However, despite their obvious importance, the frequencies, patterns, and consequences of mutation, reassortment, and natural selection as they occur. The other option cross species transmission occurs when a virus jumps into a completely new type of host largely unrelated to its former one. C the emergence of cpv as an example of multiple mutations being required for a virus to adapt to a new host, after which the virus evolves within the recipient species. Phylodynamics of the emergence of influenza viruses after cross. Crossspecies transmission of avian influenza a h5n1 to. Evidence for cross species influenza a virus transmission within swine farms, china. Homologous recombination within viral structural proteins between coronaviruses from different hosts may be responsible for cross. This is a phenomenon known as crossspecies transmission cst. Intrahost dynamics of antiviral resistance in influenza a. Influenza a viruses iavs are a cause of respiratory disease in swine that can decrease pig performance, negatively affect health, and are sporadically transmitted to and from humans.
Influenza d virus in animal species in guangdong province. It has caused health concerns in places like indonesia where visitors at monkey temples can contract sfv. Crossspecies transmission and emergence of novel viruses. Panels a and b adapted from reference 60 with permission of aaas. The role of birds in crossspecies transmission and emergence of novel viruses such as avian influenza a viruses are discussed. In the last 20 years, china has witnessed several emerging viral diseases, including an avian influenza in 1997, 1 the severe acute respiratory syndrome sars in 2003, 2 and a severe fever with thrombocytopenia syndrome sfts in 2010. Canine influenza ah3n2 viruses are different from seasonal influenza ah3n2 viruses that spread annually in people.
Evidence for crossspecies influenza a virus transmission within swine farms, china. Cross species transmission of a novel adenovirus associated with a fulminant pneumonia outbreak in a new world monkey. Molecular tests revealed influenza d viruses of dok lineage widely circulating in farmed animal species in guangdong province, southern china. Influenza a viruses that typically infect and transmit among one animal species sometimes can cross over and cause illness in another species. Suppression of avian influenza transmission in genetically. Wild pigs are increasingly a potential veterinary and. These processes are also central to the host adaptation of newly emerging influenza viruses following cross species transmission and to the evolution of drug resistance in human populations. Linking to a nonfederal website does not constitute an endorsement by cdc or any of its employees of the sponsors or the information and products presented on the website.
However, in the early 1980s, the classical swine h1n1 strain was displaced by a new european enzootic swine iav strain, the eurasian, avianlike h1n1 h1 av n1 lineage 1c, probably after crossspecies transmission directly from birds to mammals. Influenza virus cross species transmission poses a continual threat to human health. No human infections with canine influenza have ever been reported. Although control of aiv infection in its wild aquatic bird reservoir is impractical, control of aiv in domesticated hosts is possible. During 2010, a swine influenza a reassortant virus, h1n2r, which caused mild clinical disease in pigs in the united kingdom, was isolated. For example, until 1998, only h1n1 viruses circulated widely in the u.
Identification and discovery of viruses using nextgeneration sequencing technology is a fastdeveloping area with potential wide application in clinical diagnostics, public health monitoring and. In addition, avian influenza viruses h5 and h7 can be further classified as low pathogenicity lp, lpai and high pathogenicity hp. Pr8 as well as two low pathogenic avian influenza viruses subtypes h4n6 and h6n1. Links with this icon indicate that you are leaving the cdc website the centers for disease control and prevention cdc cannot attest to the accuracy of a nonfederal website.
Simian foamy viruses sfv is an enzootic retrovirus that has high rates of crossspecies transmission and has been known to affect humans bitten by infected nhps. Interspecies transmission of influenza viruses cidrap. Interspecies transmission and receptor recognition of. Direct contact with infected poultry, or with surfaces and objects contaminated by their droppings, is the main route of transmission to humans. In most cases, humans come into contact with the animal itself, animal excreta, or animal parts e. Transmission of avian influenza a viruses between animals and. I mean maybe but i think it would be extraordinarily unlikely. Influenza species barriers can be categorized into virushost interactions occurring within individuals and hosthost interactions, either within or between species, that affect transmission. Flu researchers discover new mechanism for battling influenza. Since emerging in 1997, h5n1 avian influenza viruses aivs have caused 860 confirmed infections and 454 deaths in humans. Evidence for crossspecies influenza a virus transmission. Our understanding of influenza a virus transmission between humans and pigs is limited. The only other animal known to be susceptible to influenza b infection is the seal.
