Influenza A Virus: A Case Study

According to Center for Disease Control (CDC), influenza viruses are divided into three types, designated as A, B, and C. Influenza type C usually only causes either very mild symptoms or no symptoms at all. Types A and B, however, are responsible for epidemics of respiratory illnesses that can result in hospitalization, or even death. Influenza is constantly changing over time by mutations. This continual change allows the virus to evade the antibodies that were meant to kill it. A host infected with influenza virus develops antibodies against that virus; as the virus changes, the "first" antibody no longer recognizes the "newer" virus and infection can occur because the host does not recognize the new flu virus as a problem until the infection is well under way. The first antibody developed may, in some instances, provide partial protection against infection with a new influenza virus. According to Medicine Net.com, In 2009, almost all individuals had no antibodies that could recognize the novel H1N1 virus immediately. It quickly spread throughout the world so fast that the WHO declared this new flu strain (termed novel H1N1 influenza A swine flu). There are currently four main strains of influenza circulating worldwide. Three of the viruses are type A, and one is type B. Type A viruses are divided into subtypes based on the differences in two viral proteins called hemagglutinin (H) and neuraminidase (N). The three subtypes of influenza A are A(H1N1), A(H3N2), and A(H5N1). The reason for several strands of type A are because of the two kinds of change influenza A

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:

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.

According to the CDC there was a breakout in “1918-19 Flu pandemic, which killed as many as 50 million people worldwide”causing the biggest breakout for Influenza (Reconstruction of 1918 Influenza Pandemic Virus). Influenza originated from Asia and the Middle East. Virtually all mammalian species have influenza. Influenza is a contagious respiratory illness caused by the Influenza virus. There are three types of Influenza: type A, type B, and type C. Influenza has numerous symptoms, vaccinations, and is unlikely to kill it’s host.

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.

Influenza A virus is extremely virulent and is known for being the most severe type of influenza. This type of virus generally resides in aquatic birds, which act as hosts for the virus. However, influenza A is capable of being transmitted to other species which

Like inter-subtype reassortment, however, intra-subtype reassortment plays a crucial role in increasing viral genetic diversity and adaptation plasticity [16-20]. The importance and the impact of influenza intra-subtype reassortment extends to all aspects of the influenza virus, from its evolution to its spread, disease severity, and vaccine efficacy. For instance, reassortment events within influenza H1N1 subtype triggered the emergence of unusually severe seasonal epidemics of 1947 and 1951, and reassortment within the seasonal H3N2 influenza led to the dramatic rise and world-wide spread of resistance to adamantine drugs [21, 22]. In 2003, reassortment between two antigenically distinct lineages of H3N2 caused a major change in viral antigenic properties, leading to poor vaccine match and reduced vaccine effectiveness [23, 24]. Intra-subtype reassortment of H3N2 has also been shown to temporarily increase the rate of adaptive amino acid replacements within the reassorted variants, and to be the major determinant of this virus’ evolution, superseding the contribution of adaptive processes [17, 18, 20, 23, 25,

The influenza virus usually has a round shape; it can be elongated or even have an irregular shape at times. In addition, it has a layer of spikes on its exterior. Note that there are two different types of these spikes. Each spike has its own protein, one is the hemagglutinin (HA) protein and the other is the neuraminidase (NA) protein. The HA protein lets the virus to attach to a cell, so it can enter into a host cell and start the infection process (every virus must enter cells in order to make more copies of themselves). The NA protein is needed for the virus to leave the host cell, so that new viruses that were made inside the host cell can infect more cells. Because these proteins are present on the surface of the virus, they are visible to the human immune system. Inside the layer of spikes, are eight pieces of RNA that contain the genetic information for making new copies of the virus. Each segment contains instructions to make one or more proteins of the virus.

According to Healthy People 2020 a goal of theirs is to “increase immunization rates and reduce preventable infections.” The influenza virus is one of these preventable infections, which can cause serious harm to patients. The influenza virus is known as the “flu.” Everyone in his or her life has had some experience with the flu, whether that is himself or herself or a family member. What if there was a way to ensure people from contracting a strain of the influenza virus? Well, thanks to technology and medical research there is.

Influenza A viruses, which have been isolated from a wide variety of avian and mammalian species, including pigs, horses, mink, wild birds and humans are the common pathogens with high variability that cause acute respiratory disease (Lin et al., 2007). They are responsible for both seasonal influenza outbreaks and occasional pandemics affecting millions of people worldwide. Besides, they are divided into two groups, highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI). Mortality of HPAI may be as high as 100% whereas LPAI causing milder symptoms (Metreveli, 2006). Furthermore, they are classified into subtypes based on the antigenic differences of the surface glycoproteins, hemagglutinin (HA) and neuraminidase

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

Restate Thesis: Influenza is a common virus that is present in almost every part of the world. Studies show that influenza causes people to be prevalent to other diseases, especially respiratory diseases. According to an article on The Lancet, August 14th, 2009 by Jamieson, the virus caused the widespread outbreak of respiratory infection

As already mentioned, the H5.N1 is a subtype of an influenza A type. This type consists of RNA. This RNA names as HA and NA. The HA is glycoproteins found on the surface of the virus. This special protein helps the virus to bind to the host cell. While NA is glycosylated enzyme sits on the surface as well. It helps to release the virus from the host cell. In reality, the least pathogenic virus is H5.N1 or (LPAI H5N1), is commonly happening in wild birds for example, in 1983 it is reported that the virus being carried by the ring-billed gulls in Pennsylvania, ( Bird flu (H5.N1) Genetic in news-medical). The virus itself cannot be pathogenic unless some changes occur, which means new progeny. When the RNA of two viruses enters a combination process in the host cell.