scholarly journals Competition between IAV subtypes through heterosubtypic immunity modulates re-infection and antibody dynamics in the mallard reservoir

2016 ◽  
Author(s):  
Neus Latorre-Margalef ◽  
Justin D. Brown ◽  
Alinde Fojtik ◽  
Rebecca L. Poulson ◽  
Deborah Carter ◽  
...  
Keyword(s):  
Influenza A ◽  
Wild Bird ◽  
Host Population ◽  
Human Populations ◽  
Influenza A Viruses ◽  
Initial Infection ◽  
Bird Populations ◽  
Heterosubtypic Immunity ◽  
Avian Populations ◽  
H3n8 Virus

AbstractOur overall hypothesis is that host population immunity directed at multiple antigens will influence the prevalence, diversity and evolution of influenza A virus (IAV) in avian populations where the vast subtype diversity is maintained. To investigate how initial infection influences the outcome of later infections with homologous or heterologous IAV subtypes and how viruses interact through host immune responses; we carried out experimental infections in mallard ducks (Anas platyrhynchos). Mallards were pre-challenged with an H3N8 low-pathogenic IAV and were divided into six groups. At five weeks post H3N8 inoculation, each group was challenged with a different IAV subtype or the same H3N8. Two additional pre-challenged groups were inoculated with the homologous H3N8 virus at weeks 11 and 15 after pre-challenge to evaluate the duration of protection, which showed that mallards were still resistant to re-infection after 15 weeks. There was a significant reduction in shedding for all pre-challenged groups compared to controls and the outcome of the heterologous challenges varied according to hemagglutinin (HA) phylogenetic relatedness between the viruses used. There was a boost in the H3 antibody titer after re-infection with H4N5, which is consistent with original antigenic sin or antigenic seniority and suggest a putative strategy of virus evasion. These results imply strong competition between related subtypes that could regulate IAV subtype population dynamics in nature. Collectively, we provide new insights into within-host IAV complex interactions as drivers of IAV antigenic diversity that could allow the circulation of multiple subtypes in wild ducks.Author summaryMany features of pathogen diversification remain poorly explored although host immunity is recognized as a major driver of pathogen evolution. Influenza A viruses (IAVs) can infect many avian and mammalian hosts, but while few IAV subtypes circulate in human populations, subtype diversity is extensive in wild bird populations. How do these subtypes coexist in wild avian populations and do they compete within these natural host populations? Here we experimentally challenged mallard ducks with different IAVs to study how an initial infection with H3N8 determines the outcome of later infections (duration of infection and virus load) and antibody responses. There was complete protection to re-infection with the same H3N8 virus based on virus isolation. In addition, there was partial protection induced by H3N8 pre-challenge to other subtypes and development of heterosubtypic immunity indicated by shorter infections and reduction in viral load compared to controls. This indicates that subtype dynamics in the host population are not independent. Amongst H3N8 pre-challenged groups, the highest protection was conferred to the H4N5 subtype which was most genetically related to H3N8. The H4N5 challenge also induced an increase in H3 antibody levels and evidence for antigenic seniority. Thus, previous infections with IAV can influence the outcome of subsequent infection with different IAV subtypes. Results not only have relevance to understanding naturally occurring subtype diversity in wild avian populations but also in understanding potential outcomes associated with introduction of novel viruses such as highly pathogenic IAV H5 viruses in wild bird populations.Author contributionsConceived and designed the experiments: NLM, DES. Performed the experiments: NLM, JDB, AF, DC, MF, DES. Contributed reagents/materials/analysis tools: NLM, JB, AF, RLP, DES. Analyzed the data: NLM, DES. Wrote the paper: NLM, JDB, AF, RLP, DC, MF, DES

scholarly journals Emergence of influenza A viruses

2001 ◽  
Vol 356 (1416) ◽  
pp. 1817-1828 ◽  
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.

Monitoring of influenza A viruses in wild bird populations in Kazakhstan in 2002-2009

2016 ◽  
Vol 162 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Aidyn Kydyrmanov ◽  
M. Sayatov ◽  
K. Karamendin ◽  
K. Zhumatov ◽  
S. Asanova ◽  
...  
Keyword(s):  
Influenza A ◽  
Wild Bird ◽  
Influenza A Viruses ◽  
Bird Populations

Pathogens from Wild Birds at the Wildlife–Agriculture Interface

2021 ◽  
pp. 207-228
Author(s):  
Alan B. Franklin ◽  
Sarah N. Bevins ◽  
Susan A. Shriner
Keyword(s):  
Disease Ecology ◽  
Influenza A ◽  
Wild Birds ◽  
Avian Species ◽  
Influenza A Viruses ◽  
Agricultural Health ◽  
Bird Populations ◽  
Food Borne ◽  
Global Movement ◽  
Agricultural Operations

