Pathogens from Wild Birds at the Wildlife–Agriculture Interface

Birds are known to carry pathogens affecting human and agricultural health. Conversely, agricultural operations can serve as sources of pathogens that affect wild bird populations. This chapter provides guidelines to identify focal avian species that frequently use agricultural operations. These guidelines are coupled with identifying host types, such as maintenance and bridge hosts, and potential direct and indirect pathways for pathogen contamination from wild birds to agricultural operations, including patterns of spillover and spillback. The chapter also identifies major bacterial and viral pathogens of concern that are prevalent in birds and that affect human and agricultural health. These pathogens are then used to illustrate disease ecology concepts important at the wildlife–agriculture interface. These microorganisms include food-borne bacteria, influenza A viruses, and Newcastle disease virus. The chapter introduces the concept of contamination potential for categorizing avian species in terms of the risk they pose to contamination of agricultural operations with pathogens of concern. Finally, the chapter examines long-distance movements of wild birds in relation to pathogen introduction and illustrates this with global movement of influenza A viruses by wild birds.

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Tissue tropisms of avian influenza A viruses affect their spillovers from wild birds to pigs

10.1101/2020.04.14.040964 ◽

2020 ◽

Author(s):

Xiaojian Zhang ◽

Fred L. Cunningham ◽

Lei Li ◽

Katie Hanson-Dorr ◽

Liyuan Liu ◽

...

Keyword(s):

Receptor Binding ◽

Influenza A ◽

Wild Birds ◽

Avian Species ◽

Phenotypic Trait ◽

Influenza A Viruses ◽

Ribonucleoprotein Complex ◽

Binding Preference ◽

Upper Respiratory ◽

Tissue Tropisms

AbstractWild aquatic birds maintain a large genetically diverse pool of influenza A viruses (IAVs), which can be transmitted to lower mammals and ultimately humans. Through phenotypic analyses, only a small set of avian IAVs replicated well in the epithelial cells of swine upper respiratory tracts, and these viruses were shown to infect and cause virus shedding in pigs. Such a phenotypic trait appears to emerge randomly and are distributed among IAVs across multiple avian species, geographic and temporal orders, and is determined not by receptor binding preference but other markers across genomic segments, such as those in the ribonucleoprotein complex. This study demonstrates that phenotypic variants exist among avian IAVs, only a few of which may result in viral shedding in pigs upon infection, providing opportunities for these viruses to become pig adapted, thus posing a higher potential risk for creating novel variants or detrimental reassortants within pig populations.Author SummaryHaving both avian-like receptors and human-like α2,6-linked sialic acid receptors, swine serve as a “mixing vessel” for generating human influenza pandemic strains. All HA subtypes of IAVs can infect swine; however, only sporadic cases of avian IAVs are reported in domestic swine. The molecular mechanisms affecting avian IAVs ability to infect swine are still not fully understood. Through phenotypic analyses, this study suggested that tissue tropisms (i.e., in swine upper respiratory tracts) of avian IAVs affect their spillovers from wild birds to pigs, and this phenotype was determined not by receptor binding preference but by other markers across genomic segments, such as those in the ribonucleoprotein complex. In addition, our results showed that such a phenotypic trait was sporadically and randomly distributed among IAVs across multiple avian species, geographic and temporal orders. This study suggested an efficient way for risk assessment of avian IAVs, such as in evaluating their potentials to be transmitted from avian to pigs.

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Characterization of Subtype H6 Avian Influenza A Viruses Isolated From Wild Birds in Poyang Lake, China

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.685399 ◽

2021 ◽

Vol 8 ◽

Author(s):

Zhimin Wan ◽

Qiuqi Kan ◽

Zhehong Zhao ◽

Hongxia Shao ◽

Thomas J. Deliberto ◽

...

Keyword(s):

Genetic Diversity ◽

Avian Influenza ◽

Mammalian Cells ◽

Influenza A ◽

Poyang Lake ◽

Wild Birds ◽

Mouse Lung ◽

Influenza A Viruses ◽

Domestic Poultry ◽

History Of

Subtype H6 avian influenza A viruses (IAVs) are enzootic and genetically diverse in both domestic poultry and wild waterfowl and may cause spillovers in both pigs and humans. Thus, it is important to understand the genetic diversity of H6 IAVs in birds and their zoonotic potential. Compared with that in domestic poultry, the genetic diversity of H6 viruses in wild birds in China has not been well-understood. In this study, five H6 viruses were isolated from wild birds in Poyang Lake, China, and genetic analyses showed that these isolates are clustered into four genotypes associated with reassortments among avian IAVs from domestic poultry and wild birds in China and those from Eurasia and North America and that these viruses exhibited distinct phenotypes in growth kinetics analyses with avian and mammalian cells lines and in mouse challenge experiments. Of interest is that two H6 isolates from the Eurasian teal replicated effectively in the mouse lung without prior adaptation, whereas the other three did not. Our study suggested that there are variations in the mammalian viral replication efficiency phenotypic among genetically diverse H6 IAVs in wild birds and that both intra- and inter-continental movements of IAVs through wild bird migration may facilitate the emergence of novel H6 IAV reassortants with the potential for replicating in mammals, including humans. Continued surveillance to monitor the diversity of H6 IAVs in wild birds is necessary to increase our understanding of the natural history of IAVs.

