A Research Study On Influenza Viruses

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

Every year, millions of people start talking about the influenza virus and getting their vaccines as the flu season approaches, which starts around the October-November period and reaches its peak between December and March. Therefore, public health officials around the world- and in the U.S in particular- are constantly challenged by properly preparing for the annual influenza dilemma, given that this viruses, and other respiratory viruses, are a serious health threat to the U.S population and the world as a whole. Furthermore, what makes the influenza virus even more challenging to control is that it can mutate rapidly and reassort to form new strains, having the ability to reside in multiple animal hosts. In fact, many scientists and researchers have been doing in-depth intensive research so as to understand the mechanism behind this unique characteristic of the virus, try to find new ways to control it, and explore different areas of protection and vaccination.

Influenza is not a deadly virus and does have a vaccination. One of the three types of influenza, type C, “type C infections cause a mild respiratory illness and are not thought to cause epidemics” (Types of Influenza Viruses). The other two types of influenza viruses type“ A and B viruses cause seasonal epidemics” and happen mostly when winter hits (Types of Influenza

According to the Centers for Disease Control and Prevention (CDC, 2013) national healthcare disparities report for 2010, influenza and pneumonia are ranked within the top ten major causes of death in the United States. The influenza viruses that will be discussed throughout this case study include the human influenza viruses: A and B. These viruses are responsible for seasonal epidemics during the fall and winter around the globe in temperate environments. Historically influenza outbreaks have had a seasonal distribution and characteristic time course although according to the CDC (2017) factors influencing the extent and severity of an outbreak are less clear. Generally, there are two or three different influenza strains typically circulating concurrently in any given

Wild aquatic fowl, ducks in particular, serve as a reservoir for the Influenza virus to transmit into poultry and then to humans. Infected birds shed flu viruses in their saliva, nasal secretions, and feces (CDC, 2004). The current virus seen in Asia is denoted as H5N1 and was first seen in terns in South Africa in 1961 (CDC, 2004). The first human seen infection of the avian H5N1 viruses was in 1997 in Hong Kong in a three- year old boy (Ruben, 2005). The outbreak involved 18 cases and killed 6, one third of the confirmed infected population (Rueben, 2005). In three days 1.5 million birds were killed in order to prevent further spread. A new pandemic is now on the horizon with recent outbreaks in poultry in the eight Asian countries of Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam since 2004 (CDC, 2005). As of July 5, 2005, there have been 108 reported human cases of the H5N1 virus with 54 deaths (CDC, 2004). In wake of a

The influenza virus is transmitted from human to human mainly by droplet, although there are cases of animal to human transmission. The incubation

However, flu is caused by a different set of viruses than common cold viruses. The three main types of viruses often found during the flu season are Influenza A, B and C. Influenza A viruses are the most common; they are the super bug viruses that infects illnesses in both human and animals. It contains larger members than type B and C viruses. Type A influenza is divided into subtypes such as H1N 1 (Swine flu-pig flu), avian influenza (H5N 1 – bird flu) and H3 N2 (most common flu infection). In short, the H (hemagglutinin) and N (neuraminidase) are the two protein substances found on the surface of the viruses (9). Therefore, flu exhibit a distinct set of symptoms that healthcare professionals are able to differentiate from common cold illness. Moreover, like common cold they are assigned an acronym F.A.C.T.S. to pin point flu illnesses in the diagnosis protocol. F stands for fever; it usually runs higher than100 degree Fahrenheit (38 degree Celsius). In children, if the temperature rises over 103 degree Fahrenheit for more than two days, healthcare officials recommend a visit to Emergency Room in order to prevent the meningitis or brain damage. A is for aches; the flu illness is always present with muscle aches all over body. In most cases, it is severe enough to limit an individual from normal activity and bed confinement. C is for chills; shriveling colds that make it unable to warm up. T is for tiredness; it usually ranges from moderate to severe dependence. S is for symptom onset; flu onset is very sudden. It comes down rather quickly, within 3 to 6 hours, in comparison to common colds which gradually develops over period of day(s) (3, 5, 6, 7, 8). The key components distinguish flu from common cold are the sudden onset symptoms, shriveling cold and allover muscle

