THE notion of 鈥渆merging diseases鈥� erupted into the public鈥檚 consciousness in
the mid-1990s, following outbreaks of Ebola in Africa and, of course, the AIDS
pandemic. It conjured up images of infected people travelling the globe, leaving
explosive epidemics in their wake. Today, emerging diseases are still on the
agenda, but those unwitting carriers have been replaced by the spectre of
bioterrorists deliberately unleashing killer diseases.
The drama of these scenarios is undeniable. But they miss the mark. There is
a much more common鈥攁nd neglected鈥攚ay in which emerging diseases
impinge on our health. The real enemies are not even human. They are our furry
and feathered friends.
Globalisation of trade, growth of cities and intensification of agriculture
are all giving animals new opportunities to spread their pathogens to people.
HIV鈥檚 likely leap from chimps to humans is simply the best-known example. In the
past year or so, Nipah virus jumped from bats to pigs to people in Malaysia,
mosquitoes spread dengue fever in Texas, rodents spread hantavirus in Panama and
tularemia in Kosovo. Last September, birds from the eastern hemisphere probably
brought West Nile virus to the west, killing seven New Yorkers.
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That outbreak took weeks to diagnose. Yet there were obvious clues: crows had
been dying all over the region weeks before the first human cases. An alert vet
at a New York zoo had even sent some crows for testing. But being an animal
doctor, she sent them to the Department of Agriculture, which couldn鈥檛 identify
the foreign virus. Crow samples eventually made it to the people doctors at the
Centers for Disease Control and Prevention in Atlanta, who had the means. Only
then did they realise what had been killing New Yorkers.
Communication between vets and medics is just as bad the world over. And
despite New York鈥檚 wake-up call, things don鈥檛 seem to be improving in the US.
Ornithologists fear that migrating birds could already have spread West Nile
virus all over the continent. Specialists in wildlife diseases want to hunt for it
systematically in healthy wild birds, which might reveal where it could strike humans again
(see 鈥淏eware the birds鈥�).
But the medical establishment would rather watch for new human cases鈥攁nd
more dead crows.
They have one valid point: wildlife epidemiology is a much more difficult,
uncertain and costly enterprise than medics are used to. Even so, we need to
focus more on wild animals if we are to protect ourselves from the next
infection. To do that, DVMs and MDs must find ways to share information more
effectively. It鈥檚 good that veterinary labs across the US are setting up a
network to monitor emerging animal diseases, but they need to keep in touch with
people doctors too.
While the medical profession insists on distinguishing between human animals
and other kinds, many pathogens do not. Because they can bridge that gap, so
must we.