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Reassortment and persistence of influenza A viruses from diverse geographic origins within Australian wild birds: evidence from a small, isolated population of Ruddy turnstones

Journal of Virology ◽

10.1128/jvi.02193-20 ◽

2021 ◽

Author(s):

Bethany J. Hoye ◽

Celeste M. Donato ◽

Simeon Lisovski ◽

Yi-Mo Deng ◽

Simone Warner ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Wild Birds ◽

Influenza Viruses ◽

Low Density ◽

Isolated Population ◽

Influenza A Viruses ◽

Geographic Origins ◽

Eastern Australia

Australian lineages of avian influenza A viruses (AIVs) are thought to be phylogenetically distinct from those circulating in Eurasia and the Americas, suggesting the circulation of endemic viruses seeded by occasional introductions from other regions. However, processes underlying the introduction, evolution and maintenance of AIVs in Australia remain poorly understood. Waders (Order Charadriiformes, Family Scolopacidae) may play a unique role in the ecology and evolution of AIVs, particularly in Australia, where ducks, geese and swans (Order Anseriformes, Family Anatidae) rarely undertake intercontinental migrations. Across a five-year surveillance period (2011–2015), Ruddy turnstones (Arenaria interpres) that ‘overwinter’ during the Austral summer in south eastern Australia showed generally low levels of AIV prevalence (0–2%). However, in March 2014 we detected AIVs in 32% (95% CI; 25–39%) of individuals in a small, low-density, island population 90km from the Australian mainland. This epizootic comprised three distinct AIV genotypes, each of which represent a unique reassortment of Australian, recently introduced Eurasian, and recently introduced American-lineage gene segments. Strikingly, the Australian-lineage gene segments showed high similarity to H10N7 viruses isolated in 2010 and 2012 from poultry outbreaks 900–1500km to the north. Together with the diverse geographic origins of the American and Eurasian gene segments, these findings suggest extensive circulation and reassortment of AIVs within Australian wild birds over vast geographic distances. Our findings indicate that long-term surveillance in waders may yield unique insights into AIV gene flow, especially in geographic regions like Oceania where Anatidae do not display regular inter- or intracontinental migration. IMPORTANCE High prevalence of avian influenza viruses (AIVs) was detected in a small, low-density, isolated population of Ruddy turnstones in Australia. Analysis of these viruses revealed relatively recent introductions of viral gene segments from both Eurasia and North America, as well as long-term persistence of introduced gene segments in Australian wild birds. These data demonstrate that the flow of viruses into Australia may be more common than initially thought and that, once introduced, these AIVs have the potential to be maintained within the continent. These findings add to a growing body of evidence suggesting Australian wild birds are unlikely to be ecologically-isolated from the highly pathogenic H5Nx viruses circulating among wild birds throughout the northern hemisphere.

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Avian Influenza Virus Prevalence and Subtype Diversity in Wild Birds in Shanghai, China, 2016–2018

Viruses ◽

10.3390/v12091031 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1031

Author(s):

Ling Tang ◽

Wangjun Tang ◽

Xiaofang Li ◽

Chuanxia Hu ◽

Di Wu ◽

...

Keyword(s):

Influenza A ◽

Eastern China ◽

Wild Birds ◽

Influenza A Viruses ◽

Chain Reaction ◽

Virus Prevalence ◽

Total Prevalence ◽

Monitoring Group ◽

Polymerase Chain ◽

Common Teal

From 2016 to 2018, surveillance of influenza A viruses in wild birds was conducted in Shanghai, located at the East Asian–Australian flyway, China. A total of 5112 samples from 51 species of wild birds were collected from three different wetlands. The total three-year prevalence of influenza A viruses among them was 8.8%, as assessed using real-time polymerase chain reaction (PCR) methods, and the total prevalence was higher in Anseriformes (26.3%) than in the Charadriiformes (2.3%) and the other orders (2.4%) in the Chongmin wetlands. Anseriformes should be the key monitoring group in future surveillance efforts. The peak prevalence of influenza A viruses in Charadriiformes were in April and September, and in other bird orders, the peaks were in November and December. Twelve subtypes of haemagglutinin (HA; H1–H12) and eight subtypes of neuraminidase (NA; N1, N2, N4–N9) were identified in 21 different combinations. The greatest subtype diversity could be found in common teal, suggesting that this species of the bird might play an important role in the ecology and epidemiology of influenza A viruses in Shanghai. These results will increase our understanding of the ecology and epidemiology of influenza A viruses in wild bird hosts in eastern China, and provide references for subsequent surveillance of influenza A virus in wild birds in this area.

