Avian Influenza Virus Essay

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

That differentiation occurs from time to time at irregular intermissions, which is responsible for widespread outbreaks and makes periodic reformulation of the influenza vaccine necessary. The disease is mainly extented through droplets in crowded and enclosed spaces. The infection may also be spread from person to person by direct contact with the secretions of infected persons. The incubation period is short, usually around 1 to 4

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

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

Influenza type A viruses are divided into subtypes based on two proteins on the surface of the virus. These proteins are called hemagglutinin (HA) and neuraminidase (NA). There are 15 different HA subtypes and 9 different NA subtypes. There are three prominent subtypes of influenza A that are known to infect both birds and people. The first one is influenza A H5; there are nine known subtypes of H5 viruses (H5N1, H5N2, H5N3, H5N4, H5N5, H5N6, H5N7, H5N8, and H5N9). Most H5 viruses identified worldwide in wild birds and poultry are low pathogenic viruses, but occasionally highly pathogenic viruses have been detected. Sporadic H5 virus infection of humans, such as with Asian-origin highly pathogenic avian influenza A (H5N1) viruses currently circulating among poultry in Asia and the Middle East have been reported in 16 countries, often resulting in severe pneumonia with approximately 60% mortality worldwide. The second one is influenza A H7; there are nine known subtypes of H7 viruses (H7N1, H7N2, H7N3, H7N4, H7N5, H7N6, H7N7, H7N8, and H7N9). Most H7 viruses identified worldwide in wild birds and poultry are LPAI

In the article “Avian Influenza: An Agricultural Perspective,” Andrea Morgan (2006) researched the impact avian influenza has on different parts of the world. In her research she realized that the most harmful pandemic of the disease was the “Spanish influenza” which affected 50 million people worldwide. The strain of avian influenza Morgan based her research around was the H5N1 influenza A, which is found in poultry. She researched how fast the influenza can be transmitted and who it affected worldwide. In order to prevent the spread of influenza in the United States, the United States Department of Agriculture (USDA) follows specific measures to ensure that they do not contain the outbreak (Morgan, p. 139). Influenza is most commonly found in birds, but it can also be transmitted to swine causing it to be more easily developed in humans. Which leads to research done by Piaggio, Clark, Franklin, and

The flu (influenza) is a highly contagious virus that attacks the respiratory system. The flu has three strains, H1N1 strain, H3N2 strain and influenza B strain. The first known case according to UXL Encyclopedia of Diseases and Disorders “The first influenza pandemic that is known to have been global in scale took place in 1850; it started in China and spread across central Asia to Africa and then to Europe where it nearly wiped out the populations of several major cities in southern Italy and Spain”. The number of cases in the U.S. and worldwide is according to www.cdc.gov “There has been 11,965 laboratory-confirmed flu-related hospitalizations.” The number of cases in the US and world wide per year is 3-5 million.

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

Influenza is one of the most important human respiratory infections and its seasonal recurrence is a major contributor to human morbidity and mortality. Seasonal influenza has an estimated annual attack rate of 10-20%, leading to 3-5 million cases of severe illness and 250,000 to 500,000 deaths each year [1]. Throughout history, influenza A has also been the greatest contributor of human pandemics. During the last century, four influenza A pandemics (1918, 1957, 1968 and 2009) caused over 50 million deaths globally, created significant social and economic impact on the human society, and shaped future research and public health policies.

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).

Wild birds are considered the reservoir of the type A influenza virus and antigenic shifts caused by mutations are present in many animal reservoir. Antigenic shifts are dangerous because it can be unaffected by the host’s immune system. Pigs can be infected by both human and animal influenza virus, which may lead to recombination and creation of new strains that can be transmitted. Influenza virus can be transmitted from animal to human in cases such as the bird flu (H5N1) or swine flu (H1N1), which experienced an outbreak in

Influenza A is a virus also known as type A flu. The virus is capable of infecting animals and human beings. However, it is more common for humans to suffer the ailments associated with this type of flu. This type of virus is generally responsible for a large outbreak of the flu epidemic. More specifically, influenza is a contagious respiratory infection, which is caused by a variety of viruses.

The Influenza virus first came to knowledge in the 18th centre with influenza being derived from the word influence (Collins English Dictionary, 2014). Modern influenza has developed many strains over the last century with the most recent strand being H1N1. (National Institute of Allergy and Infectious diseases, 2011). In relation to New Zealand the worst outbreak of flu was 1918 killing around 8,600 in total. Since the development of modern medicines and higher sanitary conditions in hospitals; the flu has not been a major killer but it is still relevant in society.

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.

Influenza is a virus that is transmitted mainly via airborne process, which is one of the fastest mode of transmission. It is transmitted though airborne due to symptoms such as coughing and sneezing of the host (the infected). The host sneezes and coughs, influenza can easily be transmitted the agent via droplets and small microorganism, therefore entering the uninfected though the respiratory system (mouth and nasal) (WHO, 2016). Another way the virus can lead to pandemic, is due to the fact that the number of human and animals continue to grow and interact. Thus, the pandemic of influenza type A is possible. This mode of transmission is both and; the airborne (respiratory system) and physically (hand contamination). The customarily begins in rural areas (farms) as the virus can be found in hosts such as horses, pigs, chickens and birds. There has been an undetected interchange of the disease among animals and humans in rural environments which then eventually grows to become a global pandemic (Webster, RG & Monto, AS et al 2013, Textbook of influenza). The virus may continue to spread physically due to hand contamination in public; these may include door handles, public transport and other hand held hold objects. The last mode of transmission is genetically, this may then lead to asthma or even death (WHO,