A FATAL tropical disease has infected large numbers of foxhounds in the US.
Public health officials fear that humans may contract the disease if the dogs
come into contact with sandflies, which transmit the parasite that causes
leishmaniasis.
Late last year, the Millbrook Hunt Club in New York State realised that many
of its foxhounds were sick and dying. The dogs were losing their hair, they had
skin lesions, swollen limbs and joints, and were wasting away. When vets
analysed fluid from the joints of one dog they found the leishmaniasis
parasite.
This disease, which in humans can cause fever, anorexia, diarrhoea and
darkening of the hands and feet, is commonly found in the Mediterranean and the
tropics. It can kill humans. Usually, North Americans鈥攁nd their
dogs鈥攐nly get the disease if they travel to the tropics. So Peter Schantz
and his colleagues at the CDC were mystified when they learned that half the
foxhounds at Millbrook tested positive.
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They tested other dogs living in the area, as well as horses and wild
rodents. All the tests were negative, as were those on the kennel鈥檚 personnel.
But hunting clubs often travel, so they advised the Masters of Foxhounds
Association of America, based in Leesburg, Virginia, to suspend all travelling
for this year鈥檚 season while they tried to work out what was going on.
By the second week of July, they鈥檇 tested 6845 of around 12 000 foxhounds
registered with the MFHA. At least 12 per cent of the dogs have some antibodies,
suggesting that they have been exposed to the parasite. Around 2 per cent of the
dogs have a strong response on the antibody test, indicating the need for more
testing to see if they are actively infected, says Dennis Foster, executive
director of the MFHA.
鈥淲e have found infection now in 29 states and the Ontario province of
Canada,鈥� says Schantz. Public health officials recommend putting down infected
dogs or placing them in quarantine. They hope that these measures will be enough
to contain the outbreak.
So far, tests on more than 450 domestic dogs from 40 states have all proved
negative. And there have been no human cases. 鈥淲e believe we have it in
control,鈥� says Foster. 鈥淭hose hunts that are completely negative will be able to
resume as normal this season.鈥�
Corrie Brown of the University of Georgia in Athens, an expert on diseases
that can be transmitted from animals to humans, says that leishmaniasis is
having a 鈥渧ery scary introduction into the US. We鈥檙e probably going to see more
leishmaniasis in humans as a result.鈥� Epidemiologists are unsure how the
parasite entered the country. 鈥淗ow did it get in? Nobody really knows,鈥� says Brown.
