ProMED Digest #205
From: douglaI@prose.dpi.qld.gov.au (Ian Douglas)
Date: Thu, 24 Oct 1996 18:29:06 -0400
Subject: PRO/AH> Equine morbillivirus - Australia: bat reservoir (07)
EQUINE MORBILLIVIRUS - AUSTRALIA: BAT RESERVOIR (07)
====================================================
From: "Douglas, Ian"
Date: Thu, 24 Oct 1996 16:32:00 +1000
Subject: A new bat paramyxovirus
Queensland Department of Primary Industries (DPI) scientists, led by Dr
Peter Young, have achieved a major breakthrough in solving the equine
morbillivirus mystery with the identification of flying foxes (fruit
bats), genus Pteropus, as the natural host of the virus.
A paramyxovirus has been isolated from animals representing three
species of fruit bat. The DPI team, including Kim Halpin and Hume Field
have shown that this bat paramyxovirus is identical to equine
morbillivirus by electron microscopy, immunofluorescence,
neutralisation tests and sequencing of the matrix protein gene.
Previous studies by the research team have shown that the antibody
prevalence rate in flying foxes is about 15% (Emerging Infectious
Diseases Vol 2, 239-240). However there is no indication that the virus
has caused infection of people who have had close contact with these
animals over long periods of time. Nor is there any indication of spread
to other animals, except for the two known occasions when infection
occurred in horses, and subsequently in humans in close contact with
infected horses.
The DPI research team will now concentrate on discovering the method of
transmission of bat paramyxovirus among flying foxes. This information
should provide clues to the mechanism of spill-over to other animals.
These results are being prepared for publication. Requests for further
information on this work should be directed to:
Dr Peter Young - youngp@prose.dpi.qld.gov.au".
K J Dunn
Executive-Director, Animal and Plant Health Service and
Chief Veterinary Officer (Queensland)
[- In the previous 48 hours we have had a series of journalists' reports
come into ProMED but we requested an authoritative report before posting.
Thanks, Ian. MHJ -]
.....................................................................mhj
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From: pharm6@op1.up.ac.za (Jonathan Taylor)
Date: Thu, 24 Oct 1996 18:57:34 -0400
Subject: PRO/AH> FIV in African lions
FELINE IMMUNODEFICIENCY VIRUS IN AFRICAN LIONS
==============================================
Date: Wed, 23 Oct 1996 15:57:40 GMT+2
From: "Jonathan Taylor"
Via: "Veterinary professionals list"
Subject: Re: FIV in Africa
> Date sent: Mon, 21 Oct 1996 11:29:33 -0400 (EDT)
> From: "Susan G. Wynn, DVM"
> To: "Veterinary professionals list"
> Subject: FIV in Africa
> I had a client tell me that an African gamekeeper informed her that most
> of the lions in Africa are FIV positive. She does field work for some
> wildlife preserve in Kenya, so I cannot discount this story completely.
> Does anyone know anything about this?
>
A sizeable population of the lions in the Kruger Park are FIV
positive, but whether this is clinically significant in the short
life span of a wild lion is unknown.
Probably a more pressing problem is that some of the lion in the
Southern part of the park have been diagnosed with TB, probably
infected by Cape Buffalo, infected in turn by cattle bordering the
park.
- ---
Jonathan Taylor
Onderstepoort
South Africa
[- One might wonder whether FIV might have contributed to the recently
reported outbreaks of lethal canine morbillivirus infections ("distemper")
in African lions as well. MHJ -]
.......................................................................mhj
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From: mjn@mailpc.brs.gov.au
Date: Thu, 24 Oct 1996 19:42:23 -0400
Subject: PRO/AH> Equine morbillivirus - Australia: bat reservoir (08)
EQUINE MORBILLIVIRUS - AUSTRALIA: BAT RESERVOIR (08)
====================================================
From: "Nunn, Mike"
Date: Tue, 22 Oct 96 14:28:00 PDT
For people with access to the Worldwide web, Ian Douglas' information
sheet and earlier information on EMV are available in Adobe .pdf format
from:
www.dpi.qld.gov.au/ahwb/ahwbmain.htm
- ---
Mike
Dr M.J. Nunn
Principal Veterinary Officer
Bureau of Resource Sciences
P (06) 272 4036
F (09) 271 6697
[- The following gives additional information and updated background
relating to the previous posting "Equine morbillivirus - Australia (07)".
