H E A L T H
CANINE LEISHMANIASIS CASES CONFIRMED IN 21 STATES
Results of DNA and blood tests obtained by
scientists at North Carolina State University's College of Veterinary Medicine and the
National Centers for Disease Control and Prevention (CDC) have confirmed cases of visceral canine leishmaniasis -- a rare, often
fatal tropical disease that can be transmitted to humans and other animals -- in 21 U.S. states and southern Canada.
The test results suggest leishmaniasis is
substantially more widespread in North American canine populations than originally
"We have a very serious disease that leads
to chronic debilitation and kidney failure in dogs, and can lead to their death.
Unfortunately the disease is extremely hard to diagnose," says Dr. Edward Breitschwerdt, professor of small animal internal medicine at
NC State, who helped lead the research effort to facilitate more widespread testing for leishmaniasis after diagnosing the disease at
a New York hunt club last spring.
Until researchers determine how leishmaniasis
is transmitted in the United States, the threat to human health is not completely
known, Breitschwerdt says. Direct contact transmission would pose a far smaller risk than
transmission by insects like sand flies or ticks. That mode of transmission, Breitschwerdt says, could create a
public health concern.
Leishmaniasis is a parasitic infection and most
often occurs in rural areas of the tropics and subtropics, where the most common
species of the parasite is transmitted by the bite of an infected female sand fly. Symptoms of leishmaniasis include skin lesions, nose
bleeds, swollen lymph glands, weight loss, seizures, hair loss,
kidney failure and swollen limbs and joints.
The disease is potentially fatal in humans, but
can be treated. While there is no cure for leishmaniasis in dogs, it can be put into
Breitschwerdt says leishmaniasis is prevalent
in southern Europe, India and South America, but, until very recently, was not
thought to be present in the United States. "I think there is the possibility that there could have been human cases in the United
States that weren't diagnosed," he says. Ongoing research efforts
should allow scientists to determine the source of the U.S. canine
Leishmaniasis, how it's being transmitted, and if the cases in different states come from the same strain of the organism.
Breitschwerdt and his colleagues implemented
the new diagnostic tests at the College of Veterinary Medicine last spring in response
to a disease outbreak among foxhounds at a New York hunt club. When
foxhounds at the club began losing weight and suffering from skin lesions, seizures, swollen limbs and joints, and in most cases fatal
kidney failure, the club's attending veterinarian turned to veterinary medicine researchers at NC State for help. Using the DNA
and blood tests, Breitschwerdt and his team were able to confirm that the disease was canine leishmaniasis.
The NC State team has been collaborating with
the CDC, the Walter Reed Army Institute of Research and the Dutchess County (New
York) Department of Health to investigate the New York Leishmaniasis outbreak.
In conjunction with the CDC, they've tested
foxhounds from other regions and identified canine leishmaniasis in 21 other states,
including North Carolina, and southern Canada. "So we've gone from
an outbreak in New York to literally a national epidemic that's probably
been smoldering for 15 to 20 years," Breitschwerdt says. It's still
not clear how the dogs in New York became infected.
Breitschwerdt's research and testing team is
made up of more than a dozen NC State students, clinicians, pathologists and other
researchers, including Dr. Michael Levy, professor of parasitology;
Dr. Amanda Gaskin, internal medicine resident; Dr. Adam Birkenheur, graduate student; and Lindsay Tomlinson, pathology instructor.
Dr. Edward Breitschwerdt, 919-513-6234