Pandemic H1N1 (pan-H1N1) influenza virus was first reported in Mexico during April of 2009 followed by rapid spread to different countries (1). Although the origin of the 2009 pan-H1N1 is unclear, the virus is genetically closely related to triple reassortant (TR) swine influenza viruses (SIVs) currently circulating in swine. Classic H1N1 SIV has been widely reported since an influenza-like outbreak was first detected in swine in the United States (U.S.) during the catastrophic 1918 human influenza pandemic (2). The classic H1N1 SIVs were exclusively prevalent among swine populations in the U.S. before novel TR H3N2 viruses emerged in 1998. Genes of TR H3N2 viruses were derived from human, swine and avian lineage viruses. This specific constellation of internal genes is referred to as the TR internal gene (TRIG) (3). Currently, classical, TR and human-like H1 viruses are circulating in the U.S. swine population (4). Pigs are susceptible to influenza viruses of different origins and they are considered as mixing vessels for genetic reassortment(3), thus co-circulation of different influenza strains including pan-H1N1 viruses in swine increase the potential of novel reassortants emergence (4, 5), and recent reports further highlight the reassortment events between swine and pandH1N1 viruses (6, 7).
Here we report the isolation of novel reassortant H1N2 influenza viruses with genes derived from contemporary swine and the 2009 pandH1N1 viruses. In October and November 2010, oral fluid samples were collected from 5-month-old and 8-week-old nursery pigs, respectively, showing mild respiratory signs of cough and depression. The farms are 30 miles apart with different servicemen. Filtered samples were inoculated into Madin Darby canine k...
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...f both origin. Compared to the pan-H1N1 and all other reported swine/pandH1N1 reassortants, the two U.S. reassortant isolates demonstrated one (E16G) and four (G34A, D53E, I109T, and V313I) unique amino acid changes in the M2 and NP proteins, respectively, which warrants further investigation regarding the role of those amino acids in relation to host adaptation.
The remaining four internal genes, PB2, PB1, PA, and NS, were similar to the composition of the contemporary swine TRIG (data not shown).
To our knowledge the new isolates are the first swine and pandH1N1 reassortant identified in the U.S. The reassortment of pan-H1N1 with swine influenza viruses indicates the importance of systematic surveillance of swine population to determine the origin, the prevalence of similar reassortants in the U.S. and their impact on both swine production and public health.
The two different alleles present in the could be due to the effect of evolution and natural selection because the same can be found in chimps.4 The PV92 locus does not code for any protein but rather involves an Alu element that is 300-bp long. A person with the “+” allele would have the Alu element, making that sequence longer while those with the “-“ allele don’t have the element and would have a shorter sequence. This locus can be found on chromosome 16.3 There are multiple Alu sequences found among primate genomes but there are human specific sequences such as the one found on the PV92 locus.1 In the experiment, student DNA was collected from cheek cells and PCR was used to target the loci and amplify the region of DNA. In the taster gene, after amplification, a restriction digest was performed to differentiate between the two alleles. The digest was able to show differentiation because those with the “T” allele would have two bands from gel electrophoresis and those with “t” would have one band because the restriction enzyme doesn’t cut it.
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...
A pandemic is defined as a disease that has the ability to outbreak and spread globally. A pandemic is determined by how a particular disease spreads rather than how many lives it has claimed. A future pandemic can easily occur if and when a mutation of a new influenza A virus emerges. A pandemic of this type is easily possible to spread quickly and globally due to that when a new strand of the virus emerges, it will be highly unlikely that the human population will have a built up immunity to it.
All references and resources are taken from the Public Library of Science, Biology March 2004 issue and from Science March 16, 2004
These pieces of history may have faded from memory, but with the upcoming threat of an avian flu that can jump from human to human, people must learn from the past to combat the future. From the time of its first recorded incident in 412 BC (Adams 1) to 1918, influenza was never taken seriously. With symptoms similar to the common cold, most people disregarded influenza as a minor illness, nothing more. As Lynette Iezzoni quoted in her book, Influenza 1918, influenza was thought to be “quite a Godsend! Everybody ill, nobody dying” besides the very old and feeble (16).
Tumpey, T. M. (2005). Characterization Of The Reconstructed 1918 Spanish Influenza Pandemic Virus. Science, 310(5745), 77-80.
At no time was a search for the cure for influenza more frantic than after the devastating effects of the pandemic of 1918. The pandemic killed somewhere between twenty and a hundred million people, making it twenty five times more deadly than the ordinary cough and sneeze flu. The symptoms of this flu were like something straight out of a horror movie: the victim’s facial complexion changed to a dark, brownish purple, the feet turned black, and they began to cough up blood. Eventually, death was caused, literally by drowning, when the victim’s lungs filled with their own blood. The first scientist to claim to solve the enigma of influenza was Dr. Friedrich Johann Pfeiffer. He isolated a bacterium he named Hemophilus influenzae from the respiratory tract of those who had the flu in the pandemic of 1890. He was believed to be correct in his discovery until the pandemic of 1918, when scientists searched the respiratory tracts of influenza victims and only sometimes found his bacterium. Robert E. Shope and his mentor Paul Lewis were the next to attempt to crack the code of influenza. They chose to study the disease in pigs, a controversial choice because many people believed that the swine influenza pigs were contracting was not the same as the human flu. The first experiment they ran was ba...
