Avian Influenza in Wild Birds: Environmental Sampling for the Rapid Detection of Avian Influenza Viruses

All subtypes of influenza Type A viruses infect wild birds, especially waterfowl and shorebirds, but rarely cause disease or mortality in these aquatic species. Aquatic birds are the natural reservoirs for low pathogenic avian influenza viruses (LPAI) that are distributed globally. However, some AI subtypes can be virulent in other animals and humans and some highly pathogenic AI viruses (HPAI) have caused major outbreaks in poultry and even pandemics in the human population. The emergence of a HPAl H5N1 subtype in southeast Asian poultry in 1997 subsequently involved migratory waterfowl in 2005 and has since spread westward throughout the Asian, European, and African continents. This rapid continental spread planned animal and human health agencies in North America and initiated the establishment of a National Strategy for Pandemic influenza in the United States to increase and expand surveillance for the early detection of this virus, to improve and expand preventative measures, and to develop contingency responses to possible outbreaks. One of the methods of emergency surveillance developed and implemented was an interagency, early detection system for HPAI H5N1 avian influenza in wild migratory birds with the potential to bring in the virus from Asia or Europe and spread it throughout North America. As part of this early detection system, the Wildlife Services National Wildlife Research Center developed testing methods, sampling protocols, guidelines, and analyzed 50,184 avian fecal samples collected by Wildlife Service biologists in 50 states and the U. S. territories. Samples were pooled in the laboratory (n = 10,541 pools) and analyzed using RT-PCR. AI viruses were detected in 4.0% of the 10,541 sample pools analyzed and H5/H7 subtypes were detected in 0.2% of the sample pools. Positive H5 and H7 subtypes were shipped to the National Veterinary Services Laboratory for further evaluation and confirmation. This monitoring effort was successful in detecting AI viruses in environmental samples and has proven to be a rapid and cost effective surveillance method

Tracking a Deadly Virus HIGHLY PATHOGENIC AVIAN INFLUENZA IN WILD BIRDS

For Dennis Kohler, the call was somewhat unexpected. On a cold, windy morning in December 2014, Kohler sat in his Colorado office reviewing research plans for upcoming disease studies. A few hours later, Koehler\u27s colleagues at the National Wildlife Health Center in Madison, Wis., called to notify him and other members of the U.S. Department of Agriculture\u27s National Wildlife Disease Program (NWDP) that recent samples collected from wild birds in Washington State had tested positive for highly pathogenic avian influenza (HPAI). Earlier that month, a die-off of mallards (Anas platyrhynchos), American wigeon (A. Americana) and northern pintails (A. acuta) had occurred on Wiser Lake in Whatcom County, Wash., just south of the Canadian border near the site of HP AI outbreaks in British Columbia. State biologists had collected samples for testing, and the analysis revealed the birds likely died of aspergillosis, a common fungal infection. But what was worrisome is that they also tested positive for the Eurasian HS avian influenza virus, marking the first time a highly pathogenic Eurasian strain of avian influenza had been detected in the United States (Ip et al. 201S). Kohler knew an outbreak of HP AI in domestic turkey and chicken flocks in Canada had led the state to conduct enhanced surveillance but was still a little surprised to learn that HP AI had been discovered in wild birds. The NWDP had been monitoring and preparing for HPAI in wild birds since the 200S HPAI HSN1 scare in Southeast Asia that caused officials to kill hundreds of thousands of domestic poultry. Now the virus was confirmed in the U.S. and Kohler needed to mobilize a team of expelts to respond

The Role of the National Wildlife Disease Program in Wildlife Disease Surveillance and Emergency Response

The National Wildlife Disease Program (NWDP), overseen by the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services (WS), was established in 2003 to develop a nationally coordinated wildlife disease surveillance and emergency response system. Since its inception, the NWDP has developed collaborations with over 200 national and international partners. The national partners include state, tribal, federal, and private organizations. These partnerships have resulted in surveillance and management of over 100 pathogens, toxins, and disease syndromes affecting wildlife, domestic animals, and humans. Several of these pathogens, including avian influenza, plague, tularemia, bluetongue, and 10 pathogens carried by feral swine, are monitored on a national or regional scale. The NWDP maintains an archive of select wildlife disease samples. Archived samples are available to scientists at universities and other entities with approved research protocols. The NWDP also serves as Wildlife Services’ primary emergency response unit. The program’s wildlife disease biologists are trained as all-hazard first responders, and the national office coordinates training and mobilization of these and other personnel. Internationally, the NWDP has worked with over 30 countries, developing close relationships with many organizations. This paper provides an overview of the NWDP structure and its activities. Programmatic efforts to address highly pathogenic avian influenza (HPAI) H5N1 are presented as an example of a coordinated national response when a disease risk posed by wildlife presents a potential threat to agriculture or humans

SARS-CoV-2 exposure in wild white-tailed deer (\u3ci\u3eOdocoileus virginianus\u3c/i\u3e)

Widespread human SARS-CoV-2 infections combined with human–wildlife interactions create the potential for reverse zoonosis from humans to wildlife. We targeted white-tailed deer (Odocoileus virginianus) for serosurveillance based on evidence these deer have angiotensin-converting enzyme 2 receptors with high affinity for SARS-CoV-2, are permissive to infection, exhibit sustained viral shedding, can transmit to conspecifics, exhibit social behavior, and can be abundant near urban centers. We evaluated 624 prepandemic and postpandemic serum samples from wild deer from four US states for SARS-CoV-2 exposure. Antibodies were detected in 152 samples (40%) from 2021 using a surrogate virus neutralization test. A subset of samples tested with a SARS-CoV-2 virus neutralization test showed high concordance between tests. These data suggest white-tailed deer in the populations assessed have been exposed to SARS-CoV-2

Characterization of Low-Pathogenicity H5N1 Avian Influenza Viruses from North America▿

Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage