The swine flu drama is advancing like wildfire, with the Mexican death count rising steadily and U.S. cases doubling.
Declaring a pandemic is a big official deal.
Will the swine flu become a global pandemic in humans, like AIDS or the "Spanish flu" which killed like 50 million people in 18 months?
A pandemic is an outbreak of a new infectious disease, which causes serious illness and spreads widely from person to person across more than one geographical region. HIV/Aids can thus be described as a pandemic illness — it emerged to infect many people relatively recently. Cancer cannot: it is not by and large caused by infection, and neither is it new.
How does a pandemic differ from an epidemic?
An epidemic occurs whenever the number of cases of a particular disease exceeds the number that would normally be expected. Epidemics of infectious disease can escalate into pandemics, but do not always do so.
Is swine flu going to cause a pandemic?
Probably. Professor Roy Anderson, a leading epidemiologist who is also Rector of Imperial College, London, said yesterday that he considers a pandemic is already under way — the question that remains is how serious it will be. Many scientists were saying the same thing privately even before the World Health Organisation raised the threat level to phase 5 on Wednesday, indicating that it considers a pandemic to be imminent.
