Notably, avian influenza A(H5N1), A(H5N6), A(H7N9), and A(H9N2) viruses, and swine-origin variant viruses A(H1N1)v, A(H1N2)v, and A(H3N2)v have resulted in novel human influenza infections globally. (cdc.gov)
Eurasian "avian-like" (EA) swine H1N1 and "human-like" H1N2, highlighting the importance of swine as adaptation host of avian to human IAVs. (bvsalud.org)
Nowadays, although of limited use, a trivalent vaccine, which include in its formulation H1N1, H3N2, and, H1N2 swine IAV (SIAV) subtypes, is one of the most applied strategies to reduce SIAV circulation in farms. (bvsalud.org)
Three influenza A virus (IAV) subtypes circulate globally in swine: H1N1, H1N2 and H3N2. (cdc.gov)
Subtyping revealed 34 (54.8%) viruses of the H1N1 subtype, comprising 30 (48.4%) H1avN1av viruses, 3 (4.8%) pH1N1av viruses, and 1 (1.6%) H1huN1av virus. (cdc.gov)
Neuraminidase2
Influenza A viruses are classified into subtypes based on the surface proteins hemagglutinin (HA) and neuraminidase (NA). (cdc.gov)
Within each subtype, multiple hemagglutinin (HA) and neuraminidase (NA) lineages or clades cocirculate. (cdc.gov)
Swine5
An influenza virus that normally circulates in swine (but not people) but then is detected in a person is called a variant virus and is denoted with the letter v. (cdc.gov)
Infected swine shed the virus in nasal secretions and can transmit viruses to humans in the same way seasonal influenza viruses spread among people. (cdc.gov)
During 2019–2021, we isolated 62 swine influenza A viruses in Belgium and the Netherlands. (cdc.gov)
these processes resulted in multiple genotypes with gene segments of swine, avian, and human origin. (cdc.gov)
From those samples, we obtained 62 swine IAVs by virus isolation in MDCK cells. (cdc.gov)
Novel influenza refers to viruses with a subtype different from seasonal influenza, and usually is caused by influenza A viruses that circulate among animals. (cdc.gov)
H5N16
Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus which can cause illness in humans and many other species. (wikipedia.org)
According to the World Health Organization (WHO) and the United Nations Food and Agriculture Organization, H5N1 pathogenicity is gradually continuing to rise in endemic areas, but the avian influenza disease situation in farmed birds is being held in check by vaccination, and there is "no evidence of sustained human-to-human transmission" of the virus. (wikipedia.org)
HPAI A(H5N1) is considered an avian disease, although there is some evidence of limited human-to-human transmission of the virus. (wikipedia.org)
citation needed] Due to the high lethality and virulence of HPAI A(H5N1), its endemic presence, its increasingly large host reservoir, and its significant ongoing mutations, in 2006, the H5N1 virus has been regarded to be the world's largest pandemic threat, and billions of dollars are being spent researching H5N1 and preparing for a potential influenza pandemic. (wikipedia.org)
H5N1 may cause more than one influenza pandemic, as it is expected to continue mutating in birds regardless of whether humans develop herd immunity to a future pandemic strain. (wikipedia.org)
Influenza is caused by infection of the respiratory tract with influenza viruses, RNA viruses of the Orthomyxovirus genus. (cdc.gov)
Influenza viruses spread from person to person, primarily through respiratory droplets (e.g., when an infected person coughs or sneezes near a susceptible person). (cdc.gov)
Most adults ill with influenza shed the virus in the upper respiratory tract and are infectious from the day before symptom onset to ≈5-7 days after symptom onset. (cdc.gov)
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a zoonotic virus able to infect humans and multiple nonhuman animal species. (bvsalud.org)
Cause illness in humans1
Influenza viruses are classified into 4 types: A, B, C, and D. Influenza A and B viruses commonly cause illness in humans and seasonal epidemics. (cdc.gov)
Infect2
Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people. (cdc.gov)
Those who are asymptomatic can still shed the virus and infect others. (cdc.gov)
20211
During the coronavirus disease 2019 pandemic in 2020 and 2021, there was a sharp decrease in global influenza activity. (cdc.gov)
IAVs1
Influenza A viruses (IAVs) are characterized by having a segmented genome, low proofreading polymerases, and a wide host range. (bvsalud.org)
Pandemic2
Experts have identified key events (creating new clades, infecting new species, spreading to new areas) marking the progression of an avian flu virus towards becoming pandemic, and many of those key events have occurred more rapidly than expected. (wikipedia.org)
At least 12 companies and 17 governments are developing prepandemic influenza vaccines in 28 different clinical trials that, if successful, could turn a deadly pandemic infection into a nondeadly one. (wikipedia.org)
Vaccines1
Protection provided by vaccines is not complete, allowing virus circulation, potentially favoring viral evolution. (bvsalud.org)
Humans5
A risk factor for contracting the virus is handling of infected poultry, but transmission of the virus from infected birds to humans has been characterized as inefficient. (wikipedia.org)
In general, humans who catch a humanized influenza A virus (a human flu virus of type A) usually have symptoms that include fever, cough, sore throat, muscle aches, conjunctivitis, and, in severe cases, breathing problems and pneumonia that may be fatal. (wikipedia.org)
Influenza A virus transmission from animals to humans is rare but possible. (cdc.gov)
Infected birds shed influenza virus in their droppings, mucus, and saliva, and transmission to humans can occur from direct contact with an animal (by touching an infected animal or by droplet spread) or contact with a sick animal's environment (by inhalation of airborne viruses or through fomite transmission). (cdc.gov)