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Properties and Dissemination of H5N1 Viruses Isolated during an Influenza Outbreak in Migratory Waterfowl in Western China

Journal of Virology ◽

10.1128/jvi.00110-06 ◽

2006 ◽

Vol 80 (12) ◽

pp. 5976-5983 ◽

Cited By ~ 248

Author(s):

Hualan Chen ◽

Yanbing Li ◽

Zejun Li ◽

Jianzhong Shi ◽

Kyoko Shinya ◽

...

Keyword(s):

Influenza A ◽

H5n1 Virus ◽

Rhesus Macaques ◽

Respiratory Illness ◽

Wild Birds ◽

Avian Species ◽

Liaoning Province ◽

Western China ◽

Qinghai Lake ◽

H5n1 Influenza

ABSTRACT H5N1 influenza A viruses are widely distributed among poultry in Asia, but until recently, only a limited number of wild birds were affected. During late April through June 2005, an outbreak of H5N1 virus infection occurred among wild birds at Qinghai Lake in China. Here, we describe the features of this outbreak. First identified in bar-headed geese, the disease soon spread to other avian species populating the lake. Sequence analysis of 15 viruses representing six avian species and collected at different times during the outbreak revealed four different H5N1 genotypes. Most of the isolates possessed lysine at position 627 in the PB2 protein, a residue known to be associated with virulence in mice and adaptation to humans. However, neither of the two index viruses possessed this residue. All of the viruses tested were pathogenic in mice, with the exception of one index virus. We also tested the replication of two viruses isolated during the Qinghai Lake outbreak and one unrelated duck H5N1 virus in rhesus macaques. The Qinghai Lake viruses did not replicate efficiently in these animals, producing no evidence of disease other than transient fever, while the duck virus replicated in multiple organs and caused symptoms of respiratory illness. Importantly, H5N1 viruses isolated in Mongolia, Russia, Inner Mongolia, and the Liaoning Province of China after August 2005 were genetically closely related to one of the genotypes isolated during the Qinghai outbreak, suggesting the dominant nature of this genotype and underscoring the need for worldwide intensive surveillance to minimize its devastating consequences.

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ISOLATION OF ORTHO- AND PARAMYXOVIRUSES FROM WILD BIRDS IN WESTERN AUSTRALIA, AND THE CHARACTERIZATION OF NOVEL INFLUENZA A VIRUSES

Australian Journal of Experimental Biology and Medical Science ◽

10.1038/icb.1984.9 ◽

1984 ◽

Vol 62 (1) ◽

pp. 89-99 ◽

Cited By ~ 49

Author(s):

JS Mackenzie ◽

EC Edwards ◽

RM Holmes ◽

VS Hinshaw

Keyword(s):

Western Australia ◽

Influenza A ◽

Wild Birds ◽

Influenza A Viruses ◽

Novel Influenza A

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Emergence of influenza A viruses

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2001.0997 ◽

2001 ◽

Vol 356 (1416) ◽

pp. 1817-1828 ◽

Cited By ~ 154

Author(s):

R. J. Webby ◽

R. G. Webster

Keyword(s):

Intermediate Host ◽

Influenza A ◽

Influenza Viruses ◽

Human Populations ◽

Aquatic Bird ◽

Intermediate Hosts ◽

Aquatic Birds ◽

Influenza A Viruses ◽

Bird Populations ◽

Human Viruses

Pandemic influenza in humans is a zoonotic disease caused by the transfer of influenza A viruses or virus gene segments from animal reservoirs. Influenza A viruses have been isolated from avian and mammalian hosts, although the primary reservoirs are the aquatic bird populations of the world. In the aquatic birds, influenza is asymptomatic, and the viruses are in evolutionary stasis. The aquatic bird viruses do not replicate well in humans, and these viruses need to reassort or adapt in an intermediate host before they emerge in human populations. Pigs can serve as a host for avian and human viruses and are logical candidates for the role of intermediate host. The transmission of avian H5N1 and H9N2 viruses directly to humans during the late 1990s showed that land-based poultry also can serve between aquatic birds and humans as intermediate hosts of influenza viruses. That these transmission events took place in Hong Kong and China adds further support to the hypothesis that Asia is an epicentre for influenza and stresses the importance of surveillance of pigs and live-bird markets in this area.

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