In reply to John Stainforth:
> Is it not like many other viral infections, such as Mumps, which is pretty easy to catch? I recently caught that off someone who was feeling somewhat unwell, but had not developed symptoms, simply by shaking hands. Mumps also has an incubation period of about 20 days.
No. It's tempting to think of viral infections as like mumps, or chickenpox, or flu, but infectivity varies. Think of Hep C or HIV - actually quite hard to catch.
In this epidemic epola is turning out to be about 6 times less infectious than flu, or 3 times less infectious than mumps. Also, importantly, when people are infectious they are highly symptomatic and are not highly infectious during the incubation stages.