Weighing up the risks
How should individuals and governments respond to
the possibility of new outbreaks?
There is a small but finite chance
that a sizeable asteroid is on a collision course with Earth. Most
people would agree that the risk is so low that there are more
important things to worry about.
What about a possible flu pandemic?
It's a difficult call. History suggests we can expect another
global pandemic, yet it is devilishly hard to predict when. On the
other hand, if one did strike its impact would be immense.
So how does a government respond to a
low-risk high-impact scenario? It may seem obvious that drugs and
vaccines should be stockpiled and plans put in place to cope with
an outbreak. But which drugs and vaccines? Such stocks cost money
and somebody has to do all that planning. Is it a good use of time
and money when there are so many other priorities? What about other
possible challenges - XDR-TB (extensively drug-resistant
tuberculosis)? Antibiotic-resistant bacteria? Chlamydia and other
sexually transmitted infections?
Governments will seek advice, and
tools such as modelling can provide useful input. Yet knowledge
will be incomplete and possibly disputed. And other factors will
influence decisions - such as a government's political philosophy,
economic circumstances and pressure from the media.
Individuals will face different
issues. Sales of chicken plummeted when avian flu was discovered in
Norfolk, while uptake of the MMR vaccine dropped when fears of a
link with autism were raised. It is tempting to call such responses
irrational, given the extremely low risks involved.
But they can also be seen as sensible
cost-benefit analyses – why take even a small (or perceived) risk
if it can be easily avoided and appears to have no consequences? A
greater risk will be tolerated if there is a corresponding
trade-off in benefits - so the possibility of harm from mobile
phones is more than outweighed by their value to us.
In terms of emerging infections, our
behaviour will depend on our perceptions (is the threat real?) and
the extent to which proposed measures inconvenience us (what will I
have to give up?) - and, of course, our individual personalities.
Voluntarily avoiding chicken for a few weeks 'just in case' is very
different from not being allowed to leave the house.