Leishmaniasis, dogs - USA (07)
Jeffrey Shaw
jshaw at tba.com.br
Sun May 14 21:32:08 BRT 2000
Date: Sun, 14 May 2000 10:28:14 -0400 (EDT)
From: ProMED-mail <promed at promed.isid.harvard.edu>
Subject: PRO/AH> Leishmaniasis, dogs - USA (07)
LEISHMANIASIS, DOGS - USA (07)
*******************************
A ProMED-Mail post
<http://www.promedmail.org>
[see also:
Leishmaniasis, dogs - USA (02) 20000424220647
Leishmaniasis, dogs - USA (03) 20000426223625
Leishmaniasis, dogs - USA (04) 20000430003928
Leishmaniasis, dogs - USA (05) 20000503094746]
Date: 13 May 2000
From: Elizabeth Lundgren, DVM <Watusi at VIN.com>
Dr. Ed Breitschwerdt, Chairman of the ACVIM (American College of Veterinary
Internal Medicine) Board of Regents, has asked me to make this disease
information available to anyone who might find it of interest.
Canine Visceral Leishmaniasis- United States 2000
- --------------------------------------------------
The Division of Parasitic Diseases, National Center For Infectious
Diseases, CDC, has been collaborating since February 2000 with the Dutchess
County (NY) Department of Health (DC-DOH ), the Walter Reed Army Institute
of Research (WRAIR), the New York State Department of Agriculture & Markets
(NYS-DAM), the New York State Department of Health (NYS-DOH) and the North
Carolina State University College of Veterinary Medicine (NCSU-CVM) to
investigate an outbreak of visceral leishmaniasis among foxhounds at a
kennel (Hunt Club A) in Dutchess County.
On 11 Feb 2000, CDC was called by Edward Breitschwerdt, DVM, Professor of
Veterinary Internal Medicine, NCSU-CVM, who reported the diagnosis of
leishmaniasis in foxhounds from Hunt Club A.
Beginning in the late summer of 1999, a number of foxhounds at Hunt Club A
had developed illness with manifestations including bleeding, wasting,
seizures, hair loss, skin lesions, kidney failure, and swollen limbs and
joints; there have been several deaths. Several of the ill dogs were sent
to NCSU-CVM for diagnostic studies, and cytopathologic examination of joint
fluid of one of the hounds revealed amastigote forms of _Leishmania_ spp.;
this was confirmed at autopsy of several dogs, and organisms were isolated
and grown in culture.
These findings were reported to John Huntley, DVM, New York State
Veterinarian (NYS-DAM), Millicent Eidson, DVM, MA, State Public Health
Veterinarian (NYS-DOH), and Michael Caldwell, MD, MPH, Commissioner,
DC-DOH, and further field and laboratory investigations were initiated.
Diagnostic studies at the Hunt Club A kennels revealed a high rate of
leishmanial seropositivity (39/93, 42%) among the group of foxhounds and
aspiration or biopsy of lymph nodes and other tissues of 15 seropositive
dogs resulted in isolation of _Leishmania_ spp. from 15 dogs.
The species infecting the New York foxhounds was confirmed in early April
by the Leishmania Section of the Division of Experimental Therapeutics,
WRAIR, as _Leishmania_ of the species complex donovani. More precise
identification of the organism and its origin is in progress.
Serologic screening of foxhounds (n=63) and other breeds of hunting dogs
(n=28) in neighboring kennels has revealed no additional cases of
_Leishmania_ infection in Dutchess County. Attempts to demonstrate
infection in wild rodents and horses in the vicinity of the kennel through
examinations of blood and tissue samples have also been negative although
the numbers of animals examined to date has been small. Serum specimens
drawn from the attending veterinarian and 5 employees of Hunt Club A who
worked closely with the foxhounds tested negative for antibodies to
leishmaniasis.
Surveillance for insect or other potential vectors will be initiated by the
DC-DOH in June. Circumstantial evidence suggests the NY foxhounds may have
become infected during hunts in other states. Like most Hunt organizations,
Hunt Club A travels extensively during the active season and foxhounds from
different packs have opportunities to mix with each other in a number of
states. _Leishmania_ sp. had been identified previously in dogs in the
United States in: Oklahoma in 1980; Kansas in 1982; Ohio in 1988; Michigan
in 1989; and Texas and Alabama in 1991. There was no evidence of infections
in humans or in pet dogs in the vicinity of the infected dogs reported
previously in other states.
Leishmaniasis is a parasitic (protozoan) infection transmitted naturally by
the bite of an infected female sand fly (phlebotomid). At least 20
different species of _Leishmania_ parasites are known to cause infection in
humans. How the infections in dogs in New York and other states are being
transmitted is unclear. Although sand flies potentially capable of
transmitting certain species of _Leishmania_ do occur in the southern
United States, no species of sand flies that are known to be vectors of _L.
donovani_ have been reported.
Experimental evidence of dog-tick-dog transmission of _Leishmania_ sp. has
been reported but it is not known if this occurs in nature. There have been
anecdotal reports of direct dog-to-dog transmission of visceral
leishmaniasis, and these foxhounds commonly have close and intense contact
with each other. These infections can also be transmitted from person to
person through the sharing of needles. Dog-to-dog transmission without the
intermediary of insect vectors has been reported in dogs in northern
European countries from dogs imported from southern Europe where the
infection is enzootic. To date there have been no documented autochthonous
cases of visceral leishmaniasis in humans in the United States. Although
direct transmission from an infected dog to humans has never been reported,
it is speculated to be possible, and immunocompromised persons would be
theoretically at greatest risk.
With the cooperation of State Public Health and Agriculture agencies and
Foxhound Hunt Organizations, investigations are in progress to identify
infections in dogs and other potential hosts, to determine how it is being
transmitted, and to determine the potential public health significance of
this infection. The Foxhound Organizations have recommended a temporary
cessation of interstate movement of foxhounds pending the collection of
more detailed information on the extent of this infection and its mode of
transmission.
To date, sera from more than 1000 foxhounds and other hunting dogs from
Eastern states have been tested at CDC. Preliminary serologic results have
revealed the presence of seropositive dogs in Virginia (2 kennels),
Michigan (1 kennel) and Maryland (2 kennels); samples of tissue from
seropositive dogs are being obtained and placed into culture (the
sensitivity and specificity of the serologic test are not absolute and
require confirmation by isolation).
State public health veterinarians and practicing veterinarians who provide
services to Hunt clubs and foxhounds are asked to cooperate in this
investigation by acting as local sources of information, by facilitating
the collection of sera from foxhounds and other dogs with possible exposure
to known infected dogs and by participating in other aspects of the
investigation.
- --
Elizabeth Lundgren, DVM
Veterinary Information Network (VIN)
Watusi at VIN.com
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