Dr. SURAJ PGT-BIOLOGY

History • Swine influenza also called as pig influenza, swine

flu, hog flu and pig flu.

• Swine influenza virus is common throughout pig

populations worldwide. Generally transmission of

the virus from pigs to humans is not common.

• Swine influenza was first proposed to be a

disease related to human flu during the 1918 flu

pandemic, when pigs became ill at the same time

as humans.

• Around 1918, the ancestral virus, of avian

origin, crossed the species boundaries and

infected humans as human H1N1.

• The first identification of an influenza virus as

a cause of disease in pigs occurred about ten

years later in 1930.

• Until 1968, when the avian strain H1N1

infected humans again; this time the virus met

the strain H2N2, and the reassortment

originated the strain H3N2.

• Then, between 1997 and 2002, new strains of

three different subtypes and five different

genotypes emerged.

• On June 11, 2009, the World Health

Organization raised the worldwide pandemic

alert level to Phase 6 for swine flu, which is

the highest alert level.

Types of Swine flu virus

• H1N1 (Hemagglutinin 1 Neuraminidase 1 )

• H1N2

• H3N2

• H3N4

• H4N6

Stage of H1N1 virus infection

World wide condition of Swine flu

(H1N1)

Status of Swine flu in India

• In 2015 the instances of Swine Flu

substantially increased to five year highs with

over 10,000 cases reported and 660 deaths in

India.

• The states reporting the highest number of

cases and deaths are Rajasthan, Gujarat,

Madhya Pradesh, Maharashtra, Delhi, and

Telengana.

Structure of H1N1 virus

• The influenza virion is roughly spherical. It is an enveloped virus.

• The outer layer is a lipid membrane (taken from host cell).

• Lipid membrane are spikes , which are proteins – actually glycoproteins, because they consist of protein linked to sugars – known as HA (hemagglutinin) and NA (neuraminidase). These are the proteins that determine the subtype of influenza virus (A/H1N1)

Transmission

• Transmission between pigs

• Influenza is quite common in pigs, with about half of breeding pigs having been exposed to the virus in India.

• The main route of transmission is through direct contact between infected and uninfected animals.

• Airborne transmission through the aerosols produced by pigs coughing or sneezing are also an important means of infection.

Transmission to

humans

• People who work with poultry and swine, especially those

with intense exposures, are at increased risk of infection.

• Influenza spreads between humans when infected people

cough or sneeze, then other people breathe in the virus or

touch something with the virus on it and then touch their

own face."Avoid touching your eyes, nose or mouth.

Life cycle of swine flu virus

Signs and symptoms

In swine

• In pigs, influenza infection produces fever,

lethargy, sneezing, coughing, difficulty

breathing and decreased appetite.

• In some cases the infection can cause

abortion.

• The virus can produce weight loss and poor

growth.

In humans

• Direct transmission of a swine flu virus from

pigs to humans is occasionally possible.

• Symptoms include fever, cough, sore throat,

body aches, headache, chills and fatigue. The

2009, outbreak has shown an increased

percentage of patients reporting diarrhea and

vomiting.

Prevention • Avoid close contacts.

• Stay home when you are sick.

• Cover your mouth and nose with a tissue while coughing or sneezing.

• Avoid touching your mouth, eye and nose.

• frequent washing of hands with soap and water or sanitizers, especially after being out in public.

• Practice other good health habits.

• Stay at least 6 feet away from people with flu-like illness.

Tests for Swine Flu

• To test for swine flu, your doctor takes a

sample from your nose or throat.

• Centers for Disease Control and Prevention

(CDC) recommends real time PCR as the

method of choice for diagnosing H1N1.

• The oral or nasal fluid collection and RNA virus

preserving filter paper card is commercially

available.

Treatment

• In swine flu, antiviral drugs can make the illness milder and make the patient feel better faster.

• Beside antivirals, supportive care at home or in a hospital focuses on controlling fevers, relieving pain and maintaining fluid balance, as well as identifying and treating any secondary infections or other medical problems.

• Some of the same antiviral drugs that are used to treat seasonal flu also work against H1N1 swine flu. Oseltamivir (Tamiflu) and zanamivir (Relenza) seem to work best, although some kinds of swine flu are resistant to Tamiflu.

Tamiflu and Relenza

• These drugs can help you get over swine flu

faster. They can also help keep it from being

too severe. They work best when taken within

48 hours of the first flu symptoms, but they

can help when taken later.

• Antibiotics won't help, because flu is caused

by a virus, not bacteria.

• People with regular exposure to pigs are at

increased risk of swine flu infection.

• In August 2010, the World Health Organization

declared the swine flu pandemic officially over

The Differences Between Seasonal Flu

and Swine Flu

• In seasonal flue, symptoms include fever,

cough, sore throat, stuffy or runny nose, body

aches, headache, chills and fatigue.

• Swine flu patients also report diarrhea and

vomiting, not usually present in seasonal flu.

Myths about swine flu

1. I am healthy, I do not need to worry.

2. I am immune because I've had it.

3. Vaccine guarantees protection.

4. The vaccine can give you the flu.

5. Antibiotics can help.

6. If I feel okay, I am not infectious.

Frequently asked questions..

• Can I have the flu by eating pork and chicken?

• Is it OK to kiss someone on the cheek or lips?

• Is it safe to shake hands?

• Should I wear a face mask?

• How do I know if I have swine flu or just some

other cold or virus?

• Should people avoid traveling now?