'Flu is a serious disease which causes widespread illness each year throughout the UK. (1) It is a viral infection that is usually seen during the winter months. A 'flu outbreak usually lasts for 6-8 weeks across the country.

Everyone is at risk of contracting ‘flu.

'Flu spreads by droplets in the air (by coughing, for example) gaining entry to our bodies through our noses, mouths and eyes. It is also spread by touch but to a lesser extent. Once inside the body, the virus multiplies rapidly to produce millions of virus particles.

The most common type of 'flu is influenza A. This virus usually changes slightly every year, so even if you were unlucky enough to have flu last year you may not have a full immunity for this year.

Work performance is reduced for several days after a bout of the 'flu. (2)

Population attack rates can vary between 5-10% in a normal season and up to 40% in major epidemics and pandemics. (3)

During the winter of 1999/2000 there were more than 16,000 excess deaths in England and Wales attributable to influenza. (4)

Epidemics have occurred every 1-3 years. (1) But the last epidemic in England was four seasons ago in 1999/2000.

Pandemics have occurred every 11-42 years. (5)

The 1918 pandemic killed 40 million people; more people than died in fighting in the First World War.

It is impossible to forecast in advance whether 'flu will strike in its mildest or most severe pandemic form.

The impact of ‘flu on productivity in a working population and the resultant cost to employers and employees is considerable.

The Consumer Health Information Centre estimates that more than 150 million work days are lost each year due to 'flu related illness at a cost of £6.75bn. (6)

According to the UK Federation of Small Businesses the ‘flu bug during the winter of 1999-2000 cost small companies £750m in lost productivity. (7)

References:

1. Watson JM. Surveillance of influenza. In Nicholson KG, Webster RG, Hay AJ, eds. Textbook of Influenza, pp 207-16. Oxford: Blackwell Science, 1998.
2. Keech M, Scott AJ, Ryan PJ. The impact of influenza and influenza-like illness on productivity and healthcare resource utilization in a working population. Occup.Med.(Lond) 1998;48:85-90.
3. Nguyen van Tam JS. Epidemiology of influenza. In Nicholson KG, Webster RG, Hay AJ, eds. Textbook of Influenza, pp 181-206. Oxford: Blackwell Science, 1998.
4. Goddard NL, Joseph CA, Zambon M, Nunn M, Fleming D, Watson JM. Influenza surveillance in England and Wales: October 1999 to May 2000. Commun.Dis Public Health 2000;3:261-6.
5. Leese J, Tamblyn SE. Pandemic planning. In Nicholson KG, Webster RG, Hay AJ, eds. Textbook of Influenza, pp 551-9. Oxford: Blackwell Science, 1998.
6. Consumer Health Information Centre. Colds and flu at a glance. 1998. www.chic.org.uk/campaigns/older_campaigns/coldsflu_1998/glance.htm.
7. Sunday Business. 'Flu bug costs £750m. 9 January 2000.

• If you have some, but not all of the ‘flu symptoms above, you may still be suffering from ‘flu.
• If you have taken a paracetamol or aspirin containing remedy your temperature will have been reduced.

References:

1. Nicholson KG. Human influenza, Ch 19 in Textbook of Influenza, ed. Nicholson KG, Webster RG and Hay AJ. (1998).