[Leish-l] Fwd: Leishmaniasis - UK: (England) dogs, 1st local cases

Wed Apr 10 09:27:38 -03 2019

LEISHMANIASIS - UK: (ENGLAND) DOGS, 1ST LOCAL CASES
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[1]
Date: Thu 4 Apr 2019
Source: EurekAlert [edited]
<https://www.eurekalert.org/pub_releases/2019-04/b-fru040319.php>

Veterinary professionals have sounded the alarm in this week's Vet
Record after treating the 1st UK case of a dog with the potentially
fatal infection leishmaniosis that is thought to have been passed on
by another dog, rather than by travel to an area where the infection
is endemic.

Canine leishmaniosis is caused by the parasite _Leishmania infantum_,
carried by the female sand fly and transmitted in its bite. It is
zoonotic, so can be passed on to people.

Dogs have been known to pick up the infection after being bitten or
wounded by another infected dog. But up to now, this has not been
reported in the UK, where cases to date have been associated with
blood transfusion, breeding programmes, or overseas travel.

But a 3-year-old neutered male shih tzu cross, which had been with its
owner since a puppy and had none of the known risk factors for
infection, was nevertheless diagnosed with leishmaniosis in
Hertfordshire.

Dog-to-dog transmission is the most likely explanation, suggest the
authors, because another dog in the household that had been imported
from Spain had to be put down 6 months earlier after developing severe
leishmaniosis.

"To the authors' knowledge, this is the 1st reported case of
leishmaniosis in the UK in a dog without a history of travel to an
endemic area," they write, adding that extra vigilance is now needed
to guard against the spread of the infection.

"In an era of increased foreign travel of dogs and increased
importation of dogs to the UK, it is likely that the number of dogs
seropositive for _L. infantum_ will continue to increase," they warn.

"Leishmania-infected dogs may present an infection risk to other dogs,
even in the absence of natural vectors, as direct transmission between
dogs is possible," they add.

A 2nd case of canine leishmaniosis in a dog with no obvious risk
factors has now also come to light in a different part of the UK [see
comment].

In a recently published letter in Vet Record, vets describe the case
of a 3-year-old fully vaccinated male neutered English pointer that
was eventually diagnosed with leishmaniosis.

The dog had never travelled outside of the UK, or beyond the borders
of Essex, where it lived. But its owners had lived in Spain and
travelled to the Jalon Valley (between Alicante and Valencia) without
their pet in the summer of 2018.

Unlike the 1st case, this dog was not living, or in regular contact
with another infected dog, and it may be that infected sand flies were
inadvertently brought back in the owners' transport, luggage, or
clothing, suggest the authors.

"However, the increased importation of infected dogs into the UK also
makes incidental socialising with infected dogs increasingly likely,"
they point out.

The case also "serves as a reminder that we should not be complacent
about the risk of _L. infantum_ establishing in the UK, even in the
current absence of the sand fly vector," they warn.

Junior Vice President of the British Veterinary Association (BVA),
Daniella Dos Santos, comments: "The increase in cases of non-endemic
diseases such as leishmaniasis is extremely concerning, with more than
a quarter of vets surveyed by BVA last year [2018] mentioning seeing
cases of this rare disease in practice.

"Leishmaniasis is mainly associated with pets who have recently
travelled outside of the UK or 'trojan' rescue dogs from abroad with
unknown health histories, which is why we have called on the
government to strengthen existing pet travel legislation and its
enforcement for the sake of animal and human health in the UK."

She advises pet owners planning on overseas travel with their dog to
seek advice from a vet before travel, while those who already own an
imported rescue dog should contact their local vet for advice on
testing and treatment for any underlying conditions.

"Anyone looking to get a dog should consider adopting from a UK
rehoming charity or welfare organisation instead of rescuing from
abroad," she recommends, "as the unintended consequences from trojan
dogs can be severe for the health and welfare of UK's pets and, in
some cases, humans too."

--
Communicated by:
ProMED-mail
<promed at promedmail.org>

[The new article, to which the above report refers, is McKenna M,
Attipa C, Tasker S, Augusto M. Leishmaniosis in a dog with no travel
history outside of the UK. Vet Record 2019;184:441
<https://veterinaryrecord.bmj.com/content/184/14/441>.

This is the 2nd Vet Record publication during 2019 dealing with canine
leishmaniasis in the UK. The previous one was a letter, published on
23 Mar in volume 184, issue 12 (Wright I, Baker S. Leishmaniosis in a
dog with no history of travel outside the UK. Vet Record
2019;184:387-8
<https://veterinaryrecord.bmj.com/content/vetrec/184/12/387.3.full.pdf>).
The affected dog had, similarly, never travelled outside of the UK, or
outside of the county of Essex. However, the owners previously lived
in Spain and travelled to the Jalon Valley without the patient in the
summer of 2018. Unlike the case addressed in the above media report,
this dog was not living with, or in regular contact with, another
infected dog. This makes the odds of direct contact with another
infected dog much lower and more likely that infection is in some way
related to the owners' foreign travel.

The grave concern raised in the UK following the 2 canine _Leishmania_
publications led the Vet Record to publish a research comment. Its
full text is included in item [2]. - Mod.AS]

******
[2]
Date: Thu 4 Apr 2019
Source: Veterinary Record [edited, references omitted]
<https://veterinaryrecord.bmj.com/content/vetrec/184/14/438.full.pdf>

Citation: Duthie MS, Petersen C. Could canine visceral leishmaniosis
take hold in the UK? Vet Record 2019;184:438-40
<http://dx.doi.org/10.1136/vr.l985>.

Canine visceral leishmaniosis (CVL) is a life-threatening outcome of
infection with _Leishmania infantum_, a protozoan parasite that is
found throughout the Mediterranean basin, the Middle East, Latin
America and some parts of Asia. Reviews of veterinary records have
indicated a CVL prevalence of between 0.007% and 0.04% in the UK. The
majority of cases have been reported in southern England, with all
affected dogs having spent at least several months in endemic
countries such as Spain.

_Leishmania_ is typically transmitted during the blood meal of
infected sand flies. However, sand flies are not found in the UK. In
the absence of sand flies, alternative routes of transmission such as
vertical, venereal and receipt of infected blood transfusions have
been demonstrated.

Additionally, it has been speculated that direct dog-to-dog
transmission through bites or wounds was the likely mode of
transmission in isolated CVL cases in Finland, Germany and New
Caledonia in the southwest Pacific.

In an article summarised on page 441 of this issue of Vet Record,
McKenna and colleagues document what they believe to be the 1st
reported case of CVL in a dog without a history of foreign travel.
Although the possibility of direct transmission of leishmaniosis
between dogs in the UK has been suggested, it has not been
conclusively shown. McKenna and colleagues concluded that
veterinarians in the UK should include CVL as a differential diagnosis
when appropriate clinical findings are present. However, the clinical
signs of CVL are quite general, so symptomology is not particularly
useful for detecting and differentiating _Leishmania_ from other
aetiologies. Even in endemic countries, discriminating the early
clinical signs of CVL can be difficult.

A unique aspect that probably aided the diagnosis of the case
described by McKenna and colleagues was prior knowledge of the
likelihood of disease; another dog in the same household had been
diagnosed with CVL 6 months before the clinical presentation of this
particular dog. Therefore, both the owners and the veterinarians had
an uncharacteristically heightened awareness of CVL as a possible
diagnosis.

This particular case presented for investigation after a 3-week period
of weight loss, intermittent vomiting, moderate pancytopenia and
diarrhoea with haematochezia. Although not reported in this case,
epistaxis is another common clinical sign that is observed in 10% to
25% of cases. The potential for exposure to infected blood or body
fluids increases as CVL advances, and this could very well have been
the mode of transmission from the index case to this particular dog.
This situation may also present a risk to owners and handlers, as _L.
infantum_ can cause disease in people.

Although the dog in the case described by McKenna and colleagues had
never been used for breeding, there would have been a risk of
transmission through sexual contact if it had. Transmission can also
occur transplacentally between a dam and her pups. This route is
believed to be the dominant source of infection within several
pedigree breeds, with genetic analyses indicating that _L. infantum_
could well have been introduced into the US foxhound population by
breeding from dogs that originated from France. Any breed of dog
originating from _Leishmania_-endemic areas could harbour the
parasite, with breeds such as briards, Neapolitan mastiffs, cane
corsos and Italian spinones indicated as at risk.

Introduction of infection through breeding could potentially lead to
sustained vertical transmission of the parasite for generations.
Another possible route of transmission is via infected blood. Canine
blood transfusions are on the rise, and over 10 000 dogs in the UK are
now registered as blood donors. To qualify as donors, dogs need to
meet certain criteria such as being in general good health and having
a normal temperature, heart rate and respiration. Among other
requirements, owners must also confirm that the dog has not been
abroad. However, because of prohibitive costs, formal testing is not
conducted for bloodborne diseases that are not prevalent in the UK.

The dog in the case described by McKenna and colleagues never received
a blood transfusion, but it could well have qualified as a donor
during the time in which it was subclinically infected (which was a
period of at least 5 months). Dogs can maintain subclinical _L.
infantum_ infection for years before progression to CVL. Therefore, it
may be prudent to expand donor exclusion criteria to include
significant contact with dogs that have spent time in
_Leishmania_-endemic regions.

Treatment with a 28-day course of 2 mg/kg miltefosine once a day
orally and 10 mg/kg allopurinol twice a day orally, and thereafter
continuation with allopurinol alone, resolved the clinical signs and
improved the body condition score in the case described by McKenna and
colleagues. Alleviation of clinical signs and a decreased parasite
load are considered indicators of treatment success in CVL patients,
although complete parasitological clearance is often not achieved.
Further control could be provided by vaccination, which has been shown
to prevent progression in non-endemic areas and would be recommended
for any dog travelling to an endemic area.

Given what we know regarding possible transmission routes, reasonable
steps to prevent _L. infantum_ from becoming established in the UK
would include screening of dogs that are imported from
_Leishmania_-endemic regions, implementing similar screening among the
contact population of any dogs presenting with CVL, regular follow-up
to ensure conversion does not occur (an important consideration given
the chronic nature of the infection and often delayed disease
presentation), exclusion of subclinically infected dogs from blood
donation, vaccination and use of topical insecticides for dogs
travelling to endemic areas.

--
Communicated by:
ProMED-mail
<promed at promedmail.org>

[Leishmaniosis is an OIE-listed zoonotic disease, warranting
reporting. For the relevant chapter 3.1.11 of the Terrestrial Manual
2018 (version adopted May 2014), please go to
<
http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/3.01.11_LEISHMANIOSIS.pdf
>.
- Mod.AS

HealthMap/ProMED-mail map:
England, United Kingdom: <http://healthmap.org/promed/p/279>]

[See Also:
2018
----
Leishmaniasis, visceral - Israel: (HZ) feline, canine
http://promedmail.org/post/20181215.6209970
Leishmaniasis - Brazil: (AL) canine, human
http://promedmail.org/post/20180905.6009156
2016
----
Leishmaniasis, canine - France
http://promedmail.org/post/20160220.4033101
Leishmaniasis - Uruguay: (SA) canine, alert
http://promedmail.org/post/20160122.3952222
2015
----
Leishmaniasis - Argentina (05): (ER) canine
http://promedmail.org/post/20151008.3701288
Leishmaniasis - Colombia: (HU) canine
http://promedmail.org/post/20150918.3653741
Leishmaniasis - Uruguay: (SA) canine, OIE
http://promedmail.org/post/20150305.3208769
2013
----
Leishmaniasis - Syria (04): comment on canine reservoir
http://promedmail.org/post/20130420.1660409
2012
----
Leishmaniasis, canine - Brazil: (MG)
http://promedmail.org/post/20121111.1404680
Leishmaniasis, human, canine - Spain (02): background
http://promedmail.org/post/20120329.1084736
Leishmaniasis, human, canine - Spain: (MD)
http://promedmail.org/post/20120328.1083656
Leishmaniasis, canine - Uruguay (02): prevention & control
http://promedmail.org/post/20120126.1022719
Leishmaniasis, canine - Singapore ex Spain: OIE
http://promedmail.org/post/20120125.1022003
Leishmaniasis, canine - Uruguay: (Montevideo) OIE
http://promedmail.org/post/20120120.1016268
2011
----
Leishmaniasis, canine - Argentina (04): (CN)
http://promedmail.org/post/20111202.3502
Leishmaniasis, canine - Argentina (03): (CN)
http://promedmail.org/post/20110925.2916
Leishmaniasis, canine - Argentina (02): (CN)
http://promedmail.org/post/20110625.1943
Leishmaniasis, canine - Argentina: (CN)
http://promedmail.org/post/20110323.0908
2010
----
Leishmaniasis, human, canine - Paraguay
http://promedmail.org/post/20100813.2784
Leishmaniasis, canine - Argentina: (CN)
http://promedmail.org/post/20100211.0483
2009
----
Leishmaniasis, canine - Argentina: (SF)
http://promedmail