Information about circulating seasonal viruses in various regions can be found on the Centers for Disease Control and Prevention (CDC) website or World Health Organization website. (cdc.gov)
Seasonal influenza viruses are rarely detected in blood or stool. (cdc.gov)
In subtropical and tropical regions, seasonal influenza epidemics follow a similar pattern, but influenza illnesses can occur throughout the year. (cdc.gov)
Human3
On September 29, 2005, David Nabarro, the newly appointed Senior United Nations System Coordinator for Avian and Human Influenza, warned the world that an outbreak of avian influenza could kill anywhere between 5 million and 150 million people. (wikipedia.org)
Influenza type C infections generally cause mild illness and are not thought to cause human influenza epidemics. (cdc.gov)
To date, American mink and white-tailed deer are the only species that led to extensive intraspecies transmission of SARS-CoV-2 after reverse zoonosis, leading to an efficient spread of the virus and subsequent animal-to-human transmission. (bvsalud.org)
Transmission1
Indirect transmission occurs when a person touches their face after touching a virus-contaminated surface (fomite). (cdc.gov)
Animals1
The nonsynonymous substitutions proportion found was greater in vaccinated animals suggesting that H1N2 SIAV was under positive selection in this scenario. (bvsalud.org)
Disease1
The global HPAI situation significantly improved in the first half of 2008, but the FAO reports that imperfect disease surveillance systems mean that occurrence of the virus remains underestimated and underreported. (wikipedia.org)
Identification2
Full-scale production of a vaccine that could prevent any illness at all from the strain would require at least three months after the virus's emergence to begin, but it is hoped that vaccine production could increase until one billion doses were produced by one year after the initial identification of the virus. (wikipedia.org)
The ever-changing diversity of influenza viruses and the identification of influenza D emphasize the need for more virus surveillance. (cdc.gov)
Risk1
The risk for influenza exposure during travel depends on the time of year and destination. (cdc.gov)
Areas1
the distribution of these viruses varies year to year and between geographic areas and time of year. (cdc.gov)
Epidemiology2
In this context, the currently available scientific data hold a high significance to unravel influenza virus epidemiology and evolution. (nih.gov)
We conducted an active influenza surveillance in the single pig slaughterhouse in Dakar to investigate the epidemiology and genetic characteristics of influenza A viruses (IAVs) and to provide serologic evidence of avian influenza virus (AIV) infection in pigs at interfaces with human populations in Senegal. (bvsalud.org)
Infection3
Influenza is caused by infection of the respiratory tract with influenza viruses, RNA viruses of the Orthomyxovirus genus. (cdc.gov)
Inappropriate heat-treated swine offal has previously been shown to be the source of swine-related influenza A virus infection in mink ( 10 , 11 ). (cdc.gov)
Emergence of new1
Swine serve as a "mixing vessel" for influenza virus reassortment and evolution which as a result may facilitate the emergence of new strains or subtypes of zoonotic potential. (nih.gov)
H9N21
Influenza H7N7 (54.3%) and H9N2 (53.6%) were the dominant avian subtypes detected in Senegalese pigs. (bvsalud.org)
Commonly1
Influenza viruses are classified into 4 types: A, B, C, and D. Influenza A and B viruses commonly cause illness in humans and seasonal epidemics. (cdc.gov)
Pigs3
For more information, see CDC's website What People Who Raise Pigs Need to Know about Influenza . (cdc.gov)
Hepatitis E virus (HEV) is a zoonotic virus for which pigs are the primary animal reservoir. (cdc.gov)
Year-round influenza activity was noted in pigs, with the highest incidence between June and September. (bvsalud.org)
Surveillance1
The global HPAI situation significantly improved in the first half of 2008, but the FAO reports that imperfect disease surveillance systems mean that occurrence of the virus remains underestimated and underreported. (wikipedia.org)
Genome2
It is a nonenveloped RNA virus with a positive-sense genome of ≈7.2 kb. (cdc.gov)
Influenza A viruses were diagnosed using RT-qPCR and a subset of positive samples for H3 and H1 subtypes were selected for full genome amplification and NGS sequencing. (bvsalud.org)
Infections2
Influenza type C infections generally cause mild illness and are not thought to cause human influenza epidemics. (cdc.gov)
and human IFN-α11 subtype exerts subtype-specific activation of NK cells to restrict retroviral infections 17 . (nature.com)
Potential1
Influenza virus due to its wide host range and zoonotic potential poses such a significant threat to public health. (nih.gov)
Type1
Type I IFNs in amniotes are noted for their single-exon (or intronless) gene structures, which confer evolutionary advantages promoting subtype divergence and expansion through gene copying or duplication. (nature.com)
Variant1
One sample was positive, and subsequent sequencing and phylogenetic analysis showed that this virus represented a new HEV variant. (cdc.gov)
Evolution1
Amphibians, therefore, may serve as overlooked vectors/hosts for zoonotic pathogens and the amphibian IFN system provides a model to study IFN evolution in molecular and functional diversity in coping with dramatic environmental changes during terrestrial adaption. (nature.com)
Samples1
To screen more samples for this new virus, we developed a specific real-time reverse transcription PCR (RT-PCR) ( Technical Appendix ). (cdc.gov)
Year1
In subtropical and tropical regions, seasonal influenza epidemics follow a similar pattern, but influenza illnesses can occur throughout the year. (cdc.gov)