Home > Living > Emergency planning > Pandemic flu

Pandemic flu

What is pandemic flu?
Flu that spreads rapidly causing widespread epidemics around the world. Pandemic flu occurs when a new, highly infectious and dangerous strain of the influenza virus appears. In contrast to the ‘ordinary’ or ‘seasonal’ flu outbreaks which we see every winter in the UK, flu pandemics occur infrequently- usually every few decades. There were three last century. The most serious was in 1918, killing millions of people worldwide. Smaller pandemics happened in 1957 and 1968.

What is the difference between seasonal, avian and pandemic flu?
It is important to be clear about the differences between seasonal flu, avian flu and pandemic flu. Avian flu is a disease which mainly affects birds. Seasonal flu refers to the viruses that circulate in the human population and cause widespread illness each winter. Pandemic flu occurs infrequently, when a new influenza virus emerges which is markedly different from those recently circulating in the human population, causes disease in people and spreads easily between people because they have little or no immunity to it. This could happen through an avian flu virus (such as H5N1) mutating into a different strain with greater affinity for people.

Are we at risk right now?
A pandemic can start when three conditions have been met:

1. a new influenza virus subtype emerges;
2. it infects humans, causing serious illness; and
3. it spreads easily and sustainably among humans.

The H5N1 virus meets the first two conditions and it is likely that nobody will have immunity should an H5N1-like pandemic virus emerge. The H5N1 virus has not yet demonstrated the ability to pass easily between people. However, the virus is currently passing from birds to humans so it could develop the ability to pass easily between people. These opportunities will also persist as long as the virus continues to circulate in birds.

Is another influenza pandemic likely?
Flu viruses are constantly changing and adapting, so it is likely that viruses sufficiently different from ‘ordinary’ flu strains to cause a pandemic will emerge from time to time. International disease experts are saying that the world is overdue for the next pandemic. Experts are particularly concerned that the H5N1 virus, which has already caused disease and death in humans, may develop the capacity to pass easily between people.

How is the virus spread?
The virus is passed from person to person by breathing in air containing the virus produced when an infected person talks, coughs or sneezes. It can also be spread through hand/face contact after touching a person or surface contaminated with the virus.

Can it be prevented at any stage?
International effort will attempt to try to control a pandemic when it emerges. The World Health Organization has stockpiled supplies of antivirals which will be targeted to the infected area in order to try to slow or stop the spread.

What are the symptoms of pandemic flu?
People infected with the current strand of the avian virus (H5N1) have shown everything from typical human influenza-like symptoms (fever, cough, sore throat, and muscle aches) to pneumonia, severe respiratory diseases, and other life-threatening complications. Symptoms of avian influenza may depend on which specific virus subtype and strain caused the infection.

How are people treated?
Medicines called antivirals can be used to treat influenza They have been shown to be very helpful in the treatment of 'ordinary' flu, and it is likely that they will also be effective in the treatment of pandemic flu, but their effectiveness will not be known until the pandemic virus is circulating. Antivirals do not stop the flu from developing but they do subdue the symptoms and reduce the length of time people are sick.

More questions are answered on the Department of Health website, linked to on the right of this page.

---