MHJ]
[Ian Douglas' internet] AUSTHORSE posting of 16 October:
Some time ago I posted material relating to the research into the
causative agent of the Acute Equine Respiratory Syndrome AERS - the
virus referred to as the equine morbillivirus (EMV).
The Queensland DPI has today released results from its search for the
virus's natural host.
I attach the text of an information sheet prepared to provide an update,
for your information.
This important research result has come from work led by Dr Peter Young,
leader of the QDPI Animal and Plant Health Service research team, based
at the Animal Research Institue, Yeerongpilly, Brisbane..
Ian Douglas
Principal Veterinary Officer
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A NEW BAT PARAMYXOVIRUS OF FLYING FOXES - LIKELY NATURAL HOSTS FOR EMV
The Animal and Plant Health Service has isolated a new bat paramyxovirus
from several flying foxes. The similarity of this virus and the virus
associated with the fatal -Acute Equine Respiratory Syndrome (AERS)-,
first described in September, 1994, suggests that the flying fox is the
natural host of AERS. This information sheet updates previous advices
concerning AERS research.
Investigations
Experimental challenge of a range of animals with EMV showed that the
disease could be reproduced artificially in cats and guinea pigs. A
survey of 500 cats from the Brisbane metropolitan area showed that none
tested positive for EMV.
A retrospective study of horse specimens submitted to veterinary
laboratories in Queensland going back as many years as possible, has
looked for cases that may have been caused by EMV but which were not
diagnosed as such at the time. No cases have been found.
Since 1994, over 5000 animals throughout Queensland, including a range
of wildlife species, have been tested for evidence of EMV. Most of
those tested were horses. In addition, horses suffering from sudden
illness or death with signs that may have been caused by EMV have been
investigated with negative results.
It seems clear that EMV infection of horses is not a usual occurrence in
this State. It may be that these two foci of infection in horses are
the only previous occurrences. An on-going watch for possible future
outbreaks will be maintained.
All testing conducted has, with the exception of flying foxes, failed to
show any evidence of EMV infection in locations or in animal species
other than those initially detected (horses and humans at Hendra and
Mackay).
Work with Flying Foxes
Animal and Plant Health Service researchers found that about 15% of
animals tested, from all four species of flying fox present in
Australia, carried antibodies to EMV.
This antibody reactivity with the equine morbillivirus confirmed that
the bats had been previously infected by a member of the Paramyxovirus
group of viruses which is the same family as that to which EMV belongs
and also suggests that the bat virus is closely related to EMV.
It was not possible, based on antibody presence alone, to establish the
degree of relatedness of the bat paramyxovirus (BPV) to the EMV virus.
To do this it was necessary to isolate BPV and compare it with EMV.
This was achieved in September 1996 when the APHS research team, working
at the Animal Research Institute, isolated a paramyxovirus from uterine
fluids from an injured female flying fox that had miscarried twin
foetuses. The Grey headed flying fox (Pteropus poliocephalus) was found
in the Brisbane area. An apparently identical virus has subsequently
been isolated from three other flying foxes.
The first virus isolated reacts strongly with human and horse serum
samples that have antibodies to EMV. Similar changes to cell cultures
are produced by BPV and EMV and the viruses appear identical on electron
microscopy. Preliminary studies have shown that the genetic sequence of
the newly isolated virus is similar to the EMV isolates. These results
demonstrate that BPV and EMV are the same virus.
Flying foxes are dispersed widely throughout the country and overseas
and are native species. As only two outbreaks of EMV infection have
been recorded it appears that spill-over of this virus to other species
is a rare event.
It is likely that flying foxes do not pose a significant risk to people.
The three human cases that are recorded all contacted the virus from
horses. Until more is known about this bat paramyxovirus it would be
advisable for those handling flying foxes to observe normal good hygiene
and care.
With this break-through achieved, our future work on the natural history
of the infection can advance. The Animal and Plant Health Service will
look to solve the final piece of the puzzle, how the virus jumped from
bat to horse on two occasions. The possibility that the seasonal
occurrence of infection may be related to breeding cycles in flying
foxes and to pregnancy in the two mares that first contacted the virus
will be researched.
....................................................................mhj