November 9, 2009 Bioe 109 Fall 2009 Lecture 19 Evolution and human health. The evolution of flu viruses
|
|
- Esmond Hudson
- 5 years ago
- Views:
Transcription
1 November 9, 2009 Bioe 109 Fall 2009 Lecture 19 Evolution and human health The evolution of flu viruses - the potential harm of disease epidemics in human populations has received considerable attention lately. - it is clear that diseases can be spread throughout the world at a rapid rate and this certainly sets the stage for a global pandemic to spread well before we can contain it. - a growing number of evolutionary biologists have recently begun to study the evolution of viruses. - we ve already discussed the rapid evolution of the HIV-1 virus. - today, we ll consider the evolution of the influenza A virus. - the influenza A virus is responsible for the annual flu epidemics we experience each year. - it also has been responsible for the occasional global pandemics that in the past century have occurred in 1918, 1957 and flu is not recognized as a deadly disease but it is. - in the US, it now kills about 30,000 35,000 people each year. - especially virulent strains have been responsible for large numbers of deaths. - the most deadly pandemic in the past 100 years occurred in this was called the Spanish flu. - estimates of the number of deaths caused by the Spanish flu range from 50 million to 100 million people. - the Spanish flu certainly didn t originate in Spain. - by May 1918, it was spreading on both sides of the European frontline during WWI. - then it seemed to subside. - by late summer it reappeared and spread with deadly speed. - within a period of months it had sickened some 20% of the world s population. - the complete sequence of the 1918 virus was published in fall it was isolated from two sources from slices of lung tissues isolated by pathologists from flu victims in a military hospital in Fort Jackson, South Carolina. - the second source was from a mass grave in a remote village in Alaska where a female body was found that had intact lung tissue. - the virus has been reconstructed by reverse genetics and tested in mice and chickens. - the origin of the 1918 H1N1 virus remains unknown, but many flu researchers think it may have originated from a bird species (that has yet to be identified). - the complete sequence of the 1918 virus might provide new insights into battling the next pandemic. - the influenza A virus is a retrovirus that encodes a total of 11 proteins (coding for coat proteins, structural proteins and polymerases).
2 - its genome is composed of 8 RNA molecules. - the predominant coat protein is called hemagglutinin this is the key protein through which our immune system primary identifies and attacks the virus. - in order to be transmitted from host to host the flu virus needs to find a steady supply of hosts that have never been exposed to its version of hemagglutinin. - the specific sites that the immune system recognizes and remembers (through memory cells) are called antigenic sites. - sites that are not recognizable by the immune system are called non-antigenic sites. - flu strains with novel antigenic mutations should enjoy a selective advantage over other strains because they represent a novel challenge to the immune system. - one can study the evolution of viruses very easily for two reasons. - first, they evolve extremely rapidly - the influenza A virus evolves a million times faster than humans. - second, they can be preserved in the freezer and then rethawed at a future date for genetic analysis. - one recent study examined the phylogenetic relationships among flu viruses sampled over the period of 1968 to this 20-year period is equivalent to 20 million years of human evolution (and we have diverged from the lineage leading to chimpanzees only 5 million years ago). - a study by Walter Fitch et al. (1991) studied the hemagglutinin gene in this temporal sample. - two interesting patterns were apparent. 1. a constant rate of divergence with time. - the strains accumulated changes in their hemagglutinin proteins at a constant rate of about 6.7 x 10-3 substitutions per site per year. - although this is consistent with a clock-rate substitution of neutral alleles, it is more likely caused by strong (and consistent) natural selection. 2. most strains represented extinct side branches on the phylogeny - interestingly, all strains studied were closely related and derived from a single ancestral strain present in the late 1960 s. - other stains present at this time left no descendants. - what allowed this one lineage to survive while the others dies out? - the answer appears to be antigenic mutations. - a total of 109 amino acid replacement mutations were present. surviving lineage extinct lineage in antigenic sites in non-antigenic sites
3 - over 3/4 of the mutations found in the surviving lineages occurred at antigenic sites. - this suggests that antigenic mutations have played an important role in the long-term survival of flu strains. - a follow up study examined 357 flu strains collected over the period of 1985 and a total of 331 substitutions were identified. - of these, 191 (58%) were silent mutations and 140 (42%) were replacement mutations. - this is not too different than expected under a neutral model of evolution. - however, non-neutral changes were observed at 18 amino acid sites. - one powerful way to test for the action of natural selection at a protein is to compare the rate of non-synonymous substitutions (ka) to the rate of synonymous substitutions (ks). ka = rate of non-synonymous substitution ks = rate of synonymous substitution - since most non- synonymous changes are deleterious, the ratio of ka/ks should be less than unity. - this demonstrates the action of purifying selection. - when the ratio of ka/ks exceeds one it indicates that more non- synonymous changes are occurring than synonymous changes. - this is called positive selection. ka/ks < 1 ka/ks > 1 purifying selection positive selection - within the hemagglutinin gene there were 18 sites experiencing elevated rates of replacement substitutions, i.e., ka/ks ratios greater than 1. - all 18 involved antigenic sites. - this strongly implies the action of selection favoring mutations at the these sites - why is the information useful? - because it allows the manufacturers of flu vaccines to make a more reasonable guess about which circulating flu strains will be the next season s epidemic. - these would be the strains that have the most number of replacement changes at these 18 antigenic sites. - this allowed the researchers to correctly predict the epidemic strain in 9 out of 11 recent flu seasons. The origin of pandemic flu strains - the phylogeny of human flu strains suggests that viruses with radically different hemagglutinin genes could attain a major fitness advantage and cause a pandemic. - how can this occur?
