Leading article: Suffolk is only one battle in a long global war

The outbreak of bird flu in Suffolk is deeply disturbing. In terms of scale, Britain is now the centre of the worst outbreak in Europe. The relatively low-key public reaction to the eruption, however, would suggest that at last we have apparently learned not to panic. Had it occurred a year or two ago, when fears of a human pandemic were higher, the debate might have been more hysterical, leading to calls for unnecessarily draconian measures such as massive culls of wild birds as well as domestic poultry.

This time we are in calmer waters; too calm, perhaps, for there are several puzzles about the H5N1 outbreak that we must get to the bottom of before we can start to breathe easier. One is how the virus got into what is supposed to be a bio-secure environment. The last time the avian flu scare hit Britain, scientific opinion held that birds kept in the open were at greatest risk of infection. The assumption was that a small organic farm would be the likely point of contact between farmed birds and wild carriers. "Bring the birds in" was the cry. But this time the birds were in already and yet the virus got in, too.

Another mystery concerns the wildfowl that were presumably responsible for bringing the virus to the farm. The virus travels with sick migrating birds. But this is February - weeks ahead of the annual spring migration that will bring millions of ducks and geese to Britain's shores and wetlands. Of course, global warming may have thrown this pattern awry as it has so many others but it remains perplexing.

A third area of concern has nothing to do with the Suffolk farm, or the vexed question of whether the Department for Environment, Food and Rural Affairs (Defra) acted quickly enough last week before beginning a turkey cull. This is the spread of human deaths linked to the virus in new parts of the world.

One by-product of a growing sense of ennui about bird flu has been a relaxation in once-vigilant reporting. Yet this past year has been a busy one for the disease with about 18 people confirmed dead in connection with the virus in Egypt and one at the weekend in Nigeria.

This should ring alarm bells, for Africa could well turn out to be a far more dangerous zone for H5N1 than Asia has been. Poverty there is worse, standards of health care are lower, veterinary inspection is weaker, or in some cases lacking altogether, and governments, especially in war-torn areas, are likely to be slow to see tackling outbreaks as a priority.

While we in Britain concentrate on eradicating the latest outbreak in Suffolk, we need to keep a far closer eye on the African continent than we have been doing. As with the HIV/Aids epidemic, Africa, not Europe - let alone Suffolk - is likely to be at the centre of the storm.

It is right and proper that in this country we are learning to live with threats of pandemics and retain a sense of proportion as well as awareness that it is still only a threat. After all, the longer that H5N1 survives without mutating into a virus that transmits between humans, the less likely it is to do so. This particular form of avian flu is now about a decade old and many scientists believe that if H5N1 was going to mutate in this fashion, it would have done so already.

But when Defra has contained the disease in Suffolk, we must not fall once again into the trap of feeling that the wider threat has been dealt with. The H5N1 strain could still evolve into the pandemic that we have long dreaded and even if it does not, that "job" might fall to some other, similar, strain of avian flu. The potential for a pandemic, in other words, will still be out there and demands continued vigilance.