Avian biology, the human influence on global avian influenza transmission, and performing surveillance in wild birds

2010 ◽  
Vol 11 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Samantha E. J. Gibbs

AbstractThis paper takes a closer look at three interrelated areas of study: avian host biology, the role of human activities in virus transmission, and the surveillance activities centered on avian influenza in wild birds. There are few ecosystems in which birds are not found. Correspondingly, avian influenza viruses are equally global in distribution, relying on competent avian hosts. The immune systems, annual cycles, feeding behaviors, and migration patterns of these hosts influence the ecology of the disease. Decreased biodiversity has also been linked to heightened disease transmission in several disease systems, and it is evident that active destruction and modification of wetland environments for human use is impacting avian populations drastically. Legal and illegal trade in wild birds present a significant risk for introduction and maintenance of exotic diseases. After the emergence of HPAI H5N1 in Hong Kong in 1996 and the ensuing geographic spread of outbreaks after 2003, both infected countries and those at risk of introduction began intensifying avian influenza surveillance efforts. Several techniques for sampling wild birds for influenza viruses have been applied. Benefits, problems, and biases exist for each method. The wild bird avian influenza surveillance programs taking place across the continents are now scaling back due to the rise of other spending priorities; hopefully the lessons learned from this work will be preserved and will inform future research and disease outbreak response priorities.

2011 ◽  
Vol 32 (1) ◽  
pp. 48

Wild aquatic birds are the natural reservoir for avian influenza viruses (AIVs)1. Increased surveillance has revealed that Australia has its own lineages of these AIVs.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 381
Author(s):  
Eun-Jee Na ◽  
Young-Sik Kim ◽  
Sook-Young Lee ◽  
Yoon-Ji Kim ◽  
Jun-Soo Park ◽  
...  

Wild aquatic birds, a natural reservoir of avian influenza viruses (AIVs), transmit AIVs to poultry farms, causing huge economic losses. Therefore, the prevalence and genetic characteristics of AIVs isolated from wild birds in South Korea from October 2019 to March 2020 were investigated and analyzed. Fresh avian fecal samples (3256) were collected by active monitoring of 11 wild bird habitats. Twenty-eight AIVs were isolated. Seven HA and eight NA subtypes were identified. All AIV hosts were Anseriformes species. The HA cleavage site of 20 representative AIVs was encoded by non-multi-basic amino acid sequences. Phylogenetic analysis of the eight segment genes of the AIVs showed that most genes clustered within the Eurasian lineage. However, the HA gene of H10 viruses and NS gene of four viruses clustered within the American lineage, indicating intercontinental reassortment of AIVs. Representative viruses likely to infect mammals were selected and evaluated for pathogenicity in mice. JB21-58 (H5N3), JB42-93 (H9N2), and JB32-81 (H11N2) were isolated from the lungs, but JB31-69 (H11N9) was not isolated from the lungs until the end of the experiment at 14 dpi. None of infected mice showed clinical sign and histopathological change in the lung. In addition, viral antigens were not detected in lungs of all mice at 14 dpi. These data suggest that LPAIVs derived from wild birds are unlikely to be transmitted to mammals. However, because LPAIVs can reportedly infect mammals, including humans, continuous surveillance and monitoring of AIVs are necessary, despite their low pathogenicity.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 212
Author(s):  
Josanne H. Verhagen ◽  
Ron A. M. Fouchier ◽  
Nicola Lewis

Highly pathogenic avian influenza (HPAI) outbreaks in wild birds and poultry are no longer a rare phenomenon in Europe. In the past 15 years, HPAI outbreaks—in particular those caused by H5 viruses derived from the A/Goose/Guangdong/1/1996 lineage that emerged in southeast Asia in 1996—have been occuring with increasing frequency in Europe. Between 2005 and 2020, at least ten HPAI H5 incursions were identified in Europe resulting in mass mortalities among poultry and wild birds. Until 2009, the HPAI H5 virus outbreaks in Europe were caused by HPAI H5N1 clade 2.2 viruses, while from 2014 onwards HPAI H5 clade 2.3.4.4 viruses dominated outbreaks, with abundant genetic reassortments yielding subtypes H5N1, H5N2, H5N3, H5N4, H5N5, H5N6 and H5N8. The majority of HPAI H5 virus detections in wild and domestic birds within Europe coincide with southwest/westward fall migration and large local waterbird aggregations during wintering. In this review we provide an overview of HPAI H5 virus epidemiology, ecology and evolution at the interface between poultry and wild birds based on 15 years of avian influenza virus surveillance in Europe, and assess future directions for HPAI virus research and surveillance, including the integration of whole genome sequencing, host identification and avian ecology into risk-based surveillance and analyses.


2016 ◽  
Vol 283 (1845) ◽  
pp. 20162159 ◽  
Author(s):  
Sarah C. Hill ◽  
Ruth J. Manvell ◽  
Bodo Schulenburg ◽  
Wendy Shell ◽  
Paul S. Wikramaratna ◽  
...  

For viruses such as avian influenza, immunity within a host population can drive the emergence of new strains by selecting for viruses with novel antigens that avoid immune recognition. The accumulation of acquired immunity with age is hypothesized to affect how influenza viruses emerge and spread in species of different lifespans. Despite its importance for understanding the behaviour of avian influenza viruses, little is known about age-related accumulation of immunity in the virus's primary reservoir, wild birds. To address this, we studied the age structure of immune responses to avian influenza virus in a wild swan population ( Cygnus olor ), before and after the population experienced an outbreak of highly pathogenic H5N1 avian influenza in 2008. We performed haemagglutination inhibition assays on sampled sera for five avian influenza strains and show that breadth of response accumulates with age. The observed age-related distribution of antibody responses to avian influenza strains may explain the age-dependent mortality observed during the highly pathogenic H5N1 outbreak. Age structures and species lifespan are probably important determinants of viral epidemiology and virulence in birds.


2010 ◽  
Vol 5 (s1) ◽  
pp. e178-e179
Author(s):  
Elisa Pérez-ramírez ◽  
Vanessa Rodríguez ◽  
Dagmar Sommer ◽  
Juan Manuel Blanco ◽  
Pelayo Acevedo ◽  
...  

2021 ◽  
Author(s):  
Bethany J. Hoye ◽  
Celeste M. Donato ◽  
Simeon Lisovski ◽  
Yi-Mo Deng ◽  
Simone Warner ◽  
...  

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.


2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Borys Stegniy ◽  
Denys Muzyka ◽  
Mary Pantin-Jackwood ◽  
Oleksandr Rula ◽  
Anton Stegniy ◽  
...  

The abstract is devoted to monitoring studies of circulation of the AIV subtypes H5 and H7 in wild waterfowl and shorebirds around the Azov-Black Sea in Ukraine


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