 |
|
The host makes all the difference
March 27, 2009Braunschweig Helmholtz researchers demonstrate the role of the host in influenza illnesses
"Where there are many scientific works dealing solely with the flu virus, we have investigated how the host reacts to an infection," says Klaus Schughart, head of the Experimental Mouse Genetics research group. In infection experiments the researchers have now discovered that an excessive immune response is responsible for the fatal outcome of the disease in mice. This overreaction has genetic roots. The findings have now been published in the scientific magazine PLoS One.
For their investigations the researchers injected seven different inbred mouse strains with the same quantity of type Influenza A flu viruses. All of the animals within one mouse strain are genetically identical, like identical twins. However, one strain differs from another just like different individuals in the human population. To their surprise, the researchers were able to identify strong differences in the progression of the influenza between the seven strains. In five of the strains the illness was mild: the animals lost weight, recovering completely after seven to eight days. However, in two of the mouse strains the animals lost weight rapidly and died after just a few days.
The researchers looked for reasons for these differences: they investigated how the immune system of the animals responds to the virus. "The mice die from their own immune defences, which are actually supposed to protect them against the virus. The immune system produces too many messengers, which have a strong activating effect on the immune cells. These cells then kill tissue cells in the lungs that are infected with the virus," says Schughart. At the same time, these overactive cells also destroy healthy lung tissue. In mice that died the researchers also found one hundred times more viruses than in animals that survived. "It appears that the animals have specific receptors on their cells that make them more receptive to a severe viral infection." Flu infections in humans could take a similar course, here too, genetic factors could favour a severe progression of the illness. "It is only now that we are beginning to understand the role played by the genetic factors of the host and what increased receptiveness means in the case of influenza," says Schughart.
Every year between 10,000 and 30,000 people in Germany die from influenza, the majority via pathogens of the Influenza A type. There are various sub-types of the main type A, in which the composition of the virus envelope differs. H1N1 and H3N2 are the most widely-distributed flu strains amongst humans, H5N1 the familiar avian flu virus. The H stands for the protein haemagglutinin, with which the virus latches onto the cells of the airways, infecting them. In order for the newly-created flu viruses to leave the host cells, in turn, they require neuraminidase (N). To evade an immune response the virus changes the H and N characteristics constantly. Sometimes light, sometimes heavy: the result is a completely new virus type with a new number, with the consequences generally a severe global flu pandemic.
Helmholtz Association of German Research Centres
The researchers looked for reasons for these differences: they investigated how the immune system of the animals responds to the virus. "The mice die from their own immune defences, which are actually supposed to protect them against the virus. The immune system produces too many messengers, which have a strong activating effect on the immune cells. These cells then kill tissue cells in the lungs that are infected with the virus," says Schughart. At the same time, these overactive cells also destroy healthy lung tissue. In mice that died the researchers also found one hundred times more viruses than in animals that survived. "It appears that the animals have specific receptors on their cells that make them more receptive to a severe viral infection." Flu infections in humans could take a similar course, here too, genetic factors could favour a severe progression of the illness. "It is only now that we are beginning to understand the role played by the genetic factors of the host and what increased receptiveness means in the case of influenza," says Schughart.
Every year between 10,000 and 30,000 people in Germany die from influenza, the majority via pathogens of the Influenza A type. There are various sub-types of the main type A, in which the composition of the virus envelope differs. H1N1 and H3N2 are the most widely-distributed flu strains amongst humans, H5N1 the familiar avian flu virus. The H stands for the protein haemagglutinin, with which the virus latches onto the cells of the airways, infecting them. In order for the newly-created flu viruses to leave the host cells, in turn, they require neuraminidase (N). To evade an immune response the virus changes the H and N characteristics constantly. Sometimes light, sometimes heavy: the result is a completely new virus type with a new number, with the consequences generally a severe global flu pandemic.
Helmholtz Association of German Research Centres
Influenza Current Events and Influenza News RSSAmid the flu epidemic, don't forget RSV in young children
Influenza, particularly H1N1, has understandably captured the attention of public health officials, the media and the public.
