With bird flu spreading through cattle herds in the US and infecting humans, the diseases poses a severe threat to wild life, poultry and also people. What can mathematical modelling do to help?
We look at the recent rise in measles cases, why it has led to a national health incident being declared, and what can be done to avert the threat.
At the beginning of an epidemic the number of infected people grows exponentially. But why does the number e appear in descriptions of this growth?