Tentative Table of Contents

Deadly Diseases and Epidemics

Influenza

 

1. History of the Disease - Deadly World Traveler

2. Causes of the Disease

3. Signs and Symptoms of the Season

4. Constant Change and Dispersal Mechanisms

5. Diagnostic Techniques

6. Treatment

7. Prevention

8. Immunity, Complications and Implications

 

 

 

Expanded Versions of Tentative Chapters Appended

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Chapter I History

1. The Early Years
   1. Where did it come from?
   2. The spread from Europe to North America
   3. Potential political impact on U.S.
2. Colonial Expansion
   1. The War Years
   2. Death by the millions
3. Post War Discoveries
   1. New Threats - 1957, 1968
   2. What Does the Future Hold?

-----------------------------------------------------------------------------------------------------------

Chapter II Causes

1. What Is a Virus?
   1. Quick History
   2. Current Understanding - Intracellular Genetic Parasite
2. Characteristics
   1. Genetic Information
      1. DNA - single or double-stranded (s or d)
      2. RNA - single or double-stranded (s or d)
   2. Protective covering - mainly protein - called "capsid"
   3. Some have additional covering known as "envelope"
3. Total collective structure called a "virion"
4. How Do Flu Viruses Replicate?
   1. Attachment to host cell
      1. Receptor -binding protein of virus
      2. Binds to specific receptors on certain cells' surfaces
   2. Internalization - taken inside host cell
      1. Receptor mediated endocytosis
   3. Take over genetic information of host
      1. host produces capsid proteins and copies genetic info
      2. host produces necessary enzymes and assembles new viruses
   4. Viruses leave cells either by budding or destruction of cell
5. Other viruses have minor variations on these basic themes
6. Viral Group for Influenza - Orthomyxoviruses
   1. Type A - isolated from patient in 1933
   2. Type B - 1940
   3. Type C - 1949
7. Structure of Flu Virion
   1. +/- 500 protein spikes sticking out of envelope - apparently aid in getting into and out of cell and attachment
      1. =/- 80% are hemagglutinin (HA) - causes RBC's to clump together - serves as flu receptor binding protein
      2. +/- 20% neuraminidase (NA) - serves as enzyme that influences release of newly formed virions
      3. together they are responsible for viral pathogenicity and virulence (ability to cause disease and degree of severity)
   2. To date 14 different version (antigenic subtypes) of HA (H1-H14) and 9 different versions of NA (N1-N9) have been identified
8. Changes in the combinations of these 2 proteins lead to different pathogenic strains of the viruses each year
   1. All subtypes are found in waterfowl; some are found in humans (H1N1, H2N2, H3N3, H1N2, H1N3, etc.), swine and horses
   2. Type B does not show such subtypes

------------------------------------------------------------------------------------------------------------

Chapter III "Tis the Season" - The Signs and Symptoms

1. North-South Hemispheric Differences
2. How Influenza Develops
3. The Clinical Course
   1. How do you know it's the flu and not a cold
   2. Comparison chart showing symptoms
   3. Common Symptoms
      1. 1-4 days after exposure
      2. some symptoms caused by body's response to virus
      3. some symptoms disappear and are replaced with others
      4. occasional complications

------------------------------------------------------------------------------------------------------------

Chapter IV Constantly Changing - The Greek God Proteus

1. Types of Influenza
   1. Occurrence
   2. Structural Differences - Different Effects
2. Changes Over Time
   1. Antigenic Drift - slow change due to progressive accumulation of individual mutations
   2. Antigenic Shift - more rapid shift in type
   3. Gene Swapping or Reassortment in Type A - cell infected with two different strains of type A
3. Chart of Past Pandemics and Associated Types
4. New Evidence to show that the Pandemic of 1918 was due to a Recombinant Strain rather than a reassorted one
5. The Role of Ducks and Pigs in new strains of flu

------------------------------------------------------------------------------------------------------------

Chapter V Diagnosis

1. Generally done by symptoms alone when there is an epidemic in the community
   1. Problem - lots of diseases (viral and nonviral) have flu-like symptoms
   2. Lab Tests - vary in length of time required to provide results
   1. Rapid tests in office - less than 30 minutes
   2. longer tests take days to weeks
   3. reliability and sensitivity vary considerably
2. Detection Methods
   1. Viral structure - electron microscopy
   2. viral antigen - immunofluorescence
   3. effect of virus - cytopathic effect on cells
   4. viral nucleic acid - PCR
   5. anti-viral antibodies - ELISA test
3. A Word about Antiviral Immunity
   1. Role of Interferon
   2. Other immune system components involved

------------------------------------------------------------------------------------------------------------

Chapter VI Treatment "I've got the flu. What shall I do?"

1. Be Sure it's really influenza
   1. Stomach flu or Gastroenteritis
   2. Colds or Strep throat
2. What To Do
   1. Surprise - Stay Home and get Bed Rest
   2. Lots of Liquids
   3. Over the counter medication to relieve symptoms
3. Avoidance
   1. Crowds - Schools, Malls, Churches
   2. Wash hands frequently
   3. Use tissues for sneezes and coughs
4. Treatment Regimes
   1. Prescription Medication for Prevention or to Moderate the Course of the Disease
      1. Inhaled Treatment - Relenza (zanamivir) - reduces severity - cuts by 1-2 days
      2. Tablet - Tamiflu (oseltamivir) - adults and children over 13 usually
      3. Synmetrel, Lysovir (amantidine) - works on A only
      4. Flumadine (rimantadine) - both c & d can be used by adults and children over age 1 but there are side effects
   2. Call Doctor if consciousness becomes altered or clouded or if you become breathless
   3. For all other common symptoms use home care remedies

------------------------------------------------------------------------------------------------------------

Chapter VII Prevention

1. Avoidance
2. Medications
3. Vaccination - Guidelines
   1. Who should get the shot - High Risk or Target groups
      1. any 6 months 7 older
      2. all 50 +
      3. persons with certain chronic medical conditions
      4. health care workers
      5. household members of high risk persons
      6. certain travelers
      7. students or those in close living quarters
      8. pregnant in 2nd or 3rd trimester
4. Why a new vaccine every year
   1. How are vaccines made
   2. Sources- Types of Vaccines
      1. Live Virus Vaccines
      2. Cold-Adapted Live Virus Vaccines
      3. Vaccines from Avian/Human Strains of Flu Virus
      4. Nasal flu Vaccines
5. Role of WHO
   1. Sentinel Surveillance for Influenza

------------------------------------------------------------------------------------------------------------

Chapter VIII Complications

1. Bacterial and other viral complications - Symptoms of complications may appear after a brief improvement
   1. Kids
      1. otitis media
      2. croup
      3. convulsions due to fever
   2. Others
      1. bronchitis
      2. pneumonia
   3. may have high fever, shaking chills, chest pain while breathing, cough with thick yellow-green mucous
   4. Reye's syndrome in children & adolescents on asprin treatment (fewer than 3/100,000)
2. Side Effects of Drugs
   1. difficulty sleeping, trembling, depression, G-I upset
   2. Asthma may get worse with one drug
3. Reactions to Vaccine
   1. site reaction - swollen, red, tender
   2. children may have fever after 24 hours, chills or headache or sick feeling
   3. allergic reaction to egg protein - viruses are grown in hens eggs
   4. Existing respiratory problems may get worse temporarily
   5. Guillain-Barre Syndrome (rare paralytic disorder)
4. Antiviral Immunity