How influenza can turn deadly

Although influenza – better known as flu – is a common illness that most people recover from without treatment, it can result in life-threatening or even deadly complications.

- Sarah Koh

On Feb 3, news broke that Taiwanese star Barbie Hsu, 48, had died, after she came down with influenza-related pneumonia during a holiday in Japan.

Here are some things to know about influenza viruses, symptoms and potential complications, and how you can protect yourself from them.

What are the different types of influenza viruses?

Influenza is a respiratory illness caused by influenza viruses. It is unlike a cold that is caused by a different group of viruses that attack the nose and throat, which can lead to inflammation and cause a blocked or runny nose, sneezing, watery eyes, sore throat and a cough.

According to the World Health Organisation (WHO), there are around one billion cases of seasonal influenza a year, with three to five million cases being classified as severe.

There are four types of influenza viruses: A, B, C and D.

The Ministry of Health’s (MOH) website states that the most common influenza viruses that spread in Singapore and globally are Influenza A (H1N1-2009), Influenza A (H3N2) and Influenza B.

Only Influenza A viruses have been known to cause pandemics, said WHO, while Influenza C viruses are not commonly detected and usually cause mild infections.

Influenza D viruses mainly affect cattle and are not known to spread to humans.