Swine Flu Pandemic : It’s Influenza again

Swine flu:

Swine Influenza also known as H1N1 flu, Swine flu, Pig and Hog flu is a virus commonly found in pigs throughout the world.



Causative agent:-

  • Most commonly, swine influenza is of the H1N1 influenza subtype.
  • other types:- H1N2, H3N1, and H3N2.
  • Its official name or scientific name is H1N1 influenza A. The H means hemagglutinin and the N means neuraminidase and the 1s refer to their antibody type.
  • Influenza A is a genus of the Orthomyxoviridae family of viruses
  • The current outbreak ( 2009) of swine flu that has infected humans is of the H1N1 type, this type is not as dangerous as some others. It is caused by a new virus that has changed in ways that allow it to spread from person to person and its happening among people who haven’t had any contact with pigs.
  • This virus has components of pig and bird viruses in it, and humans don’t have any immunity to it. That is what has made it more likely to become a pandemic virus (that can cause a global outbreak) as it could easily spread from human to human.
  • H1N1 is the same strain which causes seasonal outbreaks of flu in humans on regular basis. But latest version of H1N1 is different: it contains genetic material that is typically found in strains of the virus that affect humans, birds and swine.

  • Flu viruses have the ability to swap genetic components with other, and it seems likely that the new version of H1N1 resulted from a mixing of different versions of the virus, which may usually affect different species, in the same animal host.
  • Pigs provide an excellent melting pot for these viruses to mix and match with each others.


  • Influenza is mainly passed from person to person through droplet transmission. This occurs when a sick person coughs or sneezes contaminated droplets into the air, and a healthy person either inhales them or gets them on their hands and then later transfers them to their mouth, nose or eyes.
  • People with H1N1 are likely contagious for one day before and up to seven days after they began to get sick with swine flu symptoms.
  • Good respiratory hygiene can help prevent illness from spreading. Everyone should practice good respiratory hygiene, even if they do not appear sick, since people can pass on the flu before they even show symptoms.
India has swine flu

India has swine flu

Who are at greater risk?

  • Pregnant women.
  • Young children.
  • Age of 65 years or older.
  • People with Chronic health problems (such as asthma, diabetes, heart disease, diabetes,and  immunosuppression . )


  • fever, which is usually high, but unlike seasonal influenza, is sometimes absent.
  • cough.
  • runny nose or stuffy nose.
  • sore throat.
  • body aches.
  • headache.
  • chills.
  • fatigue or tiredness, which can be extreme.
  • diarrhea and vomiting, sometimes, but more commonly seen than with seasonal flu.

Diagonosis of Swine Flu (H1N1)

Swine influenza A infection is diagnosed when an infected person is most likely to be shedding virus i.e, within the first four to five days of illness (children may shed virus for ten days or longer) during this period respiratory specimens are collected and sent for diagnosis to the state labs.

This is diagnosed clinically by the patient’s history of exposure to people having swine flu and also based upon their symptoms.

A quick test (for example, nasopharyngeal swab sample) is done to see if the patient is infected with influenza A or B virus. Most of the tests can distinguish between A and B types. The test can be negative (no H1N1 infection) or positive for type A and B. If the test is positive for type B, the flu is not likely to be swine influenza (H1N1). If it is positive for type A, the person could have a conventional influenza strain or swine influenza (H1N1).

H1N1 is mainly diagnosed by identifying the particular antigens associated with the virus type. This test is done in a specialized laboratory and is not done by many doctors clinics or hospital laboratories.


Suspected Cases.

1.Empiric antiviral treatment is recommended for any ill person suspected to have swine influenza A (H1N1) virus infection.

2.Antiviral treatment with either zanamivir alone or with a combination of oseltamivir and either amantadine or rimantadine should be initiated as soon as possible after the onset of symptoms.

3.Recommended duration of treatment is five days.

4.Antiviral doses and schedules recommended for treatment of swine influenza A (H1N1) virus infection are the same as those recommended for seasonal influenza.

Confirmed Cases

1.For antiviral treatment of a confirmed case of swine influenza A (H1N1) virus infection, either oseltamivir (Tamiflu) or zanamivir (Relenza) may be administered.

2.Recommended duration of treatment is five days.

3.These same antivirals should be considered for treatment of cases that test positive for influenza A but test negative for seasonal influenza viruses H3 and H1 by PCR.

Measures and Preventions

  • Practice good hygiene.

Hand Washing is a vital practice to avoid the spread of the flu.

Wash for at least 10-20 seconds:

After coughing or sneezing

After touching animals or animal waste

Prior to eating

After using bathroom

Before during and after food preparation

After touching the nose or mouth

After changing diapers/ nappies

Whenever hands are dirty

After touching your shoes

During pandemic, also wash after touching shared objects (phone, desks, etc )

  • Use a tissue when you cough or sneeze.
  • Stay away from others when you are sick.
  • Developing good hygiene habits now could help in the event of influenza pandemics.
  • Be ready for an emergency.
    • Store a two-week supply of water and food.
    • Have prescription and nonprescription drugs and other health supplies on hand, including pain relievers and cold medicines.

How Swine flu infection be controlled at home and public places?

swine flu prevent


Infection Control at home.

1.Separation from others in single room if available.

2.The ill person should wear a mask.

3. Remind the sick person to cover their coughs, and clean their hands with soap and water or an alcohol-based hand rub often, especially after coughing and/or sneezing.

4.Utensils used by the ill person should be thoroughly washed with soap and water before use by other persons.

Infection Control at public places

1.Cover you mouth and nose when you cough or sneeze

2.Throwing used tissues and towels into the garbage or laundry

3.Staying home if you are unfortunate to contract the Swine Flu Virus

4.public areas need to be kept cleaned and virus free because these are the places that the public spends most of their day. Children are at school.

Emergency Medical Care

When to Seek Emergency Medical Care ?

Get medicalcare right away for the sick person at home:

1. If he/she has difficulty breathing or chest pain.

2. The person has purple or blue discoloration of the lips.

3. If the infected person is vomiting and unable to keep liquids down.

4. If he/she has signs of dehydration such as dizziness when standing, absence of urination.

5. Infants have lack of tears when they cry.

6. The infected person is less responsive than normal or becomes confused.

This virus is antigenically very different from human H1N1 viruses and, therefore, vaccines for human seasonal influenza would not provide protection from it.



Article By : Dr. Saurav Shrestha

  1. December 9, 2009
  2. June 25, 2010

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