Introduction
The influenza virus is an RNA virus has an envelope that included members of the family Orthomyxoviridae. Its genome is a single negative strand segmented RNA. This virus consists of three types: A, B, and C. Influenza types A and B has eight segments of RNA, but the influenza virus type C only has 7 segments (Cheung and Poon, 2007). Influenza A virus is a virus that spread and infect many species of animals such as pigs, horses, cats, tigers, leopards, marine mammals and fowl and including humans. Type A viruses are divided into several subtypes were composed out of two (2) types of glycoproteins on the surface. These proteins are called hemagglutinin (HA) and Neuraminidase (NA) (Cheung and Poon, 2007).
Avian Influenza (AI) is
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Based on the level of AI virus infection can be grouped into two levels of infection that is highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI). Pathogenicity AI virus is determined by the amino acid sequence at the cleavage site region glycoprotein hemagglutinin (HA) and the distribution of host cell protease (Suzuki, 2009). Each HA monomer initially a single polypeptide precursor (HA0) and then cut into two subunits namely HA1 and HA2. HA gene proteolytic cleavage site in the region is indispensable for virus infectivity. HA cleavage site area depends on the presence of basic amino acids (arginine: R) (Suguitan et al., 2011). In most of the AI virus non-virulent or have low pathogenic monobasic amino acids in the cleavage site region (PQKETR * GLF), while the highly pathogenic strain has polybasic cleavage (PQGERRRKKR * GLF). Polybasic cleavage sites that are identical with polybasic cleavage sites HPAI is found in all the clade 2 H5N1 viruses to other Asian, European and African countries (Ducatez et al., 2006; Salzberg et al., …show more content…
Wild aquatic birds are the natural reservoir of influenza virus types A and is vital to the ecology and virus propagation. From this reservoir, influenza virus type A usually can be transmitted to other birds, mammals including humans and can cause outbreaks of severe illness or death. The number of combinations of HA-NA were found in wild birds indicates that mixed infections and AI virus reassortment frequently in wild birds.
On land birds, quail considered an intermediate host for the virus duck. The quail is more vulnerable than in chickens against 14 subtypes of the 15 HA subtypes of AI virus derived from waterfowl, and the pattern of amino acid subtype H9 origin quail is the intermediate host of the AI virus origin of duck and chicken (Yamada et al., 2011). Furthermore, in a study shows that changes in the HA gene of duck origin avian influenza virus for adaptation at Quail allow the AI virus can cause infection between species that infects birds land, such as chicken (Perez et al.,
However due to globalization, import and export viruses is more easily transmitted. Over the past century the global community especially Asian has been affected with new strains of the influenza virus. The changes in the virus can occur in two ways “antigenic drift” which are gradual changes in the virus over time. This change produces new strains that the antibody may not recognize. “Antigenic shift” On the other is a sudden change in the influenza virus which ‘’ results in a new influenza A subtype or a virus with a hemagglutinin or a hemagglutinin and neuraminidase combination that has emerged from an animal population,” as seen with H5N1 virus. This change leaves people defenseless against this new virus. (CDC, 2013) Currently there is no vaccine to combat all strains therefore “Planning and preparedness for implementing mitigation strategies during a pandemic requires participation by all levels o...
"MIT Finds Key To Avian Flu In Humans." Space Daily 7 Jan. 2008. General OneFile. Web. 18
The Avian Flu Virus in Chicken There are only ten more days until we celebrate our biggest holiday of the year, Chinese New Year. It is the year of the monkey, the monkey in our culture is supposed to be very lively and mischievous and full of energy. It has been three months since I had chicken, I have been eating fish and vegetables, but I really miss eating chicken meat. In our village where there are 20 families, 14 families are in the business of selling poultry to support their income, many of them also sell eggs to supplement their income.
The influenza virus is most commonly spread from person to person by coughing or sneezing. The virus can also be spread by touching an object that was recently contaminated. Then accidently touching their mouth or
Over the past fifteen years H5N1 influenza (also known as Avian Flu or Bird Flu) has become a common topic of speculation and debate worldwide, causing quite a bit of confusion about its possible impacts on our society. At this point in time it is generally recognized by the international medical community that Avian Flu is bound to become a pandemic, most likely within the next ten years. Research on Avian Flu and its effects have led many scholars to make grave predictions of major global turmoil while a small portion of medical scientists remain skeptical, believing we will have enough time to thoroughly prepare for the outbreak. The one thing that nearly all health professionals seem to agree upon is that the avian flu will surely have a large impact on the development of humankind. To truly understand the threat of this disease and what we must do to prepare for it, we need to look at the issue from multiple angles and consider what the spread of a disease so lethal and so prone to mutation would mean for our daily lives, health professionals, laws and government procedures, and of course the continuation of the human race.
