Swine flu: what is the H1N1 virus and how is it spread?

As India battles to contain one of its worst swine flu outbreaks, doctors urge people to protect themselves


India is currently struggling to contain its deadliest swine flu outbreak since 2010, with the infection killing more than 900 people so far. The H1N1 virus was responsible for a global pandemic in 2009, which originated in Mexico and the US. One in five people were infected, according to figures from 19 countries, and more than 200,000 people died worldwide.

What is swine flu and how is it spread?

Swine flu is an acute viral infection that originated in pigs. Flu viruses have the ability to mutate quickly, and pigs provide an excellent host for this. The H1N1 virus has developed the ability to spread among humans, who then infect each other through coughing and sneezing. It cannot be spread by eating pork or pork products.

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.


Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

Research from the University of Wisconsin suggests H1N1 is related to the 'Spanish flu' virus of 1918 that killed millions. The study suggests it penetrates deeper into the respiratory tissues - making it more likely to cause pneumonia. Blood tests show that people who lived through the 1918 flu pandemic would be immune to swine flu, but not to the seasonal flu that hits every year.

On the plus side, the H1N1 strain is far less dangerous than H5N1, or bird flu, and despite the similarities, it has not yet proven to be as severe as the 1918 virus.


The symptoms of swine flu are identical to normal seasonal flu symptoms: fever, coughing, sore throat, aching muscles, limb or joint pain, runny nose, lack of appetite and nausea. Some patients have also reported diarrhoea and vomiting. Those who have died suffered from pneumonia and respiratory failure.


During the global pandemic, a relatively small number of cases resulted in severe illness and death. The elderly, young children, pregnant women, or those with pre-existing illnesses are most likely to suffer complications from H1N1 as their immune systems are already weakened.

The death rate from the 2009 pandemic was just 0.02 per cent, according to research by scientists from the World Health Organization (WHO) and Imperial College London. Many healthcare experts argue that swine flu is no more dangerous than seasonal influenza.


"Good hygiene, such as hand washing and cleaning, is the most effective way of slowing the spread of flu," say doctors, as the virus can survive on surfaces such as door handles for up to 24 hours. Seasonal flu vaccines will also help prevent people from catching the virus and are available free on the NHS for those most at risk.


"The best remedy is to rest at home, keep warm and drink plenty of water to avoid dehydration," according to the NHS. Paracetamol or Ibuprofen can be taken to relieve aches and pains.

If complications occur, antiviral medications can be prescribed to help relieve symptoms and prevent more serious problems. Antibiotics may also be given to fight bacterial infections such as pneumonia.

Swine flu: Indian city bans public meetings as deaths soar

26 February

The Indian city of Ahmedabad has banned public gatherings in an attempt to halt the spread of swine flu, which has claimed more than 900 lives across the country in the deadliest outbreak since 2010.

More than 16,000 people in the states of Gujarat, Rajasthan, Maharashtra, Telangana and Madhya Pradesh have been infected with the H1N1 virus since December. Both the Gujarat state assembly's speaker and health minister have swine flu, according to the BBC.

The disease continues to spread rapidly, with the total number of cases doubling since 11 February. However, doctors predict that the outbreak will subside as temperatures begin to rise in the summer months. Low temperatures have been blamed for the increase in H1N1 infections.

"One of the reasons could be that the traditionally tropical state [of Telangana] has experienced its coldest winter in two decades with temperatures dipping to single digits," L Narendranath, chief of the state-run Nizam's Institute of Medical Sciences told the BBC.

Despite the ban on public gatherings, health officials in Ahmedabad have urged the public not to panic, insisting that there is enough medication to cope with the increase in infections.

However, private chemists have reported shortages, due to customers "rushing to stockpile supplies".

Private companies have also attempted to cash in on the outbreak. "Diagnostic testing services in some cities have been quick to profit on the mass panic by inflating test prices," reports Bloomberg.

In response, the government capped the price of the diagnostic test at 4,500 rupees (£46) and is providing free tests at specified government hospitals.

Despite this, the government is facing widespread criticism of its handling of the outbreak, with India's National Congress accusing the country's prime minister Narendra Modi of responding to the public health crisis in a "casual manner", according to the Indian Express.

To continue reading this article...
Continue reading this article and get limited website access each month.
Get unlimited website access, exclusive newsletters plus much more.
Cancel or pause at any time.
Already a subscriber to The Week?
Not sure which email you used for your subscription? Contact us