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)
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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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