The influenza virus is an enveloped virus that contains a genome of eight genes that define what the virus is. Everything begins when the virus enters the airways. Here, influenza viruses specifically attach to the surface of epithelial cells. The viral membrane envelope contains the neuraminidase (NA) protein, which is important for the efficient release of newly produced viruses. It also contains the matrix 2 (M2) ion channel that promotes viral structural changes during cellular entry as well as the influenza hemagglutinin (HA) protein, the key player for viral internalization, which facilitates viral binding to sialic acid decorated receptors on host cells, causing adsorption to the host cell (Samji, p. 3). Barry compares the HA proteins to little spikes and the NA proteins to tiny trees that both protrude all around the surface of the virus (p. 103). When the HA protein spikes come into contact with the sialic acid molecules, both structures bind to one another. Once this binding holds the virus and host cell together, the virus has achieved its first task of adsorption. Next, the virus particles are internalized into endosomes by clathrin mediated endocytosis. The pH of the endosomes drops tr...
Influenza is a major public health problem which has outbreaks all over the world. Resulting in considerable sickness and death rates. Furthermore, it is a highly infectious airborne disease and is caused by the influenza virus. Influenza is transmitted easily from one person to another person, which has a great impact on society. When a member of society becomes sick, it is more prone to spread to other people.
The influenza pandemic of 1918-1919 killed more people than the Great War, known today as World War I (WWI), at somewhere between twenty and forty million people. (1) Influenza is a virus that appeared in 1918 and caused a pandemic. It made an enormous impact that is still significant to the world today. It has pushed scientists to make advancements in the medicine and vaccination industry that continue to grow each and every day. Influenza may be a horrible thing, but without it we wouldn’t be where we are today.
Reid, A. (1999). Origin and evolution of the 1918 Spanish influenza virus hemagglutinin gene. Proc. Natl. Acad. Sci. USA, 96, 1651-1656.
“Selecting the Viruses in the Seasonal Influenza (Flu) Vaccine.” Centers for Disease Control and Prevention. USA.gov, 9 March 2011. Web. 19 Jan. 2010
Influenza or flu is caused by RNA viruses of the family orthomyxoviridae, that affects the nose, throat, and lungs- the respiratory system. The common symptoms are: fever and respiratory problems, such as cough, sore throat,stuffy nose, as well as headaches and muscle aches. Influenza viruses are spread mainly by droplets made from people coughing, sneezing or talking while having the flu. These droplets can land in the mouths or noses of people or can inhaled into the lungs. It is least common for the virus to spread by touching an infected surface then their mouth or nose. Flu viruses are divided into 3 categories, A, B, C. A and B are responsible for problems in the respiratory system that typically occurs during the winter. Influenza types C is quite different from A and B. Type C only cause mild respiratory symptom or none at all.
The swine influenza or swine flu is a respiratory disease in pigs that is caused by the type A influenza viruses. These viruses are referred to as swine flu viruses but scientifically the main virus is called the swine triple reassortant (tr) H1N1 influenza virus. When the viruses infect humans they are called variant viruses. This infection has been caused in humans mainly by the H1N1v virus in the United States. The H1N1 virus originates in animals due to improper conditions and the food they ingest. The virus stays in latency form, thus harmless to the respective animal. The longer the animals survive the more likely the virus is to develop and strengthen making it immune to vaccines. The virus reproduced through the lytic cycle. The virus injects its own nucleic acids into a host cell and then they form a circle in the center of the cell. Rather than copying its own nucleic acids, the cell will copy the viral acids. The copies of viral acids then organize themselves as viruses inside of the cell. The membrane will eventually split leaving the viruses free to infect other cells.
Recent concerns regarding the risks of Avian flu and other exotic diseases prompted some local poultry farmers to adopt strict biosecurity protocols in order to keep their birds safe. ...
(39) World Bank. Projects - Haiti: AVIAN INFLUENZA CONTROL AND HUMAN INFLUENZA EMERGENCY PREPARDNESS AND CONTROL. 2010; Available at: http://web.worldbank.org/external/projects/main?pagePK=64283627&piPK=73230&theSitePK=40941&menuPK=228424&Projectid=P111667. Accessed 6/27/2010, 2010.
Thorlund K, Awad T, Boivin G, Thabane L. Systematic review of influenza resistance to the