• H1N1
  • The World Health Organization declared an outbreak of a new type of influenza A/H1N1 to be a pandemic in June 2009. (wikipedia.org)
  • Those over 65 appear to be at lower risk because of exposure to the H1N1 type, which is the same as the 1918 flu. (blogspot.com)
  • On 11 June 2009, a new strain of H1N1 influenza was declared to be a global pandemic (Stage 6) by the WHO after evidence of spreading in the southern hemisphere. (wikipedia.org)
  • The 13 November 2009 worldwide update by the WHO stated that "[a]s of 8 November 2009, worldwide more than 206 countries and overseas territories or communities have reported [503,laboratory confirmed cases of pandemic influenza H1N1 2009, including over 6,250 deaths. (wikipedia.org)
  • viral
  • Infections can be further classified by causative agent (bacterial, viral, fungal, parasitic), and by the presence or absence of systemic symptoms (sepsis). (wikipedia.org)
  • People have been worried for years about potential new viral pandemics, such as avian influenzas. (medindia.net)
  • Complications of influenza may include viral pneumonia, secondary bacterial pneumonia, sinus infections, and worsening of previous health problems such as asthma or heart failure. (wikipedia.org)
  • Using the virus' genome sequence, whose final three genes are being published simultaneously this week in Nature, Tumpey's group created a live virus with all eight of the Spanish flu viral genes. (bio-medicine.org)
  • To make the virus, the researchers used an approach called "reverse genetics," which involves transferring gene sequences of viral RNA into bacteria and then inserting combinations of the genes -- often after manipulating them -- into cell lines, where they combine to form a virus. (bio-medicine.org)
  • Then, they sent the bacteria containing the viral gene sequences to Tumpey, who inserted them into the cells to produce the virus. (bio-medicine.org)
  • The two main classes of antiviral drugs used against influenza are neuraminidase inhibitors, such as zanamivir and oseltamivir, or inhibitors of the viral M2 protein, such as amantadine and rimantadine. (wikipedia.org)
  • The real reason that the flu epidemic of 1918 to 1919 killed so many people was not simply because of this viral infection but because a relatively new drug, called aspirin, was used in large amounts. (mercola.com)
  • Influenza type A viruses are categorized into subtypes based on the type of two proteins on the surface of the viral envelope: H = hemagglutinin, a protein that causes red blood cells to agglutinate. (wikipedia.org)
  • He was the first to identify the biological role of the non-structural NS1 Influenza Protein during infection, the first to describe and provide a molecular analysis of a viral-encoded IFN antagonist among negative strand RNA viruses, and the first to demonstrate that the M1 protein of the influenza virus determines its morphology. (wikipedia.org)
  • In 2001, he co-organized the International Course on Viral Vectors in Heidelberg, Germany, which was sponsored by the Federation of European Biochemical Societies (FEBS), as well as the first Research Conference on Orthomyxoviruses, also in 2001, which was held in the Netherlands and sponsored by the European Scientific Working Group on Influenza. (wikipedia.org)
  • Viral infections in animals provoke an immune response that usually eliminates the infecting virus. (wikipedia.org)
  • Some viruses including those that cause AIDS and viral hepatitis evade these immune responses and result in chronic infections. (wikipedia.org)
  • Although Louis Pasteur and Edward Jenner developed the first vaccines to protect against viral infections, they did not know that viruses existed. (wikipedia.org)
  • Although viruses can differ with respect to many phenotypes, phylodynamic studies have to date tended to focus on a limited number of viral phenotypes. (wikipedia.org)
  • The relative lengths of internal versus external branches will be affected by changes in viral population size over time (see figure 1) Rapid expansion of a virus in a population will be reflected by a "star-like" tree, in which external branches are long relative to internal branches. (wikipedia.org)
  • Compared to a phylogeny of an expanding virus, a phylogeny of a viral population that stays constant in size will have external branches that are shorter relative to branches on the interior of the tree. (wikipedia.org)
  • The phylogeny of hepatitis B virus (caricatured by figure 1B) instead reflects a viral population that has remained roughly constant in size. (wikipedia.org)
  • The clustering of taxa on a viral phylogeny will be affected by host population structure (see figure 2) Viruses within similar hosts, such as hosts that reside in the same geographic region, are expected to be more closely related genetically if transmission occurs more commonly between them. (wikipedia.org)
  • Tree balance will be affected by selection, most notably immune escape (see figure 3) The effect of directional selection on the shape of a viral phylogeny is exemplified by contrasting the trees of influenza virus and HIV's surface proteins. (wikipedia.org)
