Re: Kazakhstan:3,000 endangered antelopes dead of unknown causes
http://promedmail.org/pls/apex/f?p=..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,82910
Archive Number 20100525.1740
Published Date 25-MAY-2010
Subject PRO/AH> Undiagnosed die-off, antelopes - Kazakhstan (03): infectious, RFI
UNDIAGNOSED DIE-OFF, ANTELOPES - KAZAKHSTAN (03): INFECTIOUS, REQUEST
FOR INFORMATION
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[1]
Date: Tue 25 May 2010
From: David Thomson <thomson.david48@gmail.com> [edited]
If this outbreak is primarily due to a pasteurella as speculated, it
may be of interest to compare it with the one responsible for deaths
amongst rocky mountain bighorn sheep in the USA.
I'd further guess that the apparent scale/speed of this outbreak
might also be somewhat novel for a pasteurella outbreak amongst a
wild, free-ranging species, but not necessarily so for FMD as also
speculated.
--
David Thomson
Sub-regional Animal Health Specialist
SPC (Secretariat of the Pacific Community)
Port Moresby, Papua New Guinea
<thomson.david48@gmail.com>
[The following abstract may add some background to Dr Thomson's just
comment, in relation to Saiga antelopes:
Abstract: _Pasteurella haemolytica_ leukotoxin is a pore-forming
cytolysin which acts as a virulence factor in pasteurellosis of
domestic ruminants. Leukocytes from cattle, sheep and goats are
susceptible to leukotoxin-induced lysis; however, leukocytes from
non-ruminant species so far tested are resistant to
leukotoxin-induced lysis. Neutrophils obtained from 3 white-tailed
deer, 4 Saiga antelope, an Addra gazelle, a Grant's gazelle and a
Sable antelope were tested for susceptibility to the lytic effects of
_P. haemolytica_ leukotoxin using lactate dehydrogenase release.
Results were compared to those obtained using neutrophils from a
steer and cultured bovine lymphoma cells. Neutrophils obtained from
all these ruminants, except the Addra gazelle, were susceptible to
_P. haemolytica_ leukotoxin. Individual variation among the Saiga and
the deer did not appear to be due to the percentages of neutrophils
or the percentage of contaminating erythrocytes in the cell
preparations. !
(A. W. Confer,, K. R. Simons1, M. T. Barrie & K. D. Clinkenbeard
(1990). Effects of _pasteurella haemolytica_ leukotoxin on
neutrophils from white-tailed deer and several exotic ruminant
species. J Vet Res Communication, Vol 14, 3, 175-180).
Results of the laboratory investigations in Kazakhstan, with special
reference to FMD virus, are urgently anticipated.
The global weight of major epizootics and the strategic position of
Kazakhstan within the Asian realm is demonstrated by the started
construction of a USD 103 million reference laboratory for the study
of contagious animal and human diseases in Almaty. The facility is
being funded through the U.S. Cooperative Threat Reduction program. -
Mod.AS]
******
[2]
Date: Tue 25 May 2010
From: Peter Roeder <peter.roeder@taurusah.com>
While I agree with your moderator's comments about considering FMD in
the differential diagnosis of mortality in Saiga antelope, I would
like to point out that there is another contender which merits
serious attention, and that is peste des petits ruminants (PPR). The
PPR host range among small ruminants is broad, and, in outbreaks
encountered in zoological gardens in the Middle East, many different
species of antelope have succumbed. It is also known that PPR has
been responsible for deaths of wild sheep in Pakistan recently. We
know virtually nothing about the susceptibility of species such as
Saiga antelope, but it is highly likely that they are very
susceptible and would suffer high morbidity and mortality in virgin
epidemics.
In the last decade or so, PPR has greatly extended its range into
China and the Central Asian Republics, confirmed in the case of
Tajikistan, and is a cause for concern in Kazakhstan and Uzbekistan
even though presence of the virus might not have been confirmed in
either country. I would like to stress that in many countries, PPR
has not been recognised on 1st introduction into goats and/or sheep
herds/flocks. Repeatedly, its recognition has been delayed for
considerable periods of time, even years, because of confusion with
pasteurellosis. PPR in small ruminants has a marked pneumonic
component, and, as in all pneumonic conditions of small ruminants, it
is usual to be able to isolate pasteurella organisms (_Manheimia
haemolytica_) on bacterial culture of lung. Unspecified "poisoning"
is also commonly suspected. It is perhaps understandable that newly
affected countries do not have dedicated diagnostics in place for all
especially dangerous pathogens, but there is no reason why the
diagnosis should not be undertaken by use of the free service
provided by the World Reference Laboratory for Morbilliviruses hosted
by the UK's Institute for Animal Health Pirbright Laboratory (e-mail
Dr Chris Oura for assistance: <Chris.Oura@bbsrc.ac.uk>).
The few Saiga and other antelope species still remaining in the wild
in Central Asia are a valuable global resource which, like all
free-living ungulates, are under severe threat from human activities
including habitat destruction and livestock diseases. We do not seem
to have a mechanism to detect with accuracy the aetiology of disease
in such animals let alone any ability to do anything about it.
Repeatedly, we see in ProMED posts reports of wildlife disease, even
die-offs, and yet rarely is there a systematic investigation leading
to a definitive and credible diagnosis. In 2010, one could perhaps
hope for better.
--
Dr Peter Roeder, BVetMed, MSc, PhD, MRCVS, OBE
Taurus Animal Health
Headley Down Hampshire GU35 8SY
UK
<http://www.taurusah.com>
<peter.roeder@taurusah.com>
[Thanks to Dr Roeder for rightly reminding us of PPR as a very
important potential health hazard for (small ruminants) wildlife in
Asia. In addition to PPR, other diseases sometimes mistaken to be
caused by _Pasteurella_ organisms, such as orbivirus diseases
(bluetongue, EHD), also deserve consideration.
This moderator fully shares Dr Roeder's concerns about the plight of
disease-threatened wildlife and his suggestion to affected countries
to approach available expertise resources for diagnostic support. The
cooperative investigation into FMD virus replication in heart muscle
of wild cloven-foot animals by a newly developed test, just proposed
by a research worker at the Pirbright laboratory (today's 25 May 2010
posting 20100525.1736) is an additional, welcomed example and
relevant to the issue at stake. - Mod.AS]