This document provides information about influenza viruses with a focus on avian and swine flu. It defines influenza and describes the three main types - A, B, C. Type A is the most virulent and can cause pandemics, including bird flu (H5N1) and swine flu (H1N1). The document outlines the morphology, genome, transmission and symptoms of avian and swine flu viruses. It also discusses diagnosis, treatment and prevention for both types of influenza viruses.

1. MEDICAL
MICROBIOLOGY
ASSIGNMEN
T
M.Sc. Biotechnology 1st Semester
Topic: Influenza virus(Emphasis on Avian and Swine flu)
Submitted to: DR.Mairaj A. Ansari
Submitted by: Sana Saifi

2. What is INFLUENZA?
o Influenza, commonly called “ the flu,”is an illness caused by NEGATIVELY -SENSE SINGLE
STRANDED RNA VIRUSES of the family Orthomyxoviridae the influenza viruses that infect the
respiratory tract of many animals, birds and humans.
o Influenza is a highly contagious viral infection of
the nose,throat,and lungs that occurs most often
in the late fall,winter and early spring.
INFLUENZA VIRUSES ARE DIVIDED INTO THREE
TYPES:
 Influenza A
 Influenza B
 Influenza C
Influenza type A, B and C are similar in structure.Those are roughly
spherical of 80-120 nm in diameter but type-C may occur as filamentous.
 There are 25 serotypes of Influenza :16 HA and 9 NA varieties.
Influenza A: most virulent human pathogen among influenza viruses ,wide host-range,highest
serotypes;cause severe disease including:Bird-flu(H5N1),Swine-flu(H1N1),become pandemics.
Influenza B: mostly found in human and only two serotypes present.Influenza B don’t cause pandemics
due to limited host range.
Influenza C:It is similar and causes less severe disease.Don’t become endemic and no subtype present.

3. In June 2009, the World Health Organization declared the new strain of swine- origin H1N1 as a pandemic. This
strain is often called swine flu by the public media.this novel virus spread worldwide and had caused about
17,000 deaths by the start of 2010.On August 10, 2010,the World Heath Organization declared the H1N1
Influenza pandemic over ,saying worldwide flu activity had returned to typical seasonal patterns.
MORPHOLOGY:
 The outer layer is the lipid membrane,spikes are composed of
glycoproteins: Hemagglutanin(HA)and Neuraminidase(NA).
 There present M2 protein embedded in lipid membrane and M1
protein beneath the lipid membrane.
 The complete genome of Influenza is segmented into 8
fragments but 7 fragments in case of Influenza C.There
total 11 genes are located in the genome encoded 11
proteins.
 The genomic size is about 13.5bp
• HA and NA proteins determines the subtype of
influenza virus.
Pathophysiology
Influenza virus can infect both upper and lower
respiratory tracts. Sialic acid on epithelial cells are the
receptors.The typical incubation period of influenza is
24 hours to 4 days with average 2days.Childern’s are
more readily affected than adults.

4. AVIAN FLU
o Also called ‘Bird flu/influenza’is a viral infection that infect birds,caused by viruses adapted to birds.
o H5N1 is the most common form of bird flu.All known viruses that cause influenza in birds belong to the
species Influenza A virus
o Its deadly to birds and can easily affect humans and other animals that come in contact with the
carrier.
o Range of response from almost no signs of the disease to very high morality.
The incubation period is 3 to 7 days
Mode of transmission:
o Direct or indirect contact with infected live or dead poultry.
o No evidence –cooked food, No Human to Human transmission, But
mutation-Human to Human transmission
HOST: Usually chickens,ducks and turkeys.
ENVIROMENTAL:Usually winter ,Overcrowding
SYMPTOMS
 High grade fever>38 deg.C, Cough /sore throat
 Diarrhea,vomiting,abdominal pain,chest pain and bleeding from nose and gum.
 Complications; Hypoxemia,Multiple organ
dysfunction,Secondary bacterial and fungal infections.

5. Diagnosis:
o Nasopharyngeal aspirate/wash
o Nasopharyngeal/oropharyngeal/throat swab
o Paired serum
o Immuno fluorescent assay(IFA)
o Viral culture and RT-PCR
Treatment
o Oseltamivir-75mg BD for 5days
o After discharge-infection control precautions-7days
o Amantadine derivatives
Prevention and Control
 Early detection and managment
 Containment of transmission
 Decrease social disruption and economic loss
What if Human to Human transmission occurs?
 Avoid social gathering,If large geographical areas involved –
restriction of travel and trading.

6. SWINE FLU
o Swine flu is a respiratory disease caused by Type A influenza viruses that infect the respiratory tract of
pigs and infect the people ,typically those who have been in contact with pigs.(As of 2009 the known
SIV(Swine Influenza Virus) strains include influenza C and subtypes of influenza A known as
H1N1,H1N2,H3N1,H3N2,H2N3).The H1N1 is said to be a new strain of virus that is mostly a combination
of human influenza ,swine,and avian.
Mode of transmission:
 H1N1 virus can generally be spread through airborne of droplet transmission
 A person with swine flu can be contagious when he coughs,sneezes,or produce droplets that
may land on another person’s open surfaces,such as the eyes ,nose or mouth.
 Improper handling and cooking of pork products from swine infected with the H1N1 virus can also
be a way to get the illness.
SYMPTOMS
 The symptoms of swine flu in people are similar to the symptoms of regular human flu.
 Fever,cough ,sore throat ,body aches,runny nose,headache,chills and fatigue.
 Diarrhea and vomiting, but more manifested by children.
 Rare cases, progression to pneumonia and respiratory failure,leading to death.

7. Diagnosis:
 To swine influenza A infection,respiratory specimen would generally need to be collected within the first 4
to 5 days of illness .
 However,some persons,especially children,may shed virus for 10 days or longer.
 Identification as swine flu influenzaA
 Virus requires sending the specimen to a hospital laboratory for testing.
Treatment
 Oseltamivir(Tamiflu)or Zanamivir(Relenza) for the treatment and/or prevention of swine flu infection.
 Ayurvedic treatments: Septilin
 Some vaccines available like Squalene(Side effects:Autism)
Prevention and Control
 Follow precautions for seasonal influenza to control spread of disease.
 Vaccine approved by US FDA
 Wash hands regularly.
 Avoid contact with infected person,use a face mask.
 Keep yourself isolated from people with possible symptoms of flu;avoid visiting places with higher
possibility of transmission.

8. REFRENCES
:
 Centers for Disease Control and Prevention (CDC). 10 July 2019. Retrieved 24 January 2020.
 "Swine influenza". World Organisation for Animal Health. Retrieved 9 March 2021.
 https://en.wikipedia.org/wiki/Avian_influenza
 https://www.slideshare.net/piyoXD/influenza-12020504