  • The social history of viruses describes the influence of viruses and viral infections on human history. (wikipedia.org)
  • The rare epidemics of viral diseases originating in animals would have been short-lived because the viruses were not fully adapted to humans and the human populations were too small to maintain the chains of infection. (wikipedia.org)
  • epidemics
  • Either way, the mortality rate was about 2.5 percent, compared with less than 0.1 percent during the routine influenza epidemics to which we have become accustomed. (managedcaremag.com)
  • That's close to the average number of excess deaths (the difference between the number of deaths observed in a group and the number of deaths that would have occurred if the group had the same death rate as a comparison population) attributed to influenza in recent years from U.S. epidemics, though. (managedcaremag.com)
  • In contrast to the regular seasonal epidemics of influenza, these pandemics occur irregularly-there have been about 9 influenza pandemics during the last 300 years. (wikipedia.org)
  • Epidemics caused by viruses began when human behaviour changed during the Neolithic period, around 12,000 years ago, when humans developed more densely populated agricultural communities. (wikipedia.org)
  • The viruses were later carried to the New World by Europeans during the time of the Spanish Conquests, but the indigenous people had no natural resistance to the viruses and millions of them died during epidemics. (wikipedia.org)
  • fever
  • When the virus is inhaled, it attacks cells in the upper respiratory tract, causing typical flu symptoms such as fatigue, fever and chills, a hacking cough, and body aches. (encyclopedia.com)
  • Typical influenza symptoms include the abrupt onset of a headache, dry cough, and chills, rapidly followed by overall achiness and a fever that may run as high as 104 ° F (40 ° C). As the fever subsides, nasal congestion and a sore throat become noticeable. (encyclopedia.com)
  • If a person takes a fever-lowering drug, the body doesn't secrete this antiviral chemical as much, enabling the virus to overwhelm the sick person. (mercola.com)
  • When the human body is exposed to a flu virus, the body inflames into a fever as a defensive effort to fight the virus. (mercola.com)
  • cough
  • Influenza is an acute respiratory illness caused by an RNA virus from the Orthrosynovitic family, of which three serotypes are known (A, B and C). Influenza causes an acute febrile illness with myalgia, headache and cough. (blogspot.com)
  • immunity
  • It's speculated that older people had acquired some immunity from two suspected pandemics in the 19th century, while younger people's immune systems hadn't matured to the point to trigger a fatal immune response to this particular virus. (managedcaremag.com)
  • deaths
  • In the United States, 90% of all deaths from influenza occur among persons older than 65. (encyclopedia.com)
  • Looking at flu seasons, which span calendar years, NIH epidemiologists recently estimated that during the decade ending in 1998-1999, the mean number of influenza-associated deaths in the United States was 51,203. (managedcaremag.com)
  • In general, though, the trend since 1976-1977 has been for influenza-associated deaths to increase, which is attributed in part to the aging of the population. (managedcaremag.com)
  • bacteria
  • Historically, influenza was ascribed to a number of different agents, including "bad air" and several different bacteria. (encyclopedia.com)
  • These agents are bacteria, viruses, fungi, or toxins, and may be in a naturally occurring or a human-modified form, in much the same way in biological warfare. (wikipedia.org)
  • According to the U.S. Centers for Disease Control and Prevention, bioterrorism is the deliberate release of viruses, bacteria, toxins or other harmful agents to cause illness or death in people, animals, or plants. (wikipedia.org)
  • The origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids-pieces of DNA that can move between cells-while others may have evolved from bacteria. (wikipedia.org)
  • World Health Organ
  • Dr. Klaus Stohr, the head of the influenza program at the World Health Organization who is also leading the agency's fight against SARS said in a Wall Street Journal interview, "We are not prepared for the devastation of a flu pandemic… SARS will be something to smile about," he said. (wkbw.com)
  • occur
  • An opportunistic disease requires impairment of host defenses, which may occur as a result of genetic defects (such as Chronic granulomatous disease), exposure to antimicrobial drugs or immunosuppressive chemicals (as might occur following poisoning or cancer chemotherapy), exposure to ionizing radiation, or as a result of an infectious disease with immunosuppressive activity (such as with measles, malaria or HIV disease). (wikipedia.org)
  • Influenza type A viruses are very similar in structure to influenza viruses types B and C. The virus particle (also called the virion) is 80-120 nanometers in diameter and usually roughly spherical, although some rare filamentous forms can occur. (wikipedia.org)
