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Archives - SDAV
ALERT
Prepared by: Michael J. Huerkamp, DVM, Diplomate ACLAM and
Lois A. Zitzow, DVM
February 11, 2000
Harlan Sprague-Dawley (HSD) has reported an outbreak of sialodacryoadenitis
virus (SDAV, coronavirus) originating in a surgical unit in Madison,
Wisconsin (www.harlan.com), but disseminated nationally to research
institutions in at least 15 states and one Canadian province over
the past two weeks. Anecdotal evidence suggests that rats originating
from Prattville, AL production colonies may also be a source. However,
as outbreaks of this nature often involve some degree of rumor,
innuendo, unfounded accusations, exaggeration, and hysteria, actions
and interpretation must be tempered. A mitigating factor in the
widespread national distribution of this disease appears to be the
apparent mixing of rats from different production colonies in HSD
trucks to facilitate regional delivery to research institutions.
Thus, shipping crates containing rats, HSD delivery personnel, and
receipt personnel at destination institutions all could become contaminated
with SDAV through direct or indirect contact with crates from Madison
and be a source of transmission.
The DAR is closely monitoring rat colonies for signs of disease
and will be checking sentinels for seroconversion shortly. To date,
no outbreaks have been reported in Georgia or in any contiguous
state except Alabama. We have HSD rats in the Dental, Physiology,
Rollins, and Woodruff Memorial Research buildings. We have not received
any rats from the building that was the source of the outbreak,
but have received rats from production colonies in both Madison
and Prattville as well as other sites.
Previous outbreaks of SDAV at Emory University were limited to
the WMRB in 1994 and 1988. Typically, infection with SDAV is characterized
by ocular squinting, corneal ulcerations, mild pneumonia, sneezing
and often spectacular “mumps-like” swelling of salivary
glands in the neck. However, outbreaks can be almost clinically
silent. For example, our outbreak in 1994 was asymptomatic except
for high mortality in adrenalectomized rats. Because of general
malaise and pneumonia, SDAV-infected rats should perform abnormally
in behavioral paradigms and are at high risk of dying under anesthesia,
respectively. The disease is highly infectious and spreads rapidly
through a colony affecting all exposed rats, but, providing new
susceptible animals are not added to the population, it will rapidly
run its course. Mice, humans and other species are not susceptible
to infection. Research personnel observing unexpected deaths in
anesthetized rats or experimentally-manipulated rats or observing
clinical signs in rats should report any findings immediately to
the veterinary staff (7-3248).
Based upon information that we have, the DAR has discontinued ordering
rats from Madison and Prattville production facilities and re-emphasized
the importance to our staff of spraying crates with disinfectant
before unpacking rodents. It is possible that our moratorium as
well as control measures enacted by HSD may impact rat availability
for some users.
We are monitoring the situation and will provide updates as needed.
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