By Angela Hodges
Researchers wanting to understand how epidemics spread have used data tracking the movements of individual mobile phones, said Professor Neil Ferguson in Liverpool yesterday. By establishing how widely people move in their daily lives, they have determined their infectious potential.
Professor Ferguson was delivering the BA Charles Lyell Award Lecture at the Festival of Science.
The data is used to produce a model that best represents what actually happens in a flu pandemic. Using this model, researchers can simulate a real flu epidemic to test which measures are most likely to block the spread of infection.
Fergusson, from Imperial College London, has developed a model of the spread of the particularly severe form of avian influenza or 'bird flu' caused by the H5N1 virus.
It has the greatest potential to become a devastating pandemic, giving rise to death worldwide on an unprecedented scale. For this reason the UK government has placed it at the top of a register of threats based on relative impact and likelihood of occurrence.
Although an H5N1 pandemic is very unlikely in the near future, it is the ability of this virus to cause death in almost all cases of infection, combined with the vast number of people living in the world, which marks it out from even serious flu outbreaks of the past.
Using information gained from past events such as the Spanish flu pandemic of 1918-1919, Ferguson built up a picture of how flu viruses spread through a population. The Spanish flu killed 14 million people worldwide within 8 months.
Today, people in the UK talk to roughly 12 people each day on average.
Children are key transmitters of infectious diseases as a result of their increased susceptibility to infection and their daily contact in school with many other children and adults.
Professor Ferguson's model shows that closing schools will reduce the number of people developing illness, and subsequently dying, by as much as a third.
On the other hand, closing the borders to the UK will have a negligible effect on the spread of infection.
The model will continue to be developed to provide vital information for dealing effectively with future flu outbreaks, to minimise loss of life.