How influenza replicates in the human body Influenza, commonly called the fu, is a viral infection that attacks the respiratory system. 5 to 20 percent of Americans will be infected by the flu virus every year, causing about 200,000 hospitalizations and 36,000 deaths (Colds/Flu, National center for complementary and integrative health, nccih.nih.gov). The influenza virus enters the cell, injects its nucleic acid, transcribes the RNA, assembles the new virion, and begins lysis of the cell. Influenza begins its cycle by entering the host cell. Influenza has specifically evolved to enter a cell without alerting any immune system cells. To enter the cell, the virus will make use of attachment proteins. Attachment proteins are vital for …show more content…
This acidic environment will enable the virus to open its matrix 2 ion channels. Once the ion channels are opened, the newfound acidity will trigger the release of vRNP into the host cell's cytoplasm. The viral capsid acts as the barrier between the world and the most important part of the virus, the nucleic acid. The viral capsid is composed of matrix protein M1 (Virus Structure, fsu.edu) that holds everything together and plays a role in virus assembly. The viral capsid is the backbone of the virus that holds everything together and has three main functions: to protect the nucleic acid from digestion by enzymes, to hold the attachment proteins needed to enter cells, and it provides special sites on the surface that allow the virus to attach to cells. Inside the viral capsid is the RNA (ribonucleic acid), this acid is the set of instructions that code for every single action the virus takes. RNA is made of: cytosine, adenine, guanine, and uracil. Each of these are nucleotides that pair up with other specific nucleotides to do a certain job, e.g. cytosine goes with guanine while adenine goes with uracil (complementary base pairing, wisc.edu). RNA has eight segments that code for proteins, some of the proteins that the influenza A virus codes for are: PB1, PB2, PB1-F2, PA, HA, NP, NA, MI,
When we hear the word virus, we usually think of something that makes us sick. A virus is an ultramicroscopic infectious organism that, having no independent metabolic activity, can replicate only within a cell of another host organism. A virus consists of a core of nucleic acid, either RNA or DNA, surrounded by a coating of antigenic protein and sometimes a lipid layer surrounds it as well. The viral genome provides the genetic code for replication, and the host cell provides the necessary energy and raw materials. To fight viruses, we use vaccines. While some may infect a broad range, other viruses can only infect certain kinds of cells. Vaccines are made of inactive, dead or weakened virus cells or protein antigens that can no longer infect
Influenza is an infectious illness that can be spread from one individual to the next. It can be transmitted by means of saliva, nasal secretions, feces and blood. It can also be spread by coming in contact with the virus on contaminated surfaces. Influenza is responsible for an average of 36,000 deaths and for more than 226,000 hospitalizations each year in the United States. (Davidson, 2007-2009, Davis, 2007).
Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell. In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more stealthy and protected. There are two cycles in which a virus can go into: lytic and lysogenic. The lytic cycle consists of the virus attaching to a cell, injecting its DNA, and creating more viruses, which proceed to destroy the host. On the other hand, the lysogenic cycle includes the virus attaching to the cell, injecting its DNA, which combines with the cell’s DNA in order for it to become provirus. Then, the provirus DNA may eventually switch to the lytic cycle and destroy the host.
They view proteins created by infected cells, and are sent to other cells to start them making protective substances. Influenza, commonly known as the flu, is a very contagious disease caused by a virus infecting many part of our bodies including the reparatory tract. The influenza virus depending on the sternness usually includes: fever, cough, sore throat, headache, stuffy and running nose, muscle soreness and fatigue. It also can include vomiting, diarrhea, and nausea.
First of all, the name “Influenza” is derived from the Latin word for “influence”, and it is an infectious disease that is caused by the RNA viruses from the Orthomyxoviridae family:
The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell.
Influenza viruses need to infect host cells in order to replicate. Most flu viruses are destroyed by the innate immune mechanisms involving components such as macrophages, interferons and natural killer cells, however some manage to avoid being detected by these early defence mechanisms and so are eliminated by the adaptive immune response.
