Interspecies and intraspecies transmission of influenza A viruses: viral, host and environmental factors

2010 ◽  
Vol 11 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Hadi M. Yassine ◽  
Chang-Won Lee ◽  
Renukaradhya Gourapura ◽  
Yehia M. Saif
Keyword(s):  
Influenza A ◽  
Mammalian Species ◽  
Viral Proteins ◽  
Interspecies Transmission ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Enveloped Viruses ◽  
Host System ◽  
Specific Host ◽  
The Family

AbstractInfluenza A viruses are enveloped viruses belonging to the familyOrthomyxoviridaethat encompasses four more genera: Influenza B, Influenza C, Isavirus and Thogotovirus. Type A viruses belong to the only genus that is highly infectious to a variety of mammalian and avian species. They are divided into subtypes based on two surface glycoproteins, the hemagglutinin (HA) and neuraminidase (NA). So far, 16 HA and 9 NA subtypes have been identified worldwide, making a possible combination of 144 subtypes between both proteins. Generally, individual viruses are host-specific, however, interspecies transmission of influenza A viruses is not uncommon. All of the HA and NA subtypes have been isolated from wild birds; however, infections in humans and other mammalian species are limited to a few subtypes. The replication of individual influenza A virus in a specific host is dependent on many factors including, viral proteins, host system and environmental conditions. In this review, the key findings that contribute to the transmission of influenza A viruses amongst different species are summarized.

Influenza virus proteins as factors involved in interspecies transmission

2014 ◽  
Vol 17 (4) ◽  
Author(s):  
I.M. Góra ◽  
W. Rożek ◽  
J.F. Żmudziński
Keyword(s):  
Influenza Virus ◽  
Host Response ◽  
Influenza A ◽  
Viral Proteins ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Specific Host ◽  
Viral Genes ◽  
Interspecies Barrier

AbstractInfluenza A viruses cause recurrent epidemics and global pandemics. One of the unique features of influenza virus is the ability to overcome interspecies barrier. Reassortment of viral genes and the accumulation of mutations contribute to the emergence of new influenza virus variants. The replication of influenza A virus in a specific host depends on many factors e.g. activity of viral proteins, host response system and environmental conditions. In this review the role of viral proteins as a condition for crossing the species barriers is discussed.

scholarly journals Airborne Transmission of Avian Origin H9N2 Influenza A Viruses

2021 ◽  
Author(s):  
C. Joaquín Cáceres ◽  
Daniela S. Rajao ◽  
Daniel R. Perez
Keyword(s):  
Influenza A ◽  
Mammalian Species ◽  
World Health ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Highly Pathogenic ◽  
Zoonotic Infections ◽  
The World ◽  
Avian Origin ◽  
Health Organization

Influenza A viruses (IAV) are widespread viruses affecting avian and mammalian species worldwide. Outbreaks of IAV in poultry are usually associated with substantial morbidity and mortality, significantly affecting the poultry industry and food security. IAVs from avian species can be transmitted to mammals including humans and, thus, they are of inherent pandemic concern. Most of the efforts to understand the pathogenicity and transmission of avian origin IAVs have been focused on H5 and H7 subtypes due to their highly pathogenic phenotype in poultry. However, IAV of the H9 subtype that circulate endemically in poultry flocks in some regions of the world have also been associated with cases of zoonotic infections. As a result, the World Health Organization includes avian origin H9N2 IAV among the top in the list of IAVs of pandemic concern. In this review, we discuss the interspecies transmission of H9N2 between avian and mammalian species and the molecular factors that are thought relevant for this spillover. Additionally, we discuss factors that have been associated with the ability of these viruses to transmit through the respiratory route in mammalian species.

