USDA probes claim that saliva test can reduce post-mortem rabies tests
From ANIMAL PEOPLE, March 2009:
AMES, Iowa–A company called Dyne Immune created web buzz on
February 3, 2009 that a new saliva test to detect rabies might end
the need to confirm suspected cases through post-mortem
examination–but the enthusiasm expressed by rescuers without
veterinary background was not shared by rabies experts, ANIMAL
PEOPLE learned within minutes of receiving the Dyne Immune
announcement and making inquiries.
“No more killing an animal just in case!” exulted one poster
to an online discussion group.
“We have major concerns,” responded U.S. Centers for Disease
Control & Prevention rabies program director Charles Rupprecht.
Explained Chulalongkorn University professor Henry Wilde,
“We had a colleague here in Thailand who also tried to develop a
saliva test for dogs. We spent considerable effort to show that even
if this test is specific and sensitive, it is unreliable. Rabies
virus excretion in saliva is not consistent but intermittent, and
may be absent at any time during the clinical illness. It seems
incredible,” Wilde said, “that such a product has apparently
reached the market in the United States. If it is used at all in an
effort to make a post-exposure treatment decision, it could lead to
deaths and visits by many attorneys.”
Wilde immediately forwarded the Dyne Immune media release and
further information from the Dyne Immune web site to an international
panel of distinguished rabies researchers, all of whom noted the
risk of using a test which may produce a false negative
finding–appearing to clear a rabid animal of suspicion of infection.
“This test for rabies antigen in saliva is generating a
substantial amount of controversy for a number of reasons,” e-mailed
Kansas State University College of Veterinary Medicine rabies
laboratory director Cathleen Hanlon. “Since it is a veterinary
diagnostic test, it would most likely be under the regulation of the
USDA. I will check with my contact at USDA to clarify whether it is
simply experimental at this point rather than ‘approved’ per se by
“We have been in contact with Dyne Immune and have opened an
investigation of Rabies RAPID Screen,” disclosed Laurier P. Couture
of USDA Animal & Plant Health Inspection Service Center for
Veterinary Biologics on February 5, 2009. “If you or any of your
contacts could provide us with additional information concerning this
product or its use we would appreciate it. We are especially
interested in obtaining an actual kit or kit circular from the field.”
The excitement started after the Dyne Immune media release
reached online newsgroups including AR-News, opening with a place
line of Florence, Kentucky, and concluding with an upstate New York
telephone number. The release also appeared on web sites where lay
people discuss health issues, but was not posted to ProMed, the
peer-reviewed International Society for Infectious Diseases e-list
for public health professionals, nor to other mailing lists serving
people who work in rabies prevention.
Claimed Dyne Immune chief executive officer V. James
DeFranco, M.D., “This test can reduce the number of animals
destroyed and save doctors and animal control organizations from the
costs associated with traditional testing.”
But how a test known to produce false negatives can save
animals’ lives was left unclear. If a test produces false positives,
retesting positive outcomes to make sure can be made a routine part
of the testing procedure. Confirmation of a positive finding of
rabies could then be taken as confirmation that the animal should be
euthanized. But if a negative finding does not exclude the
possibility of rabies, then no amount of repetition could ensure
that the animal is not infected.
The Dyne Immune web site included a disclaimer,
acknowledging that “A negative result does not guarantee that rabies
is not present. The screen produces a positive result to killed
rabies virus in non-human mammalian saliva,” the web site explained.
“Results are not quantitative.”
The Dyne Immune test is “Not suitable for screening the
rabies virus in humans at this time,” the site added.
“So that you can get to know Dyne Immune a little bit
better,” the site offered, “we are inviting qualified professionals
to try out and evaluate a Rabies RAPID Screen, free of charge.”
The site provided details of a single trial of the product,
on a suspected rabid kitten at the Warwick Valley Humane Society in
Warwick, New York. Involved in the trial, representing Dyne
Immune, were Gary Monteith, who was identified on the Dyne Immune
web site as “an expert in animal husbandry,” and Michael Huchital,
Huchital circa 1990 started a business called Quality
Antisera Development & Production. He employed Monteith, who was
identified in USDA documents as “a rabbit handler.”
Cited in 1997 for alleged multiple violations of the federal
Animal Welfare Act, Huchital was in March 1999 fined $1,200 by
administrative law judge James W. Hunt.
The USDA Animal & Plant Health Inspection Service appealed
the verdict. Judicial officer William G. Jenson in November 1999
found additional Animal Welfare Act violations, and increased the
fine to $3,750.
Jurisdictional issues raised by the case are often cited in
other Animal Welfare Act enforcement decisions.