Influenza A H1N1 Virus

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

Throughout the history, influenza viruses have caused several pandemics or global epidemics, killing many people. For example, the influenza strike in 1918 to 1919 infected an estimated 500 million people worldwide, which is one-third of the planet’s population at the time and killed an estimated 20 million to 50 million people. More than 25 percentage of the U.S. population were affected, and caused 675,000 deaths in U.S during the pandemic.(History, 2015). There were no effective treatments for this type of influenza and no available vaccines can prevent its spread during the period. (History, 2015) U.S government required general population to wear masks and other protective equipments in public areas, and many public places also closed due to the influenza strike. Health care providers tried everything they knew to save people, but none shows any evidence of effects. (National Center for Biotechnology Information [NCBI], 2015). Scientists found out that the influenza virus had invaded their lungs and caused pneumonia, which made so many people died from the pandemic (History,2015). Another influenza strike happened

Influenza, an innocent little virus that annually comes and goes, has always been a part of people’s lives. Knowing this, one would not believe that it has caused not one, not two, but three pandemics and is on its way to causing a fourth! The Spanish flu of 1918, the Asian flu of 1957, and the Hong Kong

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.

Avian influenza is a disease that has been wreaking havoc on human populations since the 16th century. With the recent outbreak in 1997 of a new H5N1 avian flu subtype, the world has begun preparing for a pandemic by looking upon its past affects. In the 20th Century, the world witnessed three pandemics in the years of 1918, 1957, and 1968. In 1918 no vaccine, antibiotic, or clear recognition of the disease was known. Killing over 40 million in less than a year, the H1N1 strain ingrained a deep and lasting fear of the virus throughout the world. Though 1957 and 1968 brought on milder pandemics, they still killed an estimated 3 million people and presented a new

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

The virus has been studied in detail during 2009-2010. Being a complex virus, it is important to study the current scenario and the trends of the circulating virus. During 2015, the incidence of pandemic H1N1 2009 influenza virus among patients presenting with ILI, diagnosed in our tertiary care hospital during the study period was 18.6%. In the 2012-2013 the incidence of pandemic H1N1 2009 influenza virus among patients presenting with ILI, was 8.20% indicating a sharp increase in the number of cases. 9 After 2010, the 2009 pandemic H1N1 influenza A reappeared in several northern and western states of the country during the winter months of 2012-2013. The presently ongoing resurgence since December 2014 however appears to be worse than the previous one, leading to over 30,000 cases and 2000 deaths countrywide (as of 28th March,2015) as compared to 5044 cases and 405 deaths in 2012 and 5250 cases and 692 deaths in 2013.10 The resurgent waves lead to more number of hospitalizations and deaths due to pdmH1N1 as compared to the rest part of the year and appear at an interval of 1.5-2

Influenza pandemics are caused by type A virus. Influenza A viruses have two specific antigens Hemagglutinin (HA) and neuraminidase (NA) on their surfaces. Various influenza strains are identified by the combination of their HA and NA antigens. HA protein antigens allow

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

The influenza virus, also known as the seasonal flu, is a viral and contagious disease that was once recognized as one of the most devastating illnesses in global history. From 1918 to 1919, an estimated 500 million people worldwide fell sick with this illness and killed nearly 10%. In the United States, 675,000 Americans died during the pandemic, suffering from fever, body aches, nausea, and other impacting symptoms with little opportunity for treatment. First observed in Europe, flu outbreaks swept through parts of Asia and South America, Africa, and North America. At first, scientists like Robert Koch, believed that the cause of influenza was a bacterium called Haemophilus influenzae, but eventually discovered it was viral. Nonetheless, there were no effective treatments that helped kill the viral strain or prevent its spread. At the time, people were ordered to wear masks, and public entities like schools were closed for an extended period of time. Even today, there are very few methods of remedy other than rest, fluids, and staying warm. One drug that was approved by the FDA in 1999 that treated for influenza in adults was oseltamivir, or Tamiflu. However, it wasn’t put to use until 2005 in Southeast Asia when the H5N1 avian influenza epidemic erupted. Currently, Tamiflu continues to be used as the main drug for treating the flu. A downside to this medication, however is that it must be administered 48 hours within experiencing the first symptoms; otherwise it doesn’t

Structure: The influenza virus looks like a sphere covered with spike like proteins for grip ready to latch on to a healthy human cell. “The H spike (hem agglutinin) and the N spike (neuraminidase) are called proteins and exist in the envelope and they are used for antigenic typing” (Pearson 2004). These proteins allow the virus to enter and exit the host (our cells). Once the virus is inside the cell, the virus can begin reproducing. Soon, each infected cell is filled with thousands of new viruses, each of them looking to leave the cell to find a new home in another cell and begin reproducing there.

Influenza viruses are categorized into 3 different viruses, A, B, and C. The A and B influenza

Unlike DNA viruses, the RNA influenza virus lacks the proofreading mechanism to self-repair arising errors during its replication. Thus two forms of genetic variations representing a hallmark feature of influenza viruses. The antigenic drift occurred in influenza type A and influenza type B. The accumulation of changes in surface glycoproteins, hemagglutinin and neuraminidase, by gene sequence mutations of virus RNA segments causing the antigenic drift. These mutations cause minor changes in HA and NA antibody-binding sites generating novel strains of influenza virus that responsible for the seasonal epidemics. As these novel strains are not detectable by host antibodies that were generated against previous strains, they can infect both vaccinated

Influenza, more commonly known as the ‘flu’, is a chameleon like infectious disease, that presents itself with varying characteristics from year to year, due to the wavering identity of the strain. “Like HIV, influenza is an RNA virus, constantly changing its appearance and adept at eluding recognition by the human immune system” (Schneider, 2014). From its inception of 1918, influenza claims an average of 250,000 to 500,000 people worldwide, annually. Little is known of the virus’s origin however; recent studies examined pathology specimens belonging to deceased soldiers of 1918, revealing similarities with that of the avian flu virus (Schneider, 2014). Evidence has correlated a pattern of influenza strain elements, accompanied by consistent transmutation, that has established a paralleled relationship between that of animal reservoirs and Asia. It is believed that global transmission of the virus is carried via birds that consume food from the same sources that of pigs, consisting of contaminated feed and waterfowl. “Human and animal influenza viruses incubate in a pig’s digestive system, forming new genetic combinations” (Schneider, 2014). Asia occupies cohabitation of the two species that yield fertile breeding grounds for a virus to manifest, while posing a significant threat and concern to the heavily populated areas within close proximity.

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”