Swine flu: Why some get it, others don't

It is well known that elderly, children and pregnant women are more vulnerable to swine flu but those who have died of the pandemic seem to have bucked the trend.

Some of them had no previous medical history and yet developed serious complications and were unable to recover. Is India following a different pattern?

Experts continue to maintain that the new H1N1 virus is a mild one yet seven people have died, and at least two of them with no history of any serious illness or chronic condition.

So, the big question: Who is more susceptible to the new virus?

"There is no data to show that the virus has turned virulent but from the deaths that have occurred across the world, the WHO is still trying to map the reasons why the virus causes severe infections in some and not in others," said Dr Randeep Guleria, Prof of Medicine, AIIMS.

"The death rates are very low - below 1%. In most cases, the virus is self-limiting. It is a new virus and scientists are grappling with it," Dr Guleria added.

The mutated human influenza virus emerged in April in Mexico and has spread to 168 countries. Though the virus has been sequenced fully enabling the manufacture of a vaccine, the data is still not comprehensive.

Doctors now say, the best way to prevent deaths is to watch out for the nine key swine flu symptoms and give tamiflu at the earliest.

They are:

• Fever, which is usually high, but unlike seasonal flu, 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

"There needs to be a change in policy. We now need hospital based surveillance. The containment stage is over, we need to give patients drugs as soon as he is suspected of swine flu. We need not wait for test results to begin treatment," Dr Guleria further said.

Time is vital in the management of swine flu and doctors say the earlier the medicines start for those with serious symptoms, the better the chances of beating the virus.