One can claim that influenza is an infection that has victimized people from just about every generation that we have known. The term Influenza comes from the Latin word "influentia", first used by the Italians in the 1600's. It is a highly contagious infection particulary of the respiratory tract.In addition to us humans, influenza can occur in pigs, horses, and several other mammals as well as in certain wild and birds. It can also jump from specie to specie as observed in late 1997 when influenza from chickens was having its effects on people in Hong Kong. Because influenza is highly contagious and spreads easily, it has appeared in our history many a times as epidemics. Influenza is caused by an
The influenza virus is “an acute respiratory tract illness, with outbreaks occuring annually that are responsible for large numbers of hospitalization and death worldwide” (Dool et al. 314-319). The influenza virus has a few common symptoms that
There are there types of influenza A and C or the most severe types and B which is the most common, Luckily not the to severe. The virus works by first attaching to the outside of a host cell. It injects its RNA into the cell. Unfortunately our cells treat the RNA like they should. It translates the viral genes using the cell’s ribosomes and enzymes. Now the virus can take the cell over and use it to reproduce more viruses. Sooner or later it releases the new nauseating viruses and they search for another cell to raid.
In the first place, influenza is caused by influenza virus (Infectious Diseases). According to Mortada, there are three types of viruses, A, B, and C and the virus
Influenza, or more generally recognized as the flu, is a virus that affects the upper respiratory system and can infect both humans and animals, but generally circulated throughout humans. It is an eminently contagious illness that is continually changing and has three known strains, Influenza A, B and C. While C causes nothing other than a few minor symptoms, its counterparts B and A can be disrupting, uncomfortable and in serious cases, lethal. Influenza A and B can both cause epidemics and pandemics, as well as being dispersed around seasonally. Symptoms of influenza include chills, a sore throat and cough, runny nose, headache and fatigue. This is because the virus infects your lungs and throat, irritating them. Due to the extra white blood
Influenza is one of the most contagious illnesses caused by airborne viruses. I can lead to mild or severe illness and even death. Influenza can come suddenly and is marginally different to a ‘Cold”. The virus can cause infections of the lower respiratory tract (lungs) and the upper respiratory tract (throat, nasal). Influenza is disease that may cause symptom such as the following; fever (high body temperature), sore throat, muscle or body aches, cough, Headaches, runny or stuffy nose, fatigue/tiredness (CDC, 2016). it belongs to “Orthomyxoviridae” family of infections, “myxa” meaning ‘mucus’ in Greek. There are three major types of influenza that may also be addressed as different terminologies, such as flu
The protective capsid helps the virus escape detection and destruction during the invasion of the host. When the virus reaches the target cell, biochemical reactions between the capsid and cell wall allow the virus to latch on and inject its genome into the cell’s interior. Once inside, the viral genetic material insinuates itself into the host’s DNA or RNA. In an efficient feat of natural bioengineering, the host cell’s genetic machinery now does the rest of the work for the virus. The cell, which had already been making copies of its own genome, now also replicates that of the virus. Coded within the viral material is the blueprint for making more copies of the viral genome. Further instructions command the production of capsids and directions for assembly of new viruses. After the host cell becomes engorged with viruses, it explodes, sending the new
With a huge number of victims, 80 to 100 million, since 1918, the influenza is considered as one of the most pandemic diseases ever. There are three types of influenza virus: influenza virus A, influenza virus B, and influenza virus c. These are a subtypes of the virus family orthomyx-oviride. The types B and C do not cause pandemic diseases while type A does. The type A classified into three main subtype H1.N1, H1.N2, and H3.N2. The (H.N) refers to the two kinds of proteins on the surface of the virus (hemagglutinin and neuraminidase). The difference in numbers is due to the difference in protein variability. A H1.N1 virus which is widely known as Spanish flu is the only type that can transmit from human to human. The H5.N1, or “bird flu”