Multiple health concerns surface as winter, vitamin D deficiences arrive
A string of recent discoveries about the multiple health benefits of vitamin D has renewed interest in this multi-purpose nutrient, increased awareness of the huge numbers of people who are deficient in it, spurred research and even led to an appreciation of it as "nature's antibiotic."
Asthma a significant risk factor for complications in children with H1N1
A new study on pediatric H1N1 influenza admissions has found that asthma is a significant risk factor for severe disease in children with pandemic H1N1 compared with the seasonal flu.
Preventing H1N1 spread to health care workers: Dilemma, debate and confusion
A commentary in the December issue of The Lancet Infectious Diseases brings to light the gaps in knowledge on the transmission of a common pathogen - the influenza virus - and its impact on decisions about how best to protect health care workers.
New culprit for viral infections among elderly -- an overactive immune response
Researchers at Yale School of Medicine have found that exaggerated responses of the immune system explain why the elderly succumb to viral infections more readily than younger people.
New research helps explain why bird flu has not caused a pandemic
Bird flu viruses would have to make at least two simultaneous genetic mutations before they could be transmitted readily from human to human, according to research published today in PLoS ONE.
Mechanical ventilation for patients with lung damage don't always work as planned
As more Canadians are diagnosed with H1N1 influenza infection, some will be admitted to hospital. The most severely affected may be treated in the intensive care unit (ICU) and placed on a mechanical ventilator to help them breathe while they recover from the infection.
Researchers mobilizing global resources to test new treatments for severe H1N1 infection
An important, ground-breaking initiative is unfolding in the global critical care community in response to the H1N1 pandemic.
Worksite wellness programs may reduce employee absenteeism
Emory University Rollins School of Public Health researchers will present Nov. 11 on a range of topics at the American Public Health Association's annual meeting in Philadelphia, including a study that found reduced absenteeism among employees participating in a large-scale worksite wellness program.
U.S. and European Experts Applaud Creation of New Transatlantic Task Force on Global Antibiotic Resistance Threat
Experts on both sides of the Atlantic applaud President Barack Obama and Swedish Prime Minister Fredrik Reinfeldt, representing the European Union (EU) Presidency, for establishing a transatlantic task force to address antibiotic resistance, an urgent and growing problem that threatens patient safety and public health worldwide.
More Influenza Current Events and Influenza News Articles
 |
The Great Influenza: The story of the deadliest pandemic in history by John M. Barry (Author) At the height of WWI, history’s most lethal influenza virus erupted in an army camp in Kansas, moved east with American troops, then exploded, killing as many as 100 million people worldwide. It killed more people in twenty-four months than AIDS killed in twenty-four years, more in a year than the Black Death killed in a century. But this was not the Middle Ages, and 1918 marked the first collision of science and epidemic disease. Magisterial in its breadth of perspective and depth of research and now revised to reflect the growing danger of the avian flu, The Great Influenza is ultimately a tale of triumph amid tragedy, which provides us with a precise and sobering model as we confront the epidemics looming on our own horizon. John M. Barry has written a new ... |
 |
A Cruel Wind: Pandemic Flu in America 1918-1920 by Dorothy A. Pettit (Author) The flu pandemic that began in 1918 touched with illness virtually every family in America. It was a devastating time, far overshadowing the carnage of World War I as the pandemic killed more people in less time than any disease before or since. With 25% to 30% of the worlds population having clinically apparent illnesses and a mortality rate of 2.5% - 5%, it is believed that more than 675,000 Americans were among the 50-100 million that died worldwide. Because many experts believe that it is not a matter of if the world will encounter another 1918-like flu pandemic, but when, this social history of the pandemic should be considered essential reading for students, public health officials, doctors, nurses, journalists, and those in government office, interested in learning what workedand... |
 |
