain competent hosts and represent a constant threat for reintroducing the virus into the commercial industry. To better assess feral swine infection status, we collected 8,498 serum samples from feral swine across the United States between 1 October 2009 and 30 September 2012.

Surveillance for avian influenza viruses in wild birds in Denmark and Greenland, 2007-10.

In Denmark and Greenland, extensive surveillance of avian influenza (AI) viruses in wild bird populations has been conducted from 2007 through 2010. In Denmark, the surveillance consisted of passive surveillance of wild birds found dead or sick across Denmark and active surveillance of apparently healthy live birds in waterfowl reservoirs and along migratory flyways, birds living in proximity to domestic poultry, and hunted game birds. Dead birds were sampled by oropharyngeal swabbing.

Widespread avian bornavirus infection in mute swans in the Northeast United States.

Avian bornavirus (ABV) matrix (M) genes were detected by RT-PCR on brain tissue obtained from 192 mute swans harvested from several Northeastern states. A RT-PCR product was detected in 45 samples. Sequencing of the PCR products confirmed the presence of ABV belonging to the 'goose' genotype.

Yersinia pestis: examining wildlife plague surveillance in China and the USA.

Plague is a zoonotic disease caused by the bacterium Yersinia pestis Lehmann and Neumann, 1896. Although it is essentially a disease of rodents, plague can also be transmitted to people. Historically, plague has caused massive morbidity and mortality events in human populations, and has recently been classified as a reemerging disease in many parts of the world.

Surveillance for highly pathogenic avian influenza in wild birds in the USA.

As part of the USA's National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261,946 samples from wild birds and 101,457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213,115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively.