The document discusses swine flu, also known as H1N1 virus. It begins by defining swine flu and describing the three main types of influenza viruses: A, B, and C. It then provides details on the history and outbreak of H1N1 virus in 2009 in Mexico and the United States. The document concludes by describing the viral structure, genome, mode of action, symptoms, diagnosis, and treatment options for swine flu.

2. Swine flu
HAFSA ANWAR
SP14-BBI-B10-024

3. Outline
 What is swine flu
 Types of influenza virus
 History
 Viral structure
 Viral Genome
 Mode of Action
 Symptoms
 Diagnosis
 Drugs

4. Swine Flu
 Swine influenza virus (SIV) or swine-origin
influenza virus (S-OIV) is also known as the
H1N1 virus, is a relatively new strain of an
influenza virus that causes symptoms similar
to the regular flu. It originated in pigs, but is
spread primarily from person to person.

5. Types
There are three different types of influenza virus :
 Type A influenza virus (Most common and cause the most serious epidemics
multiple species)
 Type B influenza virus (can cause epidemics but disease is less severe, generally
infecting only in humans)
 Type C influenza virus (Not connected with epidemics more mild symptoms
infecting humans and swine)

6. History of H1N1
 Early 2009 in Mexico
 60 million Americans became infected
 265,000 Americans were hospitalized
 12,000 deaths occurred
 WHO issued it the 1st pandemic declaration of 21th century.

8. Structure
 Influenza virus has a rounded shape and
has a layer of spikes on the outside.
 There are two different kinds of spikes,
each made of a different proteins:
 Hemagglutinin (HA) protein
 Neuraminidase (NA) protein

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 The HA protein allows the virus to stick to a cell, so that it can enter into a host
cell and start the infection process.
 The NA protein is needed for the virus to exit the host cell, so that the new
viruses that were made inside the host cell can go on to infect more cells.

10. Subtypes or Strains
 There are 17 different versions of HA and 10 different versions of NA.
 A virus with version 1 of the HA protein and version 2 of the NA protein would be called
influenza A subtype H1N2 (A H1N2, for short).

11. Composition
 The new virus is named influenza A (H1N1), although it is commonly referred to
as swine flu. Although it is called swine flu.
 The new H1N1 virus is made up of a novel combination of segments from four
different influenza virus strains
 Eurasian swine virus,
 North American swine virus
 Avian influenza virus
 Human influenza virus

13. Mode of Action
 With the aid of envelope glycoprotein HA, influenza viruses can easily bind to
cell-surface glycosylated oligosaccharides that have sialic acids receptors at their
terminals, although this binding is very specific.
 HA helps the virus to attach to the sialic acid receptor of the host cell, which is
followed by endocytosis. Viral RNA polymerase transcribes the viral genome and
releases the mRNA for further processing.
 Mutations in the HA region of a virus may alter its binding affinity to the host.

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Hemagglutinin
Sialic Acid
Receptor
Endocytosis
Control over
host machinery
New copies of
virus

15. Symptoms
The symptoms of swine flu are very much like those of
regular influenza. They include:
 chills
 fever
 coughing
 sore throat
 runny nose
 body aches
 fatigue
 diarrhea
 vomiting

16. Diagnosis Methods
Travel history
Physical examination
Medical history
Nose and throat swabs (for laboratory analysis).

17. Drugs
zanamivir oseltamivir

18. Preventions
Frequent hand wash Get vaccinated Avoid sick pigs and sick
persons
Don’t travel the areas where
outbreak have occurred