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.

scholarly journals Molecular Basis for the Generation in Pigs of Influenza A Viruses with Pandemic Potential

1998 ◽  
Vol 72 (9) ◽  
pp. 7367-7373 ◽  
Author(s):  
Toshihiro Ito ◽  
J. Nelson S. S. Couceiro ◽  
Sørge Kelm ◽  
Linda G. Baum ◽  
Scott Krauss ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Structural Basis ◽  
Human Populations ◽  
Influenza A Viruses ◽  
Human Virus ◽  
Surface Receptors ◽  
Virus Receptors ◽  
Avian Influenza A Virus

ABSTRACT Genetic and biologic observations suggest that pigs may serve as “mixing vessels” for the generation of human-avian influenza A virus reassortants, similar to those responsible for the 1957 and 1968 pandemics. Here we demonstrate a structural basis for this hypothesis. Cell surface receptors for both human and avian influenza viruses were identified in the pig trachea, providing a milieu conducive to viral replication and genetic reassortment. Surprisingly, with continued replication, some avian-like swine viruses acquired the ability to recognize human virus receptors, raising the possibility of their direct transmission to human populations. These findings help to explain the emergence of pandemic influenza viruses and support the need for continued surveillance of swine for viruses carrying avian virus genes.

scholarly journals Complete Coding Sequences of One H9 and Three H7 Low-Pathogenic Influenza Viruses Circulating in Wild Birds in Belgium, 2009 to 2012

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Steven Van Borm ◽  
Toon Rosseel ◽  
Sylvie Marché ◽  
Mieke Steensels ◽  
Didier Vangeluwe ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Illumina Sequencing ◽  
Viral Genome ◽  
Influenza A ◽  
Wild Bird ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Bird Population ◽  
Coding Sequences ◽  
Wild Waterfowl

The complete coding sequences of four avian influenza A viruses (two H7N7, one H7N1, and one H9N2) circulating in wild waterfowl in Belgium from 2009 to 2012 were determined using Illumina sequencing. All viral genome segments represent viruses circulating in the Eurasian wild bird population.

scholarly journals The enigma of the apparent disappearance of Eurasian highly pathogenic H5 clade 2.3.4.4 influenza A viruses in North American waterfowl

2016 ◽  
Vol 113 (32) ◽  
pp. 9033-9038 ◽  
Author(s):  
Scott Krauss ◽  
David E. Stallknecht ◽  
Richard D. Slemons ◽  
Andrew S. Bowman ◽  
Rebecca L. Poulson ◽  
...  
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
Influenza A ◽  
Wild Bird ◽  
Animal Health ◽  
The United States ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Highly Pathogenic

One of the major unresolved questions in influenza A virus (IAV) ecology is exemplified by the apparent disappearance of highly pathogenic (HP) H5N1, H5N2, and H5N8 (H5Nx) viruses containing the Eurasian hemagglutinin 2.3.4.4 clade from wild bird populations in North America. The introduction of Eurasian lineage HP H5 clade 2.3.4.4 H5N8 IAV and subsequent reassortment with low-pathogenic H?N2 and H?N1 North American wild bird-origin IAVs in late 2014 resulted in widespread HP H5Nx IAV infections and outbreaks in poultry and wild birds across two-thirds of North America starting in November 2014 and continuing through June 2015. Although the stamping out strategies adopted by the poultry industry and animal health authorities in Canada and the United States—which included culling, quarantining, increased biosecurity, and abstention from vaccine use—were successful in eradicating the HP H5Nx viruses from poultry, these activities do not explain the apparent disappearance of these viruses from migratory waterfowl. Here we examine current and historical aquatic bird IAV surveillance and outbreaks of HP H5Nx in poultry in the United States and Canada, providing additional evidence of unresolved mechanisms that restrict the emergence and perpetuation of HP avian influenza viruses in these natural reservoirs.

scholarly journals Novel real-time PCR-based patho- and phylotyping of potentially zoonotic avian influenza A subtype H5 viruses at risk of incursion into Europe in 2017

2017 ◽  
Vol 22 (1) ◽  
Author(s):  
Mahmoud M Naguib ◽  
Annika Graaf ◽  
Andrea Fortin ◽  
Christine Luttermann ◽  
Ulrich Wernery ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Real Time ◽  
Influenza A ◽  
Wild Bird ◽  
Reaction Times ◽  
Highly Pathogenic ◽  
Bird Populations ◽  
Western Africa ◽  
Speed Up ◽  
Development And Validation