Flu : The Story Of The Great Influenza Pandemic by Gina Kolata (Author) A scientific history of the Great Flu Epidemic of 1918, which killed at least 40 million people. The author details the science and latest understanding of flu, examines the chances of a great epidemic recurring and explores what can be done to prevent it. |
 |
Flu: A Social History of Influenza by Tom Quinn (Author) It may sound innocuous compared to war, plague and famine, but flu is in fact one of the world's biggest killers. Strains of the virus are always in circulation but every so often a new and particularly virulent one comes along, to which we have no historic immunity - when that happens the consequences are devastating. This fascinating book explores the havoc caused by the world's most deadly virus - and the destruction left in its wake. From its initial identification by the Greek physician Hippocrates in the 4th century BC to the Spanish flu pandemic of 1918 and beyond, Tom Quinn explores the social, medical and scientific ramifications of the major outbreaks that have occurred over the centuries - and the potential consequences should such a pandemic occur in the modern world, an event... |
 |
Influenza Virology: Current Topics by Yoshihiro Kawaoka (Author) |
 |
The Devil's Flu: The World's Deadliest Influenza Epidemic and the Scientific Hunt for the Virus That Caused It by Pete Davies (Author) A gripping account of the 1918 flu pandemic and the modern-day hunt for this elusive and deadly virus In 1918, a flu virus more lethal than any that has come along since swept through the world, from the remotest villages in Arctic climates to crowded U.S.cities to the battlefields of Europe, killing forty million people. Yet, despite its devastating toll and the probability that other deadly pandemics await on the horizon, it was relegated to a footnote in history. The Devil's Flu is the extraordinary story of 1918's forgotten tragedy and of the global scientific community's effort to avert another such disaster. The 1918 flu still so intrigues and frightens experts in the field that in 1998, a group of respected scientists journeyed to the Norwegian Arctic Circle in search... |
 |
American Experience - Influenza 1918 Starring: David McCullough, David Ogden Stiers, Joe Morton, Liev Schreiber, Linda Hunt Also With: Katy Mostoller (Producer), Michael Rossi (Producer), Rocky Collins (Producer), Rocky Collins (Writer), Tracy Heather Strain (Producer), Henry Hampton (Writer) As the nation mobilized for war in the spring of 1918, ailing Private Albert Gitchell reported to an army hospital in Kansas. He was diagnosed with the flu, a disease about which doctors knew little. Before the year was out, America would be ravaged by a flu epidemic that killed 675,000 people--more than died in all the wars of this century combined--before disappearing as mysteriously as it began. |
 |
America's Forgotten Pandemic: The Influenza of 1918 by Alfred W. Crosby (Author) Between August 1918 and March 1919 the Spanish influenza spread worldwide, claiming over 25 million lives, more people than those perished in the fighting of the First World War. It proved fatal to at least a half-million Americans. Yet, the Spanish flu pandemic is largely forgotten today. In this vivid narrative, Alfred W. Crosby recounts the course of the pandemic during the panic-stricken months of 1918 and 1919, measures its impact on American society, and probes the curious loss of national memory of this cataclysmic event. In a new edition, with a new preface discussing the recent outbreaks of diseases, including the Asian flu and the SARS epidemic, America's Forgotten Pandemic remains both prescient and relevant. Alfred W. Crosby is a Professor Emeritus in American Studies,... |
 |
Pandemic Influenza: Emergency Planning and Community Preparedness by Jeffrey R. Ryan (Editor) The swine flu emergency needn’t become a crisis. This critically acclaimed work provides public health officials, doctors, responders, and emergency planners with accurate current information that will help them understand the nature of an outbreak, assess risk, answer public concerns, and develop informed strategies. Devoid of sensationalism and agenda, this CRC Press resource provides all the information needed to understand pandemic influenzas including, avian, swine, and human variations and outlines the steps needed to develop and implement prevention, stabilization, and recovery efforts as needed at the local level. ... an amazing resource ... Dr. Ryan has assembled some of the best experts in the field to guide you in understanding... |
 |
Rapid Reference to Influenza by Jan Wilschut (Author), Janet Mcelhaney (Author), Abraham Palache (Author) |
| © 2009 BrightSurf.com |