influenza type A virus
Quick Summary
Influenza A is a type of virus that causes acute respiratory tract infections, leading to seasonal epidemics and occasional pandemics. It belongs to the Orthomyxoviridae family and is distinguished by surface antigens called hemagglutinin (H) and neuraminidase (N). The H1N1 subtype is well-known for causing widespread outbreaks, including the devastating 1918-19 pandemic.
Influenza A viruses evolve through antigenic drift (minor mutations) and antigenic shift (major genetic reassortment, often involving animals like pigs and birds). This constant evolution allows the virus to evade the human immune system, making it a persistent global health concern. While seasonal flu primarily affects the young and elderly, some strains can cause severe illness across all age groups. Antiviral drugs like oseltamivir and zanamivir, along with annual vaccination, are key strategies for prevention and treatment.
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- bird fluSubtypes of bird flu virus
…any of several subtypes of type A influenza virus, which is classified as an orthomyxovirus. Other subtypes of this virus are responsible for most cases of human influenza and for the great influenza pandemics of the past (see influenza pandemic of 1918–19 and influenza pandemic (H1N1) of 2009). Genetic analysis…
Read More…any of several subtypes of type A influenza virus, which is classified as an orthomyxovirus. Other subtypes of this virus are responsible for most cases of human influenza and for the great influenza pandemics of the past (see influenza pandemic of 1918–19 and influenza pandemic (H1N1) of 2009). Genetic analysis…
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influenzaPandemics and epidemicsInfluenza type A virus is the most frequent cause of seasonal influenza. When an influenza A virus undergoes an antigenic shift, a pandemic affecting most of the world can occur within a matter of months. The influenza pandemic of 1918–19, the most destructive influenza outbreak…
Read MoreInfluenza type A virus is the most frequent cause of seasonal influenza. When an influenza A virus undergoes an antigenic shift, a pandemic affecting most of the world can occur within a matter of months. The influenza pandemic of 1918–19, the most destructive influenza outbreak…
Read More- influenzaClassification of influenza viruses
The A viruses cause the great influenza epidemics, and the B viruses cause smaller localized outbreaks. The C viruses cause only mild respiratory illness in humans. Influenza D viruses are not known to infect humans and have been observed only in pigs and cattle.
Read MoreThe A viruses cause the great influenza epidemics, and the B viruses cause smaller localized outbreaks. The C viruses cause only mild respiratory illness in humans. Influenza D viruses are not known to infect humans and have been observed only in pigs and cattle.
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antiviral drugAnti-influenza drugs…two groups of RNA-containing viruses, influenza A and influenza B. When the RNA is released into the cell, it is directly replicated and also is used to make protein to form new viral particles. Amantadine and rimantadine are oral drugs that can be used for the prevention and treatment of…
Read More…two groups of RNA-containing viruses, influenza A and influenza B. When the RNA is released into the cell, it is directly replicated and also is used to make protein to form new viral particles. Amantadine and rimantadine are oral drugs that can be used for the prevention and treatment of…
Read More- oseltamivir
…is active against both influenza type A and influenza type B viruses. Oseltamivir and a similar agent called zanamivir (marketed as Relenza) were approved in 1999 by the U.S. Food and Drug Administration and represented the first members in a new class of antiviral drugs known as neuraminidase inhibitors. Oseltamivir…
Read More…is active against both influenza type A and influenza type B viruses. Oseltamivir and a similar agent called zanamivir (marketed as Relenza) were approved in 1999 by the U.S. Food and Drug Administration and represented the first members in a new class of antiviral drugs known as neuraminidase inhibitors. Oseltamivir…
Read More - rimantadine
…to treat infections caused by influenza type A virus, the most common cause of influenza epidemics. Rimantadine is a derivative of the antiviral agent amantadine. It is composed of an alicyclic compound called adamantane that contains a methyl group (CH3) attached to an amine. This arrangement distinguishes
Read More…to treat infections caused by influenza type A virus, the most common cause of influenza epidemics. Rimantadine is a derivative of the antiviral agent amantadine. It is composed of an alicyclic compound called adamantane that contains a methyl group (CH3) attached to an amine. This arrangement distinguishes
Read More - zanamivir
…is active against both influenza type A and influenza type B viruses. Zanamivir and a similar agent called oseltamivir (marketed as Tamiflu) were approved in 1999 by the U.S. Food and Drug Administration and represented the first members in a new class of antiviral drugs known as neuraminidase inhibitors. Zanamivir…
Read More…is active against both influenza type A and influenza type B viruses. Zanamivir and a similar agent called oseltamivir (marketed as Tamiflu) were approved in 1999 by the U.S. Food and Drug Administration and represented the first members in a new class of antiviral drugs known as neuraminidase inhibitors. Zanamivir…
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