- Is influenza A human virus?
- How long is the flu contagious?
- What cells does the flu virus attack?
- How many type A flu viruses are there?
- Is h5n1 influenza A?
- What flu strains are in the 2020 vaccine?
- What are the unique characteristics of influenza virus?
- What does the influenza A virus look like?
- What are the two major types of influenza viruses?
- What disease does influenza cause?
- Whats the difference between Flu A and Flu B?
- Is influenza type A bird flu?
- What type of DNA does the influenza A virus have?
- What is worse Influenza A or B?
- Where do viruses go after flu season?
Is influenza A human virus?
What is type A influenza.
Influenza — also known as the flu — is a contagious viral infection that attacks your respiratory system.
Influenza viruses that infect humans can be classified into three main groups: A, B, and C.
Type A influenza infection can be serious and cause widespread outbreaks and disease..
How long is the flu contagious?
When Flu Spreads Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Children and some people with weakened immune systems may pass the virus for longer than 7 days.
What cells does the flu virus attack?
The main targets of the influenza virus are the columnar epithelial cells of the respiratory tract. These cells may be susceptible to infection if the viral receptor is present and functional.
How many type A flu viruses are there?
There are two main types of influenza (flu) virus: Types A and B. The influenza A and B viruses that routinely spread in people (human influenza viruses) are responsible for seasonal flu epidemics each year. Influenza A viruses can be broken down into sub-types depending on the genes that make up the surface proteins.
Is h5n1 influenza A?
H5N1 is a type of influenza virus that causes a highly infectious, severe respiratory disease in birds called avian influenza (or “bird flu”). Human cases of H5N1 avian influenza occur occasionally, but it is difficult to transmit the infection from person to person.
What flu strains are in the 2020 vaccine?
The committee recommended that the quadrivalent formulation of egg-based influenza vaccines for the U.S. 2020-2021 influenza season contain the following:an A/Guangdong-Maonan/SWL1536/2019 (H1N1) pdm09-like virus;an A/HongKong/2671/2019 (H3N2)-like virus;a B/Washington/02/2019- like virus (B/Victoria lineage);More items…•
What are the unique characteristics of influenza virus?
A clinical characteristic of human influenza is a sudden rise in body temperature to >38.5 °C 1–3 days following infection. Other symptoms include headache, limb ache, tiredness, general faintness and dry cough.
What does the influenza A virus look like?
The structure of the influenza virus (see Figure 1) is somewhat variable, but the virion particles are usually spherical or ovoid in shape and 80 to 120 nanometers in diameter. Sometimes filamentous forms of the virus occur as well, and are more common among some influenza strains than others.
What are the two major types of influenza viruses?
Influenza B and C viruses mainly affect humans, whereas influenza A viruses infect a range of mammalian and avian species. Only type A and B cause human disease of any concern. Influenza virus is transmitted primarily by droplets or respiratory secretions of infected persons.
What disease does influenza cause?
What is Influenza (Flu)? Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs. It can cause mild to severe illness, and at times can lead to death. The best way to prevent flu is by getting a flu vaccine each year.
Whats the difference between Flu A and Flu B?
Unlike type A flu viruses, type B flu is found only in humans. Type B flu may cause a less severe reaction than type A flu virus, but occasionally, type B flu can still be extremely harmful. Influenza type B viruses are not classified by subtype and do not cause pandemics.
Is influenza type A bird flu?
Avian influenza refers to the disease caused by infection with avian (bird) influenza (flu) Type A viruses. These viruses occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species. Avian flu viruses do not normally infect humans.
What type of DNA does the influenza A virus have?
The genome of influenza A viruses consists of eight single-stranded RNA segments, and the viral particle has two major glycoproteins on its surface: hemagglutinin and neuraminidase.
What is worse Influenza A or B?
In the past, it was thought that infection with influenza A was more severe than infection with influenza B. However, a 2015 study in adults with influenza A and influenza B found they both resulted in similar rates of illness and death.
Where do viruses go after flu season?
The influenza A virus does not lie dormant during summer but migrates globally and mixes with other viral strains before returning to the Northern Hemisphere as a genetically different virus, according to biologists who say the finding settles a key debate on what the virus does during the summer off season when it is …