scholarly journals The Development and Use of Reporter Influenza B Viruses

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 736 ◽  
Author(s):  
Rebekah E. Dumm ◽  
Nicholas S. Heaton
Keyword(s):  
Immune Responses ◽  
Host Response ◽  
Influenza A ◽  
Genetically Modified ◽  
Viral Proteins ◽  
Influenza Viruses ◽  
Influenza B ◽  
Human Influenza ◽  
Influenza A Viruses ◽  
Viral Spread

Influenza B viruses (IBVs) are major contributors to total human influenza disease, responsible for ~1/3 of all infections. These viruses, however, are relatively less studied than the related influenza A viruses (IAVs). While it has historically been assumed that the viral biology and mechanisms of pathogenesis for all influenza viruses were highly similar, studies have shown that IBVs possess unique characteristics. Relative to IAV, IBV encodes distinct viral proteins, displays a different mutational rate, has unique patterns of tropism, and elicits different immune responses. More work is therefore required to define the mechanisms of IBV pathogenesis. One valuable approach to characterize mechanisms of microbial disease is the use of genetically modified pathogens that harbor exogenous reporter genes. Over the last few years, IBV reporter viruses have been developed and used to provide new insights into the host response to infection, viral spread, and the testing of antiviral therapeutics. In this review, we will highlight the history and study of IBVs with particular emphasis on the use of genetically modified viruses and discuss some remaining gaps in knowledge that can be addressed using reporter expressing IBVs.

scholarly journals Influenza A viruses of avian origin circulating in pigs and other mammals.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Kinga Urbaniak ◽  
Andrzej Kowalczyk ◽  
Iwona Markowska-Daniel
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Mammalian Species ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Species Barrier ◽  
New Host

Influenza A viruses (IAVs) are zoonotic agents, capable of crossing the species barriers. Nowadays, they still constitute a great challenge worldwide. The natural reservoir of all influenza A viruses are wild aquatic birds, despite the fact they have been isolated from a number of avian and mammalian species, including humans. Even when influenza A viruses are able to get into another than waterfowl population, they are often unable to efficiently adapt and transmit between individuals. Only in rare cases, these viruses are capable of establishing a new lineage. To succeed a complete adaptation and further transmission between species, influenza A virus must overcome a species barrier, including adaptation to the receptors of a new host, which would allow the virus-cell binding, virus replication and, then, animal-to-animal transmission. For many years, pigs were thought to be intermediate host for adaptation of avian influenza viruses to humans, because of their susceptibility to infection with both, avian and human influenza viruses, which supported hypothesis of pigs as a 'mixing vessel'. In this review, the molecular factors necessary for interspecies transmission are described, with special emphasis on adaptation of avian influenza viruses to the pig population. In addition, this review gives the information about swine influenza viruses circulating around the world with special emphasis on Polish strains.

scholarly journals Influenza A Virus Neuraminidase Limits Viral Superinfection

2008 ◽  
Vol 82 (10) ◽  
pp. 4834-4843 ◽  
Author(s):  
I-Chueh Huang ◽  
Wenhui Li ◽  
Jianhua Sui ◽  
Wayne Marasco ◽  
Hyeryun Choe ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Viral Proteins ◽  
Neuraminidase Inhibitors ◽  
Influenza A Viruses ◽  
Oseltamivir Carboxylate ◽  
Enveloped Viruses ◽  
Cellular Expression ◽  
Viral Genes ◽  
H3n2 Influenza

ABSTRACT Enveloped viruses use multiple mechanisms to inhibit infection of a target cell by more than one virion. These mechanisms may be of particular importance for the evolution of segmented viruses, because superinfection exclusion may limit the frequency of reassortment of viral genes. Here, we show that cellular expression of influenza A virus neuraminidase (NA), but not hemagglutinin (HA) or the M2 proton pump, inhibits entry of HA-pseudotyped retroviruses. Cells infected with H1N1 or H3N2 influenza A virus were similarly refractory to HA-mediated infection and to superinfection with a second influenza A virus. Both HA-mediated entry and viral superinfection were rescued by the neuraminidase inhibitors oseltamivir carboxylate and zanamivir. These inhibitors also prevented the removal of α-2,3- and α-2,6-linked sialic acid observed in cells expressing NA or infected with influenza A viruses. Our data indicate that NA alone among viral proteins limits influenza A virus superinfection.

