Where Do Flu Viruses Come From?

Where does the flu originate from?

Answer: Influenza is a virus that’s spread from person to person.

It originates, actually, among birds and other animals such as pigs, and new viral strains of influenza come to this country and to Europe from Southeast Asia.

That’s the global pattern..

Why is the flu worse in winter?

The virus lives longer indoors in winter, because the air is less humid than outside. While it’s alive and in the air, it’s easy for people to inhale it, or for it to land on the eyes, nose, or mouth. We spend more time indoors and have closer contact with each other, which makes it easier for the virus to spread.

How does the flu infect a human host?

When the influenza virus infects a host cell its goal is to produce many copies of itself that go on to attack even more cells. A viral enzyme, called polymerase, is key to this process. It both copies the genetic material of the virus and steers the host cell machinery towards the synthesis of viral proteins.

Why does flu season end?

Why flu season is in the fall and winter “The virus survives better in cool, dry temperatures,” Simanek said. And that’s thanks to a protective gel-like coating that surrounds the flu virus while it’s in the air. The flu is an airborne infectious disease.

How do viruses make you sick?

Viruses make us sick by killing cells or disrupting cell function. Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system’s antibodies and other cells to target the invader.

How does the flu virus multiply?

The influenza virus enters the host cell by having its hemagglutinin bind to the sialic acid found on glycoproteins or glycolipid receptors of the host. The cell then endocytoses the virus. In the acidic environment of the endosomes, the virus changes shape and fuses its envelope with the endosomal membrane.

Why does the flu come back every year?

These viruses spread seasonally each year because of a phenomenon known as antigenic drift: They evolve just enough to evade human immune systems, but not enough to develop into completely new versions of the virus. The H3N2 subtype causes the most disease each year.

Where do flu viruses replicate?

Influenza viruses replicate within the nucleus of the host cell. This uncommon RNA virus trait provides influenza with the advantage of access to the nuclear machinery during replication.

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 …

Is Flu A or B worse?

Which is worse: influenza A or influenza B? Influenza type A and type B are similar, but type A is overall more prevalent, sometimes more severe, and can cause flu epidemics and pandemics.

What are the two biomolecules that are found in all viruses?

All viruses contain the following two components: 1) a nucleic acid genome and 2) a protein capsid that covers the genome. Together this is called the nucleocapsid. In addition, many animal viruses contain a 3) lipid envelope. The entire intact virus is called the virion.

What type of virus is the flu?

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.

At what temperature does flu virus die?

By contrast, influenza viruses, which infect the whole body, grow best at temperatures slightly below body temperature, and at 40° C they will die off after 12-24 hours.

How did the 1918 flu start?

Some medical historians and epidemiologists have theorized that the 1918 pandemic began in Asia, citing a lethal outbreak of pulmonary disease in China as the forerunner of the pandemic. Others have speculated the virus was spread by Chinese or Vietnamese laborers either crossing the United States or working in France.

Is the flu a bacteria or a virus?

The flu is a viral infection caused by the influenza virus, a respiratory virus. The common cold is also a viral infection caused by the adenovirus or coronavirus and there are many, many subsets with a lot of variability. That’s why it’s said there’s no cure for the common cold [and] there’s no real vaccine.