*Camel 'Plague' Mystery Deaths puzzle scientists*

    * Robin McKie, science editor
    * The Observer,
    * Sunday December 23 2007

A camel lies dead at the side of a road near the Saudi capital Riyadh

An unprecedented number of camels across North Africa and the Middle
East died last year, researchers have discovered. The several thousand
deaths have baffled scientists who are probing toxins, antibiotic
pollution, viruses and even climate change as possible causes.

In Saudi Arabia alone, between 2,000 and 5,000 perished inexplicably, it
was revealed in Science last week. The ships of the desert are being
sunk in unusual, and worrying, numbers, the journal warned.

'The numbers of deaths we are seeing at present are unprecedented,' said
camel researcher Bernard Faye, who is based at the French Agricultural
Research Centre for International Development (Cirad). 'A great many
animals are dying and it is not at all obvious what is the cause. The
problem is that there is a real lack of good epidemiological evidence,
and until we can get that we will struggle to find the causes of these
deaths and to find ways of stopping them.'

There were several outbreaks of sudden deaths among camels - which are
exploited for their milk and meat and as beasts of burden in North
Africa and Asia - in many countries last year. However, the worst
occurred in Saudi Arabia. At least 2,000 dromedaries perished in a
region south of Riyadh, the Saudi capital. Unofficial estimates put the
death toll as closer to 5,000.

Initial reports blamed infectious disease, but after Saudi vets sent
blood samples to international laboratories it was announced that the
animals had been killed by contaminants in their fodder. Two particular
contaminants were pinpointed: the antibiotic salinomycin, a supplement
used in chicken feed that is toxic to camels, and a fungal species with
mycotoxins that can cause nerve damage. However, the Saudi government
has shared little information about its investigation and evidence
pinpointing fodder contaminants is disputed by experts. 'Neither
mycotoxins nor any known disease could have killed 5,000 camels in that
short span of time,' said Ulrich Wernery, scientific director of Dubai's
Central Veterinary Research Laboratory.

Camels are associated with hardiness, their ability to survive on small
amounts of drinking water and blood-cooling systems that let them work
in intense heat. But recently reports of camel deaths across the region
have increased dramatically - on top of the Saudi outbreak. Changes in
types of fodder may be linked to immune problems, it is suggested. Other
scientists argue that climate change may be increasing numbers of
disease-bearing insects, while others argue that changes in the use of
camels, which are exploited less for transport and more for milk and
meat today, may be making them more susceptible to disease.

'It is a puzzle, and until we get more information we are not going to
get close to finding an answer,' said Faye.