Interspecies and intraspecies transmission of influenza a. Crossspecies transmission of avian influenza h5n1 to humans thomas thacker, b. Human infections with highly pathogenic avian influenza ah5n1 virus occur through birdtohuman, possibly environmenttohuman and, very rarely, limited, nonsustained humantohuman transmission. Influenza a viruses have infected many different animals, including ducks, chickens, pigs, whales, horses, and seals. That kind of viral evolution is notoriously linked to severe emerging diseases like bird flu, hiv, ebola fever and sars. Influenza ah1n1pdm09 ph1n1 virus has become established in swine in the united kingdom and currently cocirculates with previously enzootic swine influenza a virus iav strains, including avianlike h1n1 and humanlike h1n2 viruses. Ma mj1, wang gl1, anderson bd2, bi zq34, lu b 5, wang xj 34, wang cx 6, chen sh 5, qian yh5, song sx34, li m6, lednicky ja7, zhao t1, wu mn1, cao wc1, gray gc289.
Canine influenza virus civ h3n2 is a virus of avian origin and was first reported in 2007. An mdckbased cell line expressing human bst2 was generated to study humanderived apuerto rico836 h1n1. The critical interspecies transmission barrier at the animal. Could antigenic drift cause changes in the influenza virus. We investigated the underlying ecologic and epidemiologic processes associated with this viral spread by performing a comparative genomic study using 268 fulllength. Who infection of farmed animals with the pandemic virus. This type of influenza mutates at a rate 23 times lower than type a and consequently is less genetically diverse, with only one influenza. A total of fourteen 8week old, specific pathogenfree rabbits were divided into three experimental groups. However, certain subtypes of influenza a virus are specific to certain species, except for birds, which are hosts to all known subtypes of influenza a viruses.
Crossspecies virus transmission and the emergence of new. The cross species infection can originate on farms or markets, where conditions foster mixing of pathogens, giving them opportunities to swap genes and gear up to infect and sometimes kill. Cross species transmission cst, also called interspecies transmission, host jump, or spillover, is the ability for a foreign virus, once introduced into an individual of a new host species, to infect that individual and spread throughout a new host population. A metagenomic analysis of pandemic influenza a 2009 h1n1 infection in patients from north america.
This facilitates successful crossspecies transmission because only a small number of advantageous mutations are required. Influenza b virus is almost exclusively a human pathogen, and is less common than influenza a. Transmission of avian influenza virus h3n2 to dogs. The novel avian viruses identified between 2012 and 2014 are summarized. The emergence of the pandemic h1n1 2009 influenza virus reminded us of the importance of cross species transmission of influenza viruses. Transmission of avian influenza a viruses between animals. Viruses would rather jump to new hosts than evolve with. Human infection with h5n1 influenza viruses most often occurs after the infection of poultry on farms or in live bird markets, allowing viruses of wild birds to gain.
A cloudcompatible bioinformatics pipeline for ultrarapid. The interspecies transmission of influenza a virus sciencedirect. The emergence of h1n1 has shown the necessity for developing more biologically complex models that can provide a comprehensive understanding of strains that arise due to cross species transmission. Deadly human diseases including hiv aids, swine flu and rabies are infectious diseases where the viruses have jumped from one animal species into another and now infect humans too. In particular, we found high levels of influenza d virus infection in goats and pigs.
Influenza viruses from waterbirds can cross the species barrier and infect numerous other species see fig. In fact, this is why smallpox is the only viral disease we have truly eradicated, and one of the few we can reasonably hope to truly eradicate. Infections in swine concern has traditionally focused on swine, which are susceptible to infections from human and avian influenza viruses as well as swine influenza viruses. For example, the repeated evolution of the same amino acid changes following the cross species transmission of avian influenza virus to humans. Interspecies transmission of reassortant swine influenza a. In this study, the possibility of cross species infection with swine hev3 was investigated using rabbits. No evidence of dogtodog transmission or virus persistence in dogs was found. Pdf crossspecies virus transmission and the emergence of. More studies are needed, but krug believes new therapeutics could be designed to block the ns1 protein produced by the flu virus, hobbling its ability to evade the human immune system. The spillover of avian influenza a viruses into humans often leads to pandemics with high mortality. Nucleotide sequence of the virus from dogs was identical to that from horses. Beginning in 2015, we used a one health approach and serial sampling to prospectively study 299 swine workers and 100. A recent example of birdtoanimal transmission is the mortality amongst harbour seals phoca vitulina of the northeuropean coastal waters following infection with the lpai h10n7 virus 14, 15.