4 - by the process of recombination that may occur when two flu strains simultaneously infect the same host cell. - when this happens, some of the RNA strands can mix between strains. - phylogenies based on different flu genes shows convincing evidence that this process does occur. - figure 14-7 is a phylogeny based on the flu s nucleoprotein gene. - distinct clades are present that are found in different groups - there are equine strains, human strains, etc. - within the clade of human strains are some interesting exceptions. - the H3N2 strain has a nucleoprotein gene similar to other human strains but hemagglutinins that are distantly related. - how did this occur? - apparently by lateral gene transfer. - before 1968, no H3 gene had ever been found in viruses infecting humans. - so where did this H3 gene come from? - figure 14-8 shows that it likely came from birds. - how did a human flu strain acquire a H3 gene from birds? - the most reasonable hypothesis is that it occurs within a different host - pigs. - a human strain and a bird strain simultaneously infect a pig, swap genes, then it later jumps back to humans. - alternatively, an avian strain and human strain infecting the same cell can recombine and produce a highly novel and virulent pathogen. - both the 1957 and 1968 viruses were avian/human reassortants in which 2-3 RNA avian segments were added to the then-circulating human-adapted virus. The avian flu threat - we are currently experiencing the first flu pandemic of the 21 st century. - in many ways, we are fortunate that the H1N1 (swine) flu is not more virulent it is killing about the same percentage as the normal seasonal flu. - a much greater danger is the avian flu (H5N1). - this virus is frighteningly lethal in chickens, which can die within hours of exposure. - it also is highly dangerous to humans and other mammals roughly half of people infected with H5N1 die. - in May 1997, an outbreak of the H5N1 virus occurred among chickens in Hong Kong. - this wasn t unusual in any way and did not cause much concern avian flus do not jump to humans. - however, this one broke the rules. - that same month a 3 year old boy was admitted to a Hong Kong hospital with a cough and a fever. - his symptoms worsened quickly even though he was put on a ventilator and given numerous antibiotics. - within 6 days he was dead.
5 - pathologists were astonished when swabs from the boy s windpipe yielded a H5N1 virus. - it turned out to be the same virus that had infected the local chickens. - this death looked like a fluke until another 17 people checked into hospitals around Hong Kong with similar symptoms that were also confirmed as H5N1. - many of these victims had either visited or worked in Hong Kong s live-poultry markets. - public health experts descended on the city and persuaded the government to kill every last bird on the island all 1.5 million of them. - the mass slaughter apparently worked the H5N1 virus disappeared from sight. - in 2001 another deadly H5N1 strain appeared in Hong Kong again, apparently coming into the territory from Southern China. - for the past 5 years, it has swapped genes with other avian-flu viruses to generate a large group of new H5N1 strains. - radiating from southern China, the virus spread to Japan, Indonesia and southern Asia by migrating waterfowl. - in summer 2006, the virus killed thousands of wild geese and gulls in western China. - it is spreading throughout the world having been found in western Europe (Turkey) and into Britain by an infected parrot. - it hasn t yet been identified in North America. - it may have already arrived from migratory waterfowl arriving from NE Asia. - however, the virus kills birds so quickly that it may not allow them to fly long distances. - according to the WHO, the H5N1 virus has killed 262 people since 2003, the majority being in Indonesia. - H5N1 spreads to all tissues in birds but in humans, like the 1918 flu, it attacks the lungs first. - estimates of the mortality caused by H5N1, if it successfully evolves human-to-human transmission, is 20 million (at the low end) to roughly 1 billion people. - the recently obtained complete sequence of the 1918 virus reveals that it did not result from reassortment, as did the 1957 and 1968 epidemics. - this adds to the concern that the H5N1 strain could adapt to humans in toto. The evolution of virulence - virulence is a measure of the harm done to a host by a pathogen during the course of infection. - a highly virulent pathogen has a major effect on its host (e.g., Ebola) whereas a pathogen with low virulence has a negligible effect on host fitness (e.g., some herpes viruses). - a classic example of the evolution of parasitic virulence involves the myxoma virus in populations of Australian rabbits. - rabbits have been an important pest species in Australia for well over a hundred years. - they were introduced to Australia in 1859 by a Mr. Thomas Austin who bought 12 rabbits from a company in England. - knowing what rabbits are known for, it is not surprising to hear how quickly they multiplied on Mr. Austin s farm.
6 - 6 years after they were introduced, it was estimated that 30,000 rabbits were present on his farm. - they escaped and exploded in abundance all over the country. - in an attempt to eradicate the epidemic, the Australian authorities introduced the myxoma virus into the country in the 1950 s in an attempt to bring down the rabbit population. - this virus causes the disease known as myxomatosis. - the virus was transmitted from rabbit to rabbit by means of mosquitoes. - because of the large population of biting insects down under, the disease spread quickly. - myxomatosis initially decimated the standing populations - reducing them by 99% in some regions. - the virus was extremely virulent when introduced into Australia. - in fact, it killed 100% of its hosts. - it wasn t too long, however, before its level of virulence began declining. - there were two factors involved in this response. - first, the virulence of the virus itself declined - this was demonstrated by infecting lab strains of rabbits with the virus sampled from natural populations over a number of years. - interestingly, the same virus was introduced into France in 1952 and surreptitiously into Britain in in both of these countries, the virus also declined quickly in virulence Virulence grade high low I II IIIa IIIb IV V Australia France Britain this example shows that reduced virulence can rapidly evolve. - myxoma virus that killed their hosts too quickly were not spread to new hosts as effectively (because mosquitoes do not bite dead rabbits). - therefore, viruses that allowed their hosts to survive longer enjoyed a higher fitness. - over time, no highly virulent forms of myxoma persisted in the wild. - why have pathogens evolved to be so variable in their level of virulence? - three models have been proposed to account for the evolution of virulence.
7 1. The coincidental evolution hypothesis - this proposes that the virulence of many pathogens in humans is not a direct target of selection. - rather, it is a result of selection acting on the pathogen in a different environment. - for example, tetanus is caused by a soil bacteria Clostridium tetani. - when this bacteria finds itself in a human wound it can rapidly grow in number. - the bacterium also produces a deadly toxin which makes such infections extremely dangerous. - since this bacterium does not normally live nor reproduce in humans the secretion of this toxin cannot be directed at humans but at something they encounter in their typical soil environment. 2. The short-sighted evolution hypothesis - pathogens commonly undergo many generations in a host before being able to infect a new host. - as a result, traits that increase the within-host fitness of the pathogen may actually be detrimental to the transmission of the pathogen to a new host. - hence, the virulence is short-sighted. - an example here is the poliovirus. - this virus normally infects cells that line the digestive tract and cause few symptoms. - occasionally, the virus infects cells of the nervous system. - this may increase the fitness of this lineage (because they face fewer competing strains) but are an evolutionary dead-end. 3. The trade-off hypothesis - the basis of this hypothesis is that a pathogen should evolve to a point in which its costs to the host are balanced by its capacity to propagate itself to other hosts. - therefore, pathogens may evolve to a point where they harm their hosts considerably. - the detriment caused to the host represents an optimal balance between harm to the host and benefit to the pathogen. - higher reproductive rates should benefit pathogens but if this reproductive rate is too fast, the harm done to the host could reduce pathogen fitness. - this idea was tested in a recent study by Messenger et al. (1999) involving the bacterium E. coli and a virus, the bacteriophage f1. - this phage can propagate both vertically and horizontally. - vertical transmission occurs when the host bacterium divides and the two daughter cells contain the phage. - horizontal transmission occurs when the phage moves to a new host. - Messenger et al. (1999) performed an experiment in which they restricted the transmission to being only vertical or only horizontal. - for the vertical transmission treatment, they simply prevented secreted virions from infecting new bacterial cells. - the only way the phage could propagate was through the reproduction of their hosts.
8 - for the horizontal transmission treatment, the researchers harvested secreted virions and introduced them to cultures of uninfected bacteria. - the only way virions could now spread was through secretion. - two sets of cultures were established: 1. 8 day long vertical transmission period followed by a brief horizontal phase day vertical phase with a brief horizontal phase. - the researchers made two predictions. 1. reduced virulence should evolve in the 8 day treatment. 2. phage reproductive rates should correlate negatively with host growth rates. - both predictions were met - phage strains that reduced their hosts growth rate most were those that reproduced more quickly in their hosts. - these findings are consistent with the trade-off hypothesis. - further support exists for the trade-off hypothesis in human pathogens. - first, vectorborne diseases tend to much virulent than diseases transmitted by direct contact. - this pattern is also found for bacteria that can be transmitted by infected water (like cholera) versus those that are transmitted by direct contact. Factors leading to increased virulence: 1. Live host not needed for transmission. - examples here include the ebola virus and some parasitic fungi (see fig !) 2. Multiple infections in a single host. - this leads to competition among pathogens within a host. - those that reproduce more rapidly (harming the host) would be favored. 3. Transmission is horizontal (i.e., from individual to individual) instead of vertical (i.e., from parent to offspring).
Lecture 19 Evolution and human health
Lecture 19 Evolution and human health The evolution of flu viruses The evolution of flu viruses Google Flu Trends data US data Check out: http://www.google.org/flutrends/ The evolution of flu viruses the
More informationLecture 18 Evolution and human health
Lecture 18 Evolution and human health Evolution and human health 1. Genetic factors 2. Infectious diseases Evolution and human health 1. Genetic factors Evolution and human health 1. Genetic factors P
More informationEvolution of influenza
Evolution of influenza Today: 1. Global health impact of flu - why should we care? 2. - what are the components of the virus and how do they change? 3. Where does influenza come from? - are there animal
More informationAn Evolutionary Story about HIV
An Evolutionary Story about HIV Charles Goodnight University of Vermont Based on Freeman and Herron Evolutionary Analysis The Aids Epidemic HIV has infected 60 million people. 1/3 have died so far Worst
More informationINFLUENZA-2 Avian Influenza
INFLUENZA-2 Avian Influenza VL 7 Dec. 9 th 2013 Mohammed El-Khateeb Overview 1. Background Information 2. Origin/History 3. Brief overview of genome structure 4. Geographical Distribution 5. Pandemic Nature
More informationInfluenza A virus subtype H5N1
Influenza A virus subtype H5N1 Influenza A virus subtype H5N1, also known as A(H5N1) or simply H5N1, is a subtype of the Influenza A virus which can cause illness in humans and many other animal species.
More informationOIE Situation Report for Highly Pathogenic Avian Influenza
OIE Situation Report for Highly Pathogenic Avian Influenza Latest update: 30/06/2018 The epidemiology of avian influenza (AI) is complex. The AI virus constantly evolves by mutation and re-assortment with
More informationWhere Health Care Meets Policy. with Dr. Mike Magee
Where Health Care Meets Policy with Dr. Mike Magee The Threat of Bird Flu Understanding Bird Flu and the Influenza Virus 3 types of the influenza virus: A, B and C reflect differences in the M protein
More informationOIE Situation Report for Highly Pathogenic Avian Influenza
OIE Situation Report for Highly Pathogenic Avian Influenza Latest update: 31/05/2018 The epidemiology of avian influenza (AI) is complex. The AI virus constantly evolves by mutation and re-assortment with
More informationAvian influenza Avian influenza ("bird flu") and the significance of its transmission to humans
15 January 2004 Avian influenza Avian influenza ("bird flu") and the significance of its transmission to humans The disease in birds: impact and control measures Avian influenza is an infectious disease
More informationAgricultural Outlook Forum Presented: February 16, 2006 THE CURRENT STATE OF SCIENCE ON AVIAN INFLUENZA
Agricultural Outlook Forum Presented: February 16, 2006 THE CURRENT STATE OF SCIENCE ON AVIAN INFLUENZA David L. Suarez Southeast Poultry Research Laboratory, Exotic and Emerging Avian Viral Diseases Research
More informationLESSON 4.5 WORKBOOK. How do viruses adapt Antigenic shift and drift and the flu pandemic
DEFINITIONS OF TERMS Gene a particular sequence of DNA or RNA that contains information for the synthesis of a protien or RNA molecule. For a complete list of defined terms, see the Glossary. LESSON 4.5
More information4/28/2013. The Ever-Evolving Flu p The 1918 Flu p. 617
The Ever-Evolving Flu p. 615 1. Influenza (Fig 18.10) rapidly evolves each year, and processes such as reassortment give rise to new genotypes. 2. Flu virus evolves rapidly to evade our immune system (Fig
More informationOIE Situation Report for Highly Pathogenic Avian Influenza
OIE Situation Report for Highly Pathogenic Avian Influenza Latest update: 28/02/2018 The epidemiology of avian influenza is complex. The virus constantly evolves and the behavior of each new subtype (and
More informationAvian influenza - current situation and future trends
Avian influenza - current situation and future trends Calogero Terregino OIE, FAO and National Reference Laboratory for Newcastle Disease and Avian Influenza, Istituto Zooprofilattico Sperimentale delle
More informationIntroduction to Avian Influenza
Introduction to Avian Influenza David L. Suarez D.V.M., Ph.D. Research Leader Exotic and Emerging Avian Viral Disease Research Unit Agricultural Research Service United States Department of Agriculture
More informationEarly Diagnosis: A Critical Step in Bird Flu Prevention
Early Diagnosis: A Critical Step in Bird Flu Prevention If avian influenza (bird flu) mutates sufficiently to jump from chickens and migratory birds to people, early diagnosis and identification of the
More informationAlphabet Soup of Flu Strains
1 of 6 16.03.2015 15:47 Author: Laurie Garrett, Senior Fellow for Global Health February 4, 2015 The year 2015 may be the most complicated influenza year in history. So many new types of flu, including
More informationInfluenza: The past, the present, the (future) pandemic
Influenza: The past, the present, the (future) pandemic Kristin Butler, MLS (ASCP) cm Department of Clinical Laboratory Sciences Louisiana Health Sciences Center - Shreveport Fall 2017 Objectives 1) Detail
More informationOIE Situation Report for Avian Influenza
OIE Situation Report for Avian Influenza Latest update: 25/01/2018 The epidemiology of avian influenza is complex. The virus constantly evolves and the behavior of each new subtype (and strains within
More informationEbola Virus. Emerging Diseases. Biosciences in the 21 st Century Dr. Amber Rice December 4, 2017
Ebola Virus Emerging Diseases Biosciences in the 21 st Century Dr. Amber Rice December 4, 2017 Outline Disease emergence: a case study How do pathogens shift hosts? Evolution within hosts: The evolution
More informationEmerging Diseases. Biosciences in the 21 st Century Dr. Amber Rice October 26, 2012
Emerging Diseases Biosciences in the 21 st Century Dr. Amber Rice October 26, 2012 Outline Disease emergence: a case study Introduction to phylogenetic trees Introduction to natural selection How do pathogens
More informationInfluenza: The Threat of a Pandemic
April, 2009 Definitions Epidemic: An increase in disease above what you what would normally expect. Pandemic: A worldwide epidemic 2 What is Influenza? Also called Flu, it is a contagious respiratory illness
More informationINFLUENZA A VIRUS. Structure of the influenza A virus particle.
INFLUENZA INFLUENZA A VIRUS Structure of the influenza A virus particle. TYPE A VIRUS HAS TWO TYPES OF SPIKES, THE HEMAGGLUTININ (H) AND THE NEURAMINIDASE (N), PROTRUDING FROM THE VIRAL ENVELOPE THE HEMAGGLUTININ
More informationAOHS Global Health. Unit 1, Lesson 3. Communicable Disease
AOHS Global Health Unit 1, Lesson 3 Communicable Disease Copyright 2012 2016 NAF. All rights reserved. A communicable disease is passed from one infected person to another The range of communicable diseases
More informationEpidemiology Treatment and control Sniffles and Sneezes Mortality Spanish flu Asian flu Hong Kong flu The Swine flu scare
Epidemiology Treatment and control Sniffles and Sneezes Mortality Spanish flu Asian flu Hong Kong flu The Swine flu scare Epidemiology The Flu Virus Influenza is commonly called the flu. The most deadly
More informationLecture 2 Evolution in action: the HIV virus
Lecture 2 Evolution in action: the HIV virus Peter and Rosemary Grant Barry Sinervo The HIV/AIDS pandemic Life expectancy in Botswana What is HIV? What is HIV? HIV is a retrovirus (i.e., RNA-based) with
More informationH5N1 avian influenza: timeline
H5N1 avian influenza: timeline 28 October 2005 Previous events in Asia 1996 Highly pathogenic H5N1 virus is isolated from a farmed goose in Guangdong Province, China. 1997 Outbreaks of highly pathogenic
More informationOverview: Chapter 19 Viruses: A Borrowed Life
Overview: Chapter 19 Viruses: A Borrowed Life Viruses called bacteriophages can infect and set in motion a genetic takeover of bacteria, such as Escherichia coli Viruses lead a kind of borrowed life between
More information2000 and Beyond: Confronting the Microbe Menace 1999 Holiday Lectures on Science Chapter List
2000 and Beyond: Confronting the Microbe Menace 1999 Holiday Lectures on Science Chapter List Lecture One Microbe Hunters: Tracking Infectious Agents Donald E. Ganem, M.D. 1. Start of Lecture One 2. Introduction
More informationPhylogenetic Methods
Phylogenetic Methods Multiple Sequence lignment Pairwise distance matrix lustering algorithms: NJ, UPM - guide trees Phylogenetic trees Nucleotide vs. amino acid sequences for phylogenies ) Nucleotides:
More informationInfluenza Viruses A Review
Influenza Viruses A Review AVIAN INFLUENZA: INTERSECTORAL COLLABORATION Larnaca, Cyprus 20 22 July 2009 Kate Glynn Scientific and Technical Department, OIE Influenza Viruses C. Goldsmith,1981 Influenza
More informationInfluenza surveillance and pandemic preparedness - a global challenge Anne Kelso
Influenza surveillance and pandemic preparedness - a global challenge Anne Kelso WHO Collaborating Centre for Reference and Research on Influenza Melbourne, Australia Three global health challenges 243
More informationUniversity of Colorado Denver. Pandemic Preparedness and Response Plan. April 30, 2009
University of Colorado Denver Pandemic Preparedness and Response Plan April 30, 2009 UCD Pandemic Preparedness and Response Plan Executive Summary The World Health Organization (WHO) and the Centers for
More information- Print, Podcast, Download MP3
Bi-Weekly Newsletter Vol. 4, No. 22 08 December 2006 - Introduction from Dr. David Evans, Smithsonian Under Secretary for Science - - - - Print, Podcast, Download MP3 Spotlight on Science at the Smithsonian
More informationPatterns of hemagglutinin evolution and the epidemiology of influenza
2 8 US Annual Mortality Rate All causes Infectious Disease Patterns of hemagglutinin evolution and the epidemiology of influenza DIMACS Working Group on Genetics and Evolution of Pathogens, 25 Nov 3 Deaths
More informationPandemic Influenza: Hype or Reality?
Pandemic Influenza: Hype or Reality? Leta Finch Executive Director, Higher Education Practice 2003 Arthur J. Gallagher & Co. Objectives Review key characteristics of influenza, including differences between
More informationPUBLIC HEALTH SIGNIFICANCE SEASONAL INFLUENZA AVIAN INFLUENZA SWINE INFLUENZA
INFLUENZA DEFINITION Influenza is an acute highly infectious viral disease characterized by fever, general and respiratory tract catarrhal manifestations. Influenza has 3 Types Seasonal Influenza Avian
More informationA secret about creationism
A secret about creationism Even among ardent creationists, most believe in evolution Why? Natural selection is a provable biological process. Selection causes evolution critical in medicine, agriculture
More informationInfluenza and the Poultry Link
Influenza and the Poultry Link Hemagglutinin Neuraminidase Type A Influenza Surface Antigens Subtype Surface Antigens Hemagglutinin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 human equine swine Neuraminidase
More informationJ. A. Sands, 21 October 2013 Lehigh University
J. A. Sands, 21 October 2013 Lehigh University Cryptococcus, Candidiasis, Aspergillosis Tuberculosis Cholera Plague Bact. Meningitis Salmonella Listeria Leptospirosis Staph. (MRSA) E. coli Clostridium
More informationAvian Influenza: Armageddon or Hype? Bryan E. Bledsoe, DO, FACEP The George Washington University Medical Center
Avian Influenza: Armageddon or Hype? Bryan E. Bledsoe, DO, FACEP The George Washington University Medical Center Definitions: Epidemic The occurrence of cases of an illness in a community or region which
More informationHS-LS4-4 Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
Unit 2, Lesson 2: Teacher s Edition 1 Unit 2: Lesson 2 Influenza and HIV Lesson Questions: o What steps are involved in viral infection and replication? o Why are some kinds of influenza virus more deadly
More informationSEA/CD/154 Distribution : General. Avian Influenza in South-East Asia Region: Priority Areas for Research
SEA/CD/154 Distribution : General Avian Influenza in South-East Asia Region: Priority Areas for Research World Health Organization Publications of the World Health Organization enjoy copyright protection
More informationVIROLOGY OF INFLUENZA. Subtypes: A - Causes outbreak B - Causes outbreaks C - Does not cause outbreaks
INFLUENZA VIROLOGY OF INFLUENZA Subtypes: A - Causes outbreak B - Causes outbreaks C - Does not cause outbreaks PATHOGENICITY High pathogenicity avian influenza (HPAI) Causes severe disease in poultry
More informationOIE Situation Report for Avian Influenza
OIE Situation Report for Avian Influenza Latest update: 24/04/2017 This report presents an overview of current disease events reported to the OIE by its Members. The objective is to describe what is happening
More informationBroadly protective influenza vaccines for pandemic preparedness. Suresh Mittal Department of Comparative Pathobiology Purdue University
Broadly protective influenza vaccines for pandemic preparedness Suresh Mittal Department of Comparative Pathobiology Purdue University Influenza A Virus Orthomyxovirus Consist of s/s (-) sense RNA 8 segments
More informationGlobal Catastrophic Biological Risks
Global Catastrophic Biological Risks Working Definition of Global Catastrophic Biological Risks (GCBRs) Events in which biological agents whether naturally emerging or reemerging, deliberately created
More informationAvian Influenza: Outbreak in Spring 2015 and Preparing for Fall
Avian Influenza: Outbreak in Spring 2015 and reparing for Fall James A. Roth, DVM, hd Center for Food Security and ublic Health College of Veterinary Medicine Iowa State University Topics for Today Understanding
More informationLesson 20 Study Guide: Medical Biotechnology Pandemic Flu & Emergent Disease
URI CMB 190 Issues in Biotechnology Lesson 20 Study Guide: Medical Biotechnology Pandemic Flu & Emergent Disease 1. The film Contagion: (A) entirely depicts a situation that could never possibly happen
More informationAVIAN FLU BACKGROUND ABOUT THE CAUSE. 2. Is this a form of SARS? No. SARS is caused by a Coronavirus, not an influenza virus.
AVIAN FLU BACKGROUND 1. What is Avian Influenza? Is there only one type of avian flu? Avian influenza, or "bird flu", is a contagious disease of animals caused by Type A flu viruses that normally infect
More informationDisease-causing organisms
1 of 41 2 of 41 Disease-causing organisms Organisms that cause disease are called pathogens. What are the four major types of pathogen? bacteria fungi protozoa virus 3 of 41 How do pathogens cause illness?
More informationAcute respiratory illness This is a disease that typically affects the airways in the nose and throat (the upper respiratory tract).
Influenza glossary Adapted from the Centers for Disease Control and Prevention, US https://www.cdc.gov/flu/glossary/index.htm and the World Health Organization http://www.wpro.who.int/emerging_diseases/glossary_rev_sept28.pdf?ua=1
More informationImmune System. Before You Read. Read to Learn
Immune System 37 section 1 Infectious Diseases Biology/Life Sciences 10.d Students know there are important differences between bacteria and viruses with respect to their requirements for growth and replication,
More informationRalph KY Lee Honorary Secretary HKIOEH
HKIOEH Round Table: Updates on Human Swine Influenza Facts and Strategies on Disease Control & Prevention in Occupational Hygiene Perspectives 9 July 2009 Ralph KY Lee Honorary Secretary HKIOEH 1 Influenza
More informationAvian Influenza (Bird Flu) Fact Sheet
What is an avian influenza A (H5N1) virus? Influenza A (H5N1) virus also called H5N1 virus is an influenza A virus subtype that occurs mainly in birds. It was first isolated from birds (terns) in South
More informationPandemic Influenza influenza epidemic: realization of a worst-case scenario
Pandemic Influenza October 9, 2006 1918 influenza epidemic: realization of a worst-case scenario First case: Albert Mitchell, Camp Funston, KS, March 11, 1918 Up to 20% of all humans infected 20-50 million
More informationAvian Influenza Virus H7N9. Dr. Di Liu Network Information Center Institute of Microbiology Chinese Academy of Sciences
Avian Influenza Virus H7N9 Dr. Di Liu Network Information Center Institute of Microbiology Chinese Academy of Sciences Avian Influenza Virus RNA virus, Orthomyxoviruses Influenza A virus Eight Gene segments
More informationEVOLUTION: WHY DOES IT MATTER? What did evolution ever do for me?
EVOLUTION: WHY DOES IT MATTER? What did evolution ever do for me? www.christs.cam.ac.uk/darwin200 Evolution is change in living things through descent with modification Evolution is change in living things
More informationerils of Manufactured Diseases ented by Christopher Bossert
erils of Manufactured Diseases ented by Christopher Bossert Introduction: Superbugs In 1928, penicillin was discovered the first true antibiotic. From then until now, we have steadily developed stronger
More informationInfluenza Infection In Human. Dr. Zuhaida A. Jalil Surveillance Sector Disease Control Division, MOH Malaysia 3 May 2018
Influenza Infection In Human Dr. Zuhaida A. Jalil Surveillance Sector Disease Control Division, MOH Malaysia 3 May 2018 Objective of the session: After completing this session, you will be able to: Understand
More informationDavid L. Suarez D.V.M., PhD. A.C.V.M.
David L. Suarez D.V.M., PhD. A.C.V.M. Southeast Poultry Research Laboratory United States National Poultry Research Center The author has no commercial interests in any commercial products presented. U.S.
