What is Swine Flu.......?
- The Common (the usual human) Flu is a common cold like disease caused by influenza virus A or influenza virus B.
- This virus has many strains which affect a specify group of animals or birds.
- The human influenza virus affects humans
- There are also strains of the virus which infect specifically birds and pigs (respvtly. called the bird flu virus or the swine flu virus)
Origin of swine flu:
- This is what happened to create the swine flu virus
- A pig was infected with both human influenza virus & swine influenza virus.
- An exchange of genetic materials took place in the body of the pig among the 2 strains
- This is an new strain of virus (the virus which is causing the swine flu right now)
- This virus retained its ability to infect humans and spreads to humans from humans only.
- This virus lost its ability to multiply in pigs and doesn’t infect pigs and doesn’t spread from pigs to human beings or amongst pigs.
- So pig is not a reservoir for human infection and hence no need to kill or treat or isolate pigs.
- This virus is called swine flu virus(technically the human swine recombinant influenza virus)
- This is not the case with Bird flu virus which has a similar origin in birds. The bird flu virus infects only birds and spreads only amongst birds and doesn’t affect humans. Read More...
Why is this 'swine flu' a big problem?
- The Common (the usual human) Flu is a common infection. It is not a big problem.
- It affects humans and runs its usual course for a week or so, with main symptoms as cough, cold, fever and body pain.
- There is no need to treat this infection if the individual is perfectly healthy otherwise. In a patient with heart disease or other chronic illness, this infection may be fatal and hence the need for vaccination or treatment with drugs like Amantidine and Rimantidine.
- Since this virus is an old virus(though it has great ability to mutate), humans have developed considerable immunity and have adequate antibodies to fight off the infection.
- Now considering the swine virus, since this is a new strain of virus, the human population is not immune to this virus and so it can infect any one.
- After this infection, a normal person without any serious disease would develop immunity.
- But in a person with pre existing severe disease or in a child, this infection may be fatal because there is no vaccine and no effective drug as of yet.
- Major pharmaceutical companies are trying to develop a vaccine. But it will take a lot of time to develop the vaccine. By the time the vaccine comes to market the infection would have spread to most people and then the vaccine will be unnecessary. The vaccine prepared would go only to waste. It may help protect those high risk patients (those with pre existing severe disease) from this infection.
- Oseltamivir (Tamiflu)
Dose 75mg oral tablet, twice daily for 5 days.
- Zanamivir(oral spray)
- These drugs reduce the duration of disease by one day.
- The effectiveness of these drugs is studied only in otherwise healthy persons and not in patients with serious disease.
- For patients with pre existing severe disease and in children, with swine flu virus infection, supportive management is all we can do. This includes airway management, control of concurrent infection & maintenance of hydration and nutrition.