Since November 2016, Europe witnesses another wave of incursion of highly pathogenic avian influenza (HPAI) A(H5) viruses of the Asian origin goose/Guangdong (gs/GD) lineage. Infections with H5 viruses of clade 2.3.4.4b affect wild bird and poultry populations. H5 viruses of clades 2.2, 2.3.1.2c and 2.3.4.4a were detected previously in Europe in 2006, 2010 and 2014. Clades 2.2.1.2 and 2.3.2.1.c are endemic in Egypt and Western Africa, respectively and have caused human fatalities. Evidence exists of their co-circulation in the Middle East. Subtype H5 viruses of low pathogenicity (LPAI) are endemic in migratory wild bird populations. They potentially mutate into highly pathogenic phenotypes following transmission into poultry holdings. However, to date only the gs/GD H5 lineage had an impact on human health. Rapid and specific diagnosis marks the cornerstone for control and eradication of HPAI virus incursions. We present the development and validation of five real-time RT-PCR assays (RT-qPCR) that allow sequencing-independent pathotype and clade-specific distinction of major gs/GD HPAI H5 virus clades and of Eurasian LPAI viruses currently circulating. Together with an influenza A virus-generic RT-qPCR, the assays significantly speed up time-to-diagnosis and reduce reaction times in a OneHealth approach of curbing the spread of gs/GD HPAI viruses.

Influenza Recycling and Secular Trends in Mortality and Natality

2009 ◽  
Vol 15 (S1) ◽  
pp. 123-150 ◽  
Author(s):  
Maria Inês Reinert Azambuja
Keyword(s):  
Influenza A ◽  
Population Aging ◽  
Secular Trends ◽  
Human Populations ◽  
Birth Cohorts ◽  
Influenza A Viruses ◽  
The Past ◽  
Epidemiologic Evidence ◽  
Period Effects ◽  
Secular Variations

ABSTRACTSecular variations in longevity and in population aging are of huge interest to actuaries. It is shown here that temporal changes in mortality and natality accompany the recycling of influenza A viruses i.e., the re-exposure of human populations, from time to time, to influenza A viruses antigenically similar to viruses (H1, H2, H3) that circulated in the past. Mortality (and natality) change as birth cohorts (whole population and maternal) with specific types and levels of vulnerability to influenza A re-infections, acquired through early-life effects of infection with one (period-specific) influenza A sub-type, course through subsequent influenza A environments over time. Epidemiologic evidence of association between secular trends in mortality (and natality) and interactions between birth-cohort and period effects of influenza A circulation is presented both for the U.K. and the U.S. New interpretations to several epidemiologic and demographic observations follow from this finding.

scholarly journals Systemic infection with highly pathogenic H5N8 of avian origin produces encephalitis and mortality in wild mammals at a UK rehabilitation centre

2021 ◽  
Author(s):  
Tobias Floyd ◽  
Ashley C Banyard ◽  
Fabian ZX Lean ◽  
Alexander MP Byrne ◽  
Edward Fullick ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Wild Bird ◽  
Influenza A Viruses ◽  
Rehabilitation Centre ◽  
Highly Pathogenic ◽  
Wild Mammals ◽  
Domestic Poultry ◽  
Avian Origin ◽  
The Impact

Europe has experienced extensive outbreaks of highly pathogenic avian influenza (HPAI) during the autumn/winter 2020/21 season. These avian influenza A viruses are highly transmissible and have infected over 1000 commercial and backyard poultry premises in Europe in this period causing high mortality. The impact on wild bird populations has also been significant, with over 400 detections in at least 47 different species reported across Europe as being positive with the H5N8 virus. Although different H5Nx combinations within the H5 clade 2.3.4.4b have been detected, the H5N8 subtype has predominated both in wild birds and domestic poultry outbreaks. In the UK there have been 22 outbreaks of H5N8 in domestic poultry and captive birds and more than 300 wild bird detections involving H5N8 over the autumn/winter 2020/21 period to April 2021. Here we detail the series of events surrounding the detection of an H5N8 influenza A virus of avian origin in five swans, a fox and three seals in a wildlife rehabilitation centre.

scholarly journals Novel Reassortant Avian Influenza A(H3N8) Virus Isolated from a Wild Bird in Jiangxi, China

2019 ◽  
Vol 8 (46) ◽  
Author(s):  
Ruiyun Li ◽  
Tao Zhang ◽  
Jian Xu ◽  
Jianyu Chang ◽  
Bing Xu
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Wild Bird ◽  
Poyang Lake ◽  
Phylogenetic Analyses ◽  
H3n8 Virus

Here, we report the detection of a reassortant avian influenza A(H3N8) virus isolated from a wild bird in Poyang Lake, Jiangxi, China, in 2014. Phylogenetic analyses indicated that this virus is most likely derived from the Eurasian-origin H3Ny and HxN8 viruses and two strains endemic to China, namely, H5N1 and H5N6.

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