IT IS grotesque. Across Britain, thousands of slaughtered farm animals are
burning on giant pyres. The air is thick with the smell of burning straw and
meat. Is this medieval measure really the best way to deal with infectious
disease in the 21st century?
We鈥檙e talking foot and mouth disease, of course, which spread rapidly and
invisibly, emerging at a dozen sites last week. All movement of livestock around
the country has stopped, infected farms have been quarantined and their animals
slaughtered. Politicians and officials across the European Union have their
fingers crossed that these draconian measures will be enough to halt the
outbreak. Many farmers already face ruin.
The virus is a difficult customer. A large reservoir of infection exists
around the globe, and it is highly contagious, spreading like flu on the breath
of infected animals. It can also be transmitted by meat imported from infected
areas. How do you fight an enemy like this? One option is to throw a cordon
sanitaire around the EU to keep out infected meat. This is already supposed to
be in place. But repeated outbreaks of foot and mouth and swine fever suggest
that the defence is easily breached.
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To European eyes, countries such as Australia and the US go overboard in
their strict enforcement of rules on imported foodstuffs. But the US hasn鈥檛 had
an outbreak of foot and mouth since 1929鈥攑erhaps eternal vigilance is a
price worth paying. But for Europe, this cannot be the only answer. No amount of
enforcement will stop the virus crossing borders on the wind or in a trucker鈥檚
sandwich.
Another line of defence would be a long-acting vaccine. But it does not yet
exist. Today鈥檚 vaccines against foot and mouth are far from perfect. The most
important problem is that they are made from whole, killed virus particles. This
means vets cannot tell infected and vaccinated animals apart. Importers will not
buy vaccinated livestock in case the animals are infected. But there is a
glimmer of hope. Researchers in the US have an experimental vaccine made only
from parts of the foot and mouth virus that does let vets separate the
vaccinated from the infected. If it lives up to expectations, this vaccine could
help quell an outbreak
(see 鈥淲hy the slaughter?鈥�).
Once clear of the disease, a country could use the vaccine to keep itself
free from further outbreaks. This would be a big change for Europe and North
America, where for economic reasons the policy has been to eradicate diseases by
slaughter and keep huge populations of susceptible animals. But with more and
more people and animals moving around the globe, and meat production rocketing
in areas where disease control is limited, this policy must be reviewed.
There is a strong case for more research into animal vaccines鈥攁nd not
just against foot and mouth. It is only a matter of time before the emerging
Nipah virus escapes from South-East Asia. Will we slaughter pigs infected with
that too? And let鈥檚 not forget that Nipah attacks people as well as animals. By
protecting them, we protect ourselves.