IAV is a virus classified as part of the orthomyxoviridae and one of the causative agents of influenza or “the flu”. (Edinger, Pohl & Stertz, 2014) Its natural reservoir is primarily wild aquatic fowl where it is mostly nonpathogenic, though zoonotic infections can occur in mammals and domestic fowl. (Klenk, Matrosovich & Stech, 2008) The jump between species often results in the establishment of highly pathogenic variants that can have devastating effects, as was the case of the “Spanish” influenza pandemic of 1918. (Taubenberger, 2006) The infection across special barriers is dependent on changes to the structure of glycoproteins on the viral envelope, particularly haemagglutinin (HA). The different subtypes of HA and neuraminidase (NA) serve to classify different viral lineages. These changes in the structure can result in proteolytic activation; that when coupled to changes of receptor binding specificity allow for interspecies transmission. (Klenk, Matrosovich & Stech, 2008) The modifications can affect the pathogenicity of the virus even within the same species, which can allow for infection of new cell types, or even systemic disease. (Steinhauer, 1999) These mutations accumulate through successive replications or genetic re-assortment during confection. The resulting structural changes account for the observed antigenic drift that causes loss of immunity despite prior exposures to the virus. This evolutionary process drives the consistent

Swine endemic strains are called swine influenza virus (SIV) and all known strains of SIV are classified as Influenza virus A (common) or Influenza virus C (rare). In general, this virus is not common among humans, but some cases of human infection have been reported recently. In humans, the symptoms of swine flu are similar to those of other influenza and influenza-like illnesses. They include fever, cough, pharyngitis, body pain, headache, chill and fatigue. Some cases present with diarrhea and vomiting. Swine Flu is extremely prevalent in pigs and those pigs are the main cause of transmitting this disease to

Influenza (flu) is an acute, contagious and fast-spreading respiratory infection caused by the influenza virus. Virus spread through the contact between persons, contact with contaminated items or the droplets in the air. Typical symptoms are high fever, chills, body aches, significant fatigue and mild respiratory infection. There is a high incidence of infection in autumn and winter, complications and mortality are very serious. This influenza viral disease can be classified into three types, A, B and C which cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high fevers. This disease is self-limiting, but serious complications such as pneumonia in infants, children, elderly

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

A disease that can affect numerous species ranging from humans to birds and even swine is the influenza virus (Kapoor and Dhama 2014). The influenza virus is separated into three genera; A, B, C (Kapoor and Dhama 2014). While all three types of influenza have their own effects on different populations the one that is mostly known for pandemics is influenza virus A (Kapoor and Dhama 2014). This viral strain functions through a different charged sense located in its RNA genome; an area where deleterious mutations can increase in the body of its hosts allowing replication (Webster and Govorkova 2014). The popular subtype that cause the respiratory immune issue is mostly from H1N1; a serious and deathly disease (Kapoor and Dhama 2014). While influenza virus A can cause numerous complications to the human population it is also known for its relationship among humans and mammals (Kapoor and Dhama 2014). The virus circulates among many bird species causing concerns and risks to spread in further populations worldwide (Webster and Govorkova 2014). NEED MORE INTRO

Two distinct lineages of H9N2 influenza viruses exist: North American and Eurasian lineages. The Eurasian lineage is composed of at least three sub-lineages. This lineage is divided into three major sub-lineages represented by their prototype strains: A/chicken/ Korea/38349-p96323/96 (Korean-like), A/duck/Hong Kong/ Y280/97 (Y280-like), and A/quail/Hong Kong/G1/97 (G1-like) [13, 23]. Throughout the second half of the 1990s, outbreaks resulting from H9N2 subtypes were reported in many countries, namely Germany, Italy, Ireland, South Africa, USA, Korea, China, and the Middle Eastern countries such as Saudi Arabia and Iran [4].

The virus was a unique combination of swine, bird, and human influenza viruses and its genetic composition was different from the human seasonal H1N1 viruses that were in circulation among people since

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”