More informationدکتر بهروز نقیلی استاد بیماریهای عفونی مرکس تحقیقات بیماریهای عفونی و گرمسیری پاییس 88
دکتر بهروز نقیلی استاد بیماریهای عفونی مرکس تحقیقات بیماریهای عفونی و گرمسیری پاییس 88 FLU.. How often can you escape? Three viral types are distinguished by their matrix and nucleoproteins Type Host Clinical
More informationBuy The Complete Version of This Book at Booklocker.com:
Amazing breakthrough remedy for swine flu from mother nature. How to Beat Swine Flu Naturally Buy The Complete Version of This Book at Booklocker.com: http://www.booklocker.com/p/books/4341.html?s=pdf
More informationOIE Situation Report for Avian Influenza
OIE Situation Report for Avian Influenza Latest update: 08/05/2017 This report presents an overview of current disease events reported to the OIE by its Members. The objective is to describe what is happening
More informationWhat is influenza virus? 13,000 base RNA genome: 1/ the size of the human genome
What is influenza virus? 13,000 base RNA genome: 1/246153 the size of the human genome CDC Principles of Virology, 4e Neumann et al. Nature. 2009. Influenza virus is one of the most deadly viral pathogens
More information7.013 Spring 2005 Problem Set 7
MI Department of Biology 7.013: Introductory Biology - Spring 2005 Instructors: Professor Hazel Sive, Professor yler Jacks, Dr. Claudette Gardel 7.013 Spring 2005 Problem Set 7 FRIDAY May 6th, 2005 Question
More informationWHY WE GET SICK THE EVOLUTIONARY ECOLOGY OF DISEASE
WHY WE GET SICK THE EVOLUTIONARY ECOLOGY OF DISEASE A FACT Medical science rarely employs an evolutionary perspective DEFINE DISEASE Abnormal or low performance SOMETHING TO REMEMBER Symptoms and causes
More informationPatricia Fitzgerald-Bocarsly
FLU Patricia Fitzgerald-Bocarsly October 23, 2008 Orthomyxoviruses Orthomyxo virus (ortho = true or correct ) Negative-sense RNA virus (complementary to mrna) Five different genera Influenza A, B, C Thogotovirus
More informationSegments 7 codes for M1 and M2 proteins (Matrix proteins)
One Flu over the Cuckoo s nest Dr Rachel Jones Department of Virology NPHS Microbiology Cardiff Whistlestop tour through Flu The virus Some history The Novel Virus Recent events The disease The control
More informationBiology 350: Microbial Diversity
Biology 350: Microbial Diversity Strange Invaders: Viruses, viroids, and prions. Lecture #27 7 November 2007-1- Notice handouts and announcements for today: Outline and study questions A 1999 paper discussing
More information1/29/2013. Viruses and Bacteria. Infectious Disease. Pathogens cause disease by: Chapters 16 and 17
Viruses and Bacteria Chapters 16 and 17 Infectious Disease Caused by the invasion of a host by agents whose activities harm the host s tissues Can be transmitted to others Pathogen microorganisms that
More informationEVOLUTION. Reading. Research in my Lab. Who am I? The Unifying Concept in Biology. Professor Carol Lee. On your Notecards please write the following:
Evolution 410 9/5/18 On your Notecards please write the following: EVOLUTION (1) Name (2) Year (3) Major (4) Courses taken in Biology (4) Career goals (5) Email address (6) Why am I taking this class?
More information11/15/2011. Outline. Structural Features and Characteristics. The Good the Bad and the Ugly. Viral Genomes. Structural Features and Characteristics
Chapter 19 - Viruses Outline I. Viruses A. Structure of viruses B. Common Characteristics of Viruses C. Viral replication D. HIV II. Prions The Good the Bad and the Ugly Viruses fit into the bad category
More informationLecture 2 The Darwinian Revolution
Lecture 2 The Darwinian Revolution Theories of evolution first developed by the Greek philosophers. Theories of evolution first developed by the Greek philosophers. Anaximander (610-546 BC) wrote about
More information19 Viruses BIOLOGY. Outline. Structural Features and Characteristics. The Good the Bad and the Ugly. Structural Features and Characteristics
9 Viruses CAMPBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman Minorsky Jackson Outline I. Viruses A. Structure of viruses B. Common Characteristics of Viruses C. Viral replication D. HIV Lecture Presentation
More informationLecture 11. Immunology and disease: parasite antigenic diversity
Lecture 11 Immunology and disease: parasite antigenic diversity RNAi interference video and tutorial (you are responsible for this material, so check it out.) http://www.pbs.org/wgbh/nova/sciencenow/3210/02.html
More informationGrade Level: Grades 9-12 Estimated Time Allotment Part 1: One 50- minute class period Part 2: One 50- minute class period
The History of Vaccines Lesson Plan: Viruses and Evolution Overview and Purpose: The purpose of this lesson is to prepare students for exploring the biological basis of vaccines. Students will explore
More informationLecture 2: Virology. I. Background
Lecture 2: Virology I. Background A. Properties 1. Simple biological systems a. Aggregates of nucleic acids and protein 2. Non-living a. Cannot reproduce or carry out metabolic activities outside of a
More informationInfluenza: Ecology and Continuing Evolution
Influenza: Ecology and Continuing Evolution Robert G. Webster, PhD Division of Virology Department of Infectious Diseases St. Jude Children s s Research Hospital Influenza Virus Negative sense RNA virus
More informationAdvances in Viral Immunity Stemming from the 1918 Flu Pandemic
Transcript Details This is a transcript of an educational program accessible on the ReachMD network. Details about the program and additional media formats for the program are accessible by visiting: https://reachmd.com/programs/clinicians-roundtable/advances-in-viral-immunity-stemming-from-the-
More informationCurrent Vaccines: Progress & Challenges. Influenza Vaccine what are the challenges?