scholarly journals An evaluation of the InDevR FluChip-8G insight microarray assay in characterizing influenza a viruses

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Emily S. Bailey ◽  
Xinye Wang ◽  
Mai-juan Ma ◽  
Guo-lin Wang ◽  
Gregory C. Gray
Keyword(s):  
Influenza A ◽  
Influenza Viruses ◽  
Time Range ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Laboratory Methods ◽  
Duke University ◽  
Multiple Viral Strains ◽  
Rapid Characterization

AbstractInfluenza viruses are an important cause of disease in both humans and animals, and their detection and characterization can take weeks. In this study, we sought to compare classical virology techniques with a new rapid microarray method for the detection and characterization of a very diverse, panel of animal, environmental, and human clinical or field specimens that were molecularly positive for influenza A alone (n = 111), influenza B alone (n = 3), both viruses (n = 13), or influenza negative (n = 2) viruses. All influenza virus positive samples in this study were first subtyped by traditional laboratory methods, and later evaluated using the FluChip-8G Insight Assay (InDevR Inc. Boulder, CO) in laboratories at Duke University (USA) or at Duke Kunshan University (China). The FluChip-8G Insight multiplexed assay agreed with classical virologic techniques 59 (54.1%) of 109 influenza A-positive, 3 (100%) of the 3 influenza B-positive, 0 (0%) of 10 both influenza A- and B-positive samples, 75% of 24 environmental samples including those positive for H1, H3, H7, H9, N1, and N9 strains, and 80% of 22 avian influenza samples. It had difficulty with avian N6 types and swine H3 and N2 influenza specimens. The FluChip-8G Insight assay performed well with most human, environmental, and animal samples, but had some difficulty with samples containing multiple viral strains and with specific animal influenza strains. As classical virology methods are often iterative and can take weeks, the FluChip-8G Insight Assay rapid results (time range 8 to 12 h) offers considerable time savings. As the FluChip-8G analysis algorithm is expected to improve over time with addition of new subtypes and sample matrices, the FluChip-8G Insight Assay has considerable promise for rapid characterization of novel influenza viruses affecting humans or animals.

scholarly journals Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

2018 ◽  
Vol 3 (2) ◽  
pp. 1-2
Author(s):  
Bishnu Prasad Upadhyay
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Winter Season ◽  
Emerging Infectious Diseases ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
New Variant ◽  
Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

scholarly journals Modulation of Innate Immune Responses by the Influenza A NS1 and PA-X Proteins

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 708 ◽  
Author(s):  
Aitor Nogales ◽  
Luis Martinez-Sobrido ◽  
David Topham ◽  
Marta DeDiego
Keyword(s):  
Immune Responses ◽  
Influenza A ◽  
Defense Mechanisms ◽  
Synergistic Effects ◽  
Viral Proteins ◽  
Economic Problem ◽  
Innate Immune ◽  
Host Protein ◽  
Innate Immune Responses ◽  
Influenza A Viruses

Influenza A viruses (IAV) can infect a broad range of animal hosts, including humans. In humans, IAV causes seasonal annual epidemics and occasional pandemics, representing a serious public health and economic problem, which is most effectively prevented through vaccination. The defense mechanisms that the host innate immune system provides restrict IAV replication and infection. Consequently, to successfully replicate in interferon (IFN)-competent systems, IAV has to counteract host antiviral activities, mainly the production of IFN and the activities of IFN-induced host proteins that inhibit virus replication. The IAV multifunctional proteins PA-X and NS1 are virulence factors that modulate the innate immune response and virus pathogenicity. Notably, these two viral proteins have synergistic effects in the inhibition of host protein synthesis in infected cells, although using different mechanisms of action. Moreover, the control of innate immune responses by the IAV NS1 and PA-X proteins is subject to a balance that can determine virus pathogenesis and fitness, and recent evidence shows co-evolution of these proteins in seasonal viruses, indicating that they should be monitored for enhanced virulence. Importantly, inhibition of host gene expression by the influenza NS1 and/or PA-X proteins could be explored to develop improved live-attenuated influenza vaccines (LAIV) by modulating the ability of the virus to counteract antiviral host responses. Likewise, both viral proteins represent a reasonable target for the development of new antivirals for the control of IAV infections. In this review, we summarize the role of IAV NS1 and PA-X in controlling the antiviral response during viral infection.

scholarly journals Influenza A and B viruses in the population of Vojvodina, Serbia

2014 ◽  
Vol 66 (1) ◽  
pp. 43-50 ◽  
Author(s):  
J. Radovanov ◽  
V. Milosevic ◽  
I. Hrnjakovic ◽  
V. Petrovic ◽  
M. Ristic ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Infections ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Nasopharyngeal Swab ◽  
Influenza B ◽  
Influenza A Viruses ◽  
B Virus ◽  
Life Threatening ◽  
Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

scholarly journals Epidemiological and virological assessment of influenza activity in Europe during the winter 2005-2006

2007 ◽  
Vol 12 (9) ◽  
pp. 11-12 ◽  
Author(s):  
A Meijer ◽  
T J Meerhoff ◽  
L. E. Meuwissen ◽  
J Van Der Velden ◽  
W J Paget ◽  
...  
Keyword(s):  
Influenza A ◽  
New Caledonia ◽  
Influenza B Virus ◽  
Random Pattern ◽  
Clinical Activity ◽  
Influenza B ◽  
Influenza A Viruses ◽  
B Virus ◽  
Influenza Activity ◽  
Spread Pattern

Influenza activity in Europe during the winter 2005-2006 started late January - early February 2006 and first occurred in the Netherlands, France, Greece and England. Subsequently, countries were affected in a random pattern across Europe and the period of influenza activity lasted till the end of April. In contrast to the winter seasons in the period 2001-2005, no west-east pattern was detected. In 12 out of 23 countries, the consultation rates for influenza-like illness or acute respiratory infection in the winter 2005-2006 were similar or higher than in the winter 2004-2005, despite a dominance of influenza B viruses that normally cause milder disease than influenza A viruses. In the remaining 11 countries the consultation rates were lower to much lower than in the winter 2004-2005. The highest consultation rates were usually observed among children aged 0-14. The circulating influenza virus types and subtypes were distributed heterogeneously across Europe. Although the figures for total virus detections in Europe indicated a predominance of influenza B virus (58% of all virus detections), in many countries influenza B virus was predominant only early in the winter, whilst later there was a marked increase in influenza A virus detections. Among the countries where influenza A viruses were co-dominant with B viruses (9/29) or were predominant (4/29), the dominant influenza A subtype was H3 in seven countries and H1 in four countries. The vast majority of characterised influenza B viruses (90%) were similar to the B/Victoria/2/87 lineage of influenza B viruses that re-emerged in Europe in the winter 2004-2005 but were not included in the vaccine for the influenza season 2005-2006. This might help to explain the dominance of influenza B viruses in many countries in Europe during the winter 2005-2006. The influenza A(H3) and A(H1) viruses were similar to the reference strains included in the 2005-2006 vaccine, A/California/7/2004 (H3N2) and A/New Caledonia/20/99 (H1N1), respectively. In conclusion, the 2005-2006 influenza epidemic in Europe was characterised by moderate clinical activity, a heterogeneous spread pattern across Europe, and a variable virus dominance by country, although an overall dominance of influenza B viruses that did not match the virus strain included in the vaccine was observed.

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