The Influenza Pandemic of 1918 had a major effect on the public health in America at the time. Coordination between different levels and branches of government improved communication regarding the spread of influenza, improved the amount of people in hospitals, increased the spread of vaccines, and led to improvements in infection control and containment of the flu. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1997248/).
In order to figure out the genes responsible, there are several other factors that must be determined. These factors include the number of genes involved, if each gene is x-linked or autosomal, if the mutant or wild-type allele for each is dominant, and if genes are linked or on different chromosomes. Proposed crosses include reciprocal crosses between the pure-breeding mutants of strains A and B with the wild-type will help determine if the genes or sex-linked or autosomal, in addition to which alleles are dominant (8). Another proposed cross includes complementation crosses between pure-breading mutants from strains A and B to determine if one or two genes are involved (8). Furthermore, testcrosses between F1 progeny and pure-breeding recessive mutants from strains A and B, which will help determine if genes are linked on the chromosome or if they assort independently (8). These proposed crosses are shown in the attached
A few years before 1918, in the height of the First World War, a calamity occurred that stripped the globe of at least 50 million lives. (Taubenberger, 1918) This calamity was not the death toll of the war; albeit, some individuals may argue the globalization associated with the First World War perpetuated the persistence of this calamity. This calamity was referred to the Spanish Flu of 1918, but calling this devastating pestilence the “Spanish Flu” may be a historical inaccuracy, as research and historians suggest that the likelihood of this disease originating in Spain seams greatly improbable. Despite it’s misnomer, the Spanish Flu, or its virus name H1N1, still swept across the globe passing from human to human by exhaled drops of water that contained a deadly strand of RNA wrapped with a protein casing. Individuals who were unfortunate enough to come in contact with the contents of the protein casing generally developed severe respiratory inflammation, as the Immune system’s own response towards the infected lung cells would destroy much of the lungs, thus causing the lungs to flood with fluids. Due to this flooding, pneumonia was a common cause of death for those infected with Spanish Flu. Due its genetic similarity with Avian Flu, the Spanish Flu is thought to be descended from Avian Flu which is commonly known as “Bird Flu.” (Billings,1997) The Spanish Flu of 1918 has had a larger impact in terms of global significance than any other disease has had because it was the most deadly, easily transmitted across the entire globe, and occurred in an ideal time period for a disease to happen.
Researchers from the Animal Parasitic Laboratory and Agriculture Research Service of the United States Department of Agriculture concluded that the linage of Trichinella spiralis originated from Europe over several thousand years ago (Rosenthal, LaRosa, Zarlenga, Dumans, Chunyu, Mingyuan & Pozio, 2008). This is the approximate time when pigs were first domesticated in that region. This implies that the species Trichinella spiralis was introduced to the Americas from pigs. However, there is evidence that the early people of this world, hominid hunters, have consumed foodborne parasites by hunting wild game from millions of years before. Today, swine is governed on the ensuing transmission, and evolutionary diversification.
Hvistendahl, M, Cohen, J et. al. 2013. ‘New Flu Virus in China Worries and Confuses’ Science 340: 129-130
In order to decide whether or not the swine flu vaccine is completely necessary, one must first gain a better understanding of the topic. It is a scientifically known fact that the swine flu is a result of a virus. A virus is a capsule of genetic material that causes infection in the body. The infectious particles are made up of nucleic acid enclosed in a protein shell, called a capsid. It cannot be considered a living organism like the disease causing agent of bacteria, because it does not carry out all the characteristics of life. Specifically, it cannot reproduce on its own.
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.
According to the Swine flu investigation team on April 15 and April 17, 2009, novel swine-origin influenza A (H1N1) virus (S-OIV) was isolated from two epidemiologically unlinked patients in the United States. The same strain was identified in other countries such as Mexico and Canada. In the United States 60% of patients were 18 years of age or younger suggesting that the younger population was more susceptible to the transmission of S-OIV or the possibility that the older population had developed a small amount of antibodies from the 1976 swine influenza vaccine (H1N1). 18% of the patients had recently traveled to Mexico, and 16% were identified from school outbreaks. (France, Jackson & Schrag, 2010) The most common presenting symptoms were fever (94% of patients), cough (92%), and sore throat (66%); 25% of patients had diarrhea, and 25% were experiencing emesis. Therefore, the criteria characterizing the S-OIV infection are comparable to the ...