Current Vaccines: Progress & Challenges Influenza Vaccine what are the challenges? Professor John S. Tam The Hong Kong Polytechnic University Asia-Pacific Alliance for the Control of Influenza (APACI)
More informationThe prokaryotic domains
Diversity of Bacteria, Archaea, and Viruses Chapter 19 The prokaryotic domains Bacteria Three types of structure Spherical, rod-shaped, and spiral Archaea Many are extremophilic Prefer to live in very
More informationDRAFT WGE WGE WGE WGE WGE WGE WGE WGE WGE WGE WGE WGE WGE WGE GETREADYNOWGE GETREADYNOWGE GETREADYNOWGE GETREADYNOWGE.
What Can I Do As A National Leader? This publication was produced by the AI.COMM project, managed by the Academy for Educational Development (AED), and funded by the U.S. Agency for International Development
More informationTopic 7 - Commonality
II. Organism Topic 7 - Commonality From Viruses to Bacteria to Genetic Engineering Prebiotic Period Refers to before life Early Earth contained little O 2 O 2 prevents complex molecules Complex organic
More informationOIE Situation Report for Avian Influenza
OIE Situation Report for Avian Influenza Latest update: 10/07/2017 This report presents an overview of current disease events reported to the OIE by its Members. The objective is to describe what is happening
More informationChapter 38 Viral Infections
Chapter 38 Viral Infections Primary Objectives of This Chapter Chapter 38 introduces a wide variety of important human viral diseases and serves as an introduction to Medical Virology. It is considered
More information2.1 VIRUSES. 2.1 Learning Goals
2.1 VIRUSES 2.1 Learning Goals To understand the structure, function, and how Viruses replicate To understand the difference between Viruses to Prokaryotes and Eukaryotes; namely that viruses are not classified
More informationHighly Pathogenic Avian Influenza Worldwide situation Larnaca, Cyprus, July 2009
Highly Pathogenic Avian Influenza Worldwide situation Larnaca, Cyprus, 20-22 July 2009 Dr Ghazi Yehia OIE Regional Representative for the Middle East HPAI Subtype H5N1: sequence of events 2003-2004: confined
More informationAP Biology. Viral diseases Polio. Chapter 18. Smallpox. Influenza: 1918 epidemic. Emerging viruses. A sense of size
Hepatitis Viral diseases Polio Chapter 18. Measles Viral Genetics Influenza: 1918 epidemic 30-40 million deaths world-wide Chicken pox Smallpox Eradicated in 1976 vaccinations ceased in 1980 at risk population?
More informationOutline. Origin and Biogeography of Human Infectious Disease. Advantages of virulence. Diseases differ in virulence. Serial passage experiments
Outline Origin and Biogeography of Human Infectious Disease Alan R. Rogers Evolution of virulence (Ewald 1983) Origin of human infectious diseases (Wolfe et al 2007). Biogeography of human infectious diseases
More information5/28/2015. Pregnancy, Birth and Postnatal for mother and baby. and Flu, oh my! An Update on Public Health Issues for Massage Therapists
World Massage Conference to support Presents: Pregnancy, Birth and Postnatal for mother and baby World Massage Conference Herpes and June Hep 2013 and Flu, oh my! An Update on Public Health Issues for
More informationChapter 19: The Genetics of Viruses and Bacteria
Chapter 19: The Genetics of Viruses and Bacteria What is Microbiology? Microbiology is the science that studies microorganisms = living things that are too small to be seen with the naked eye Microorganisms
More informationWhat we need to know about Bird Flu
AVIAN I NFLUENZA FACT S HEET What we need to know about Bird Flu 1. What is bird flu? How does it spread? Bird flu is primarily a disease of birds that live and feed in water, particularly ducks, geese,
More informationInfluenza. Paul K. S. Chan Department of Microbiology The Chinese University of Hong Kong
Influenza Paul K. S. Chan Department of Microbiology The Chinese University of Hong Kong Influenza Virus Nomenclature Influenza virus A, B & C Influenza A : Haemagglutinin (H), neuraminidase (N) A H3N2,
More informationPANDEMIC INFLUENZA PREPAREDNESS: STATE CHALLENGES
PANDEMIC INFLUENZA PREPAREDNESS: STATE CHALLENGES A Presentation to the Council of State Governments Health Policy Forum by Jeffrey Levi, Ph.D., Executive Director Trust for America s Health June 23, 2006
More informationInfluenza. By Allison Canestaro-Garcia. Disease Etiology:
Influenza By Allison Canestaro-Garcia Disease Etiology: The flu is an infectious disease caused by a subset of viruses of the family Orthomyxoviridae. There are 7 different viruses in this family, four
More informationInfluenza B viruses are not divided into subtypes, but can be further broken down into different strains.
Influenza General Information Influenza (the flu) is a highly transmissible respiratory illness caused by influenza viruses. It can cause mild to severe illness, and may lead to death. Older people, young
More informationObjective 3 Viruses & Bacteria genetic material capsule Pili DNA
Objective 3 Viruses & Bacteria 1. Compare the structure and functions of viruses to cells and describe the role of viruses in causing diseases and conditions such as acquired immune deficiency syndrome,
More informationInFLUenza. InFLUenza T W Z LEVELED READER W. Visit for thousands of books and materials.
InFLUenza A Reading A Z Level W Leveled Reader Word Count: 1,860 LEVELED READER W InFLUenza T W Z Written by Ned Jensen Visit www.readinga-z.com for thousands of books and materials. www.readinga-z.com
More information