COUNTRIES that are officially free of rabies are still at risk from closely
related viruses, virologists warned last week. Various strains found in bats are
a direct threat to humans, and could also trigger an outbreak among other
animals.
鈥淲e must make sure governments remain vigilant,鈥� says Tony Fooks, head of the
rabies research group at the Veterinary Laboratories Agency in Weybridge,
Surrey. His warning, to a conference in London, coincides with a report by Liam
Donaldson, Britain鈥檚 chief medical officer, outlining the government鈥檚 plans for
tackling re-emerging diseases such as TB, as well as new threats like Ebola.
In Europe, two relatives of the rabies virus, European bat lyssaviruses 1 and
2, are causing concern. People bitten by bats with EBLs can become infected, and
at least three have died in the past 25 years. But perhaps the biggest threat to
people is from an EBL epidemic in other animals, triggered by bats.
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So far EBL viruses have spilt over into animals only once, killing three
sheep in Denmark in 1998. But other cases may have gone unreported. And Noel
Tordo of the Pasteur Institute in Paris says that the normal animal vaccine
against rabies would be useless. 鈥淓BLs are genetically distinct from the classic
rabies virus, so vaccinated animals wouldn鈥檛 be protected,鈥� he says. That could
undermine a successful campaign in western Europe to wipe out rabies by feeding
bait laced with vaccine to red foxes.
EBLs are found mainly in serotines, bats most common in mainland Europe. But
in 1996, a bat that bit two people in Sussex tested positive for EBL2.
鈥淲e must be very vigilant because we can鈥檛 stop bats flying into the UK,鈥�
says Fooks. 鈥淚t鈥檚 imperative for people bitten by animals to wash wounds
immediately and seek medical treatment.鈥�
Like most of Europe, Australia is officially rabies-free, but another rabies
relative, Australian bat lyssavirus, has been discovered in flying foxes. It has
killed at least two people recently. Elsewhere in the world, classic rabies
remains endemic in animals, especially dogs. Up to 70,000 people die of the
disease each year in Asia and Africa.
Underscoring the risk of diseases popping up unexpectedly, Albert Osterhaus
of the Erasmus University in Rotterdam presented a surprise case of cowpox in
humans. A young girl turned up with awful facial scabs at Utrecht University
Hospital. It turned out she鈥檇 brought home a sick rat that died the next day.
鈥淲e dug up the rat and isolated a virus, showing it was the same one affecting
the girl, a cowpox virus,鈥� said Osterhaus.
He says that there might be more cases now that children are no longer
vaccinated against smallpox with vaccinia, the cowpox virus. 鈥淒octors should
keep their eyes and ears open.鈥