  • Influenza pandemics occur when a new strain of the influenza virus is transmitted to humans from another animal species. (wikipedia.org)
  • In contrast, a more balanced phylogeny may occur when a virus is not subject to strong immune selection or other source of directional selection. (wikipedia.org)
  • evolves
  • The Influenza Genome Sequencing Project was initiated in 2004 to create a library of influenza sequences to understand what makes one strain more lethal than another, what genetic determinants most affect immunogenicity , and how the virus evolves over time. (wikipedia.org)
  • adults
  • The 1918 Spanish flu was a global disaster, killing an estimated 20 to 50 million people, many of them otherwise healthy adults. (bio-medicine.org)
  • Other studies suggest that these agents might be able to 'roll back' the self-damaging host response of young adults to the less damaging response of children and thus save lives. (wiley.com)
  • molecular
  • These pathways include several molecular targets that are up-regulated in acute lung injury and down-regulated by anti-inflammatory and immunomodulatory agents, including statins, fibrates, and glitazones. (wiley.com)
  • His research interest has been focused on the molecular biology of influenza viruses and several other negative-strand RNA viruses. (wikipedia.org)
  • bacterial
  • Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants, and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, about 5,000 virus species have been described in detail, although there are millions of types. (wikipedia.org)
  • strain
  • A report published in early 2003 noted that Type A influenza virus has a high potential for use as such an agent because of the virulence of the Type A strain that broke out in Hong Kong in 1997 and the development of laboratory methods for generating large quantities of the virus. (encyclopedia.com)
  • Therapies against a new flu strain would need to disarm the parts of the virus that do the most damage to the body. (bio-medicine.org)
  • birds
  • Typically, influenza is transmitted from infected mammals through the air by coughs or sneezes, creating aerosols containing the virus, and from infected birds through their droppings. (wikipedia.org)
  • propagation
  • The propagation of influenza viruses throughout the world is thought in part to be by bird migrations, though commercial shipments of live bird products might also be implicated, as well as human travel patterns. (wikipedia.org)
  • therapies
  • In order to learn which components of the virus would be the best targets for such therapies, Terrence Tumpey of the Centers for Disease Control and Prevention and his colleagues revisited the 1918 Spanish flu virus. (bio-medicine.org)
  • Treatments for influenza include a range of medications and therapies that are used in response to disease influenza. (wikipedia.org)
  • Spanish
  • They spliced these sequences together with noncoding DNA from a closely related virus, since this portion of the genome wasn't available for the Spanish flu virus. (bio-medicine.org)
  • The researchers also produced variations of the virus for comparison, with certain Spanish flu genes replaced by the corresponding genes from other flu viruses. (bio-medicine.org)
  • Then they studied the viruses' effects in mice, chick embryos and human lung cells and identified the constellation of genes that was responsible for the Spanish flu virus' extreme virulence. (bio-medicine.org)
  • The Spanish flu pandemic of 1918, for example, killed more than 40 million people worldwide (670,000 Americans alone). (wkbw.com)
  • humans
  • The use of agents that do not cause harm to humans but disrupt the economy have been discussed. (wikipedia.org)
  • Viruses of plants and livestock also increased, and as humans became dependent on agriculture and farming, diseases such as potyviruses of potatoes and rinderpest of cattle had devastating consequences. (wikipedia.org)
  • Having evolved from viruses that infected other animals, they first appeared in humans in Europe and North Africa thousands of years ago. (wikipedia.org)
  • Over the past 50,000-100,000 years, as modern humans increased in numbers and dispersed throughout the world, new infectious diseases emerged, including those caused by viruses. (wikipedia.org)
  • The virus, which only infected humans, probably descended from the poxviruses of rodents. (wikipedia.org)
  • Humans probably came into contact with these rodents, and some people became infected by the viruses they carried. (wikipedia.org)
  • When viruses cross this so-called "species barrier", their effects can be severe, and humans may have had little natural resistance. (wikipedia.org)
  • Most viruses are species-specific and would have posed no threat to humans. (wikipedia.org)
  • Herpes viruses first infected the ancestors of modern humans over 80 million years ago. (wikipedia.org)
  • fatal
  • These agents also help reverse the mitochondrial dysfunction that accompanies multi-organ failure, something often seen in fatal Influenza. (wiley.com)