There are two different influenza a dog flu viruses. Examples include covid19, sars, ebola, swine flu, rabies, and avian influenza. The concept of pathogen augmentation is introduced. Host species barriers to influenza virus infections science. Steps involved in the transfer of viruses to new hosts include contact between the virus and the host, infection of an initial. The majority of these crossspecies transmissions actually ends up as.
Cross species disease transmission between wildlife, domestic animals and humans is an increasing threat to public and veterinary health. Identification of interferon stimulated genes that restrict cross species transmission of influenza a virus the grey lab has developed libraries of interferon ifn stimulated genes isgs from pigs and chickens to examine the factors involved in the cross species transmission of influenza a. The phylogenomics of evolving virus virulence nature. Transmission of an entire avian influenza virus to an unrelated mammalian species. Recent epidemic diseases of animal origin are the 19181919 influenza pandemic, and the acquired. Among swine, reassortment of influenza virus genes from birds, pigs, and humans could generate influenza viruses with pandemic potential. Viruses free fulltext crossspecies transmission of. In contrast, there is significant interspecies transmission of influenza viruses from.
While most influenza a viruses circulating in mammals preferentially infect a single species, cross species transmission is known to occur. Transmission of avian influenza virus to a new mammalian species is of great concern, because it potentially allows the virus to adapt to a new mammalian host, cross new species barriers, and. Understanding this process is the key to predicting and preventing future outbreaks. Evidence for crossspecies influenza a virus transmission within. This article describes the study design and methods being used to assess influenza a transmission between swine workers and pigs. A comprehensive study of crossspecies transmission and interregional migration would provide insights into. Crossspecies transmission potential between wild pigs. The avian influenza virus pa segment mediates strain. Request pdf interspecies and intraspecies transmission of influenza a viruses. State key laboratory of pathogen and biosecurity, beijing institute of microbiology and epidemiology, china. Crossing the bridge many infectious diseases cross the species barrier. Cross species transmission of influenza viruses may occur directly or be facilitated by intermediate host species that amplify and diversify virus populations, notably domestic chickens, ducks, and pigs. Transmission of avian influenza a virus to a new mammalian species is of great concern, because it potentially allows the virus to adapt to a new mammalian host, cross new species barriers, and acquire pandemic potential.
Transmission of avian influenza a viruses between animals and people. Cross species avian flu transmission varies with subtype in an experiment involving the use of an imitation barnyard, ducks readily transmitted avian influenza viruses to other bird and animal species, but transmission varied among virus subtypes, according to a. Influenza viruses from waterbirds can cross the species barrier and infect. Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. Influenza viruses appear to interact with bst2, raising the possibility that bst2 may be a barrier for cross species transmission. The goal of this training module is to describe the process of and the occurrence of interspecies transmission of influenza viruses. Quantifying withinhost diversity of h5n1 influenza. Hepatitis e virus hev is a quasienveloped, positivesense single stranded rna virus. Network analysis of hostvirus communities in bats and rodents reveals determinants of crossspecies transmission pdf, ecology letters.
Eurasia highly pathogenic avian influenza virus hpaiv h5 clade 2. Influenza virus illustrates the interaction of factors that limit the transmission and subsequent establishment of an infection in a novel host species. Transmission dynamics of highly pathogenic avian influenza. Although unsubstantiated, in view of the possibility of such a theoretical mechanism for cross species transmission and the recently confirmed diagnoses in britain of clinical respiratory disease in nonvaccinated horses caused by h3n8 eiv that is closely related to newmarket503 vr, june 16, 2007, vol 160, p 851, we advise that colleagues. Sawyer and meyerson are now looking to further investigate the role trim25 plays in cross species transmission of influenza. Identification of interferon stimulated genes that. During the 2007 equine influenza outbreak in australia, respiratory disease in dogs in close contact with infected horses was noted. Humans with acute infection might also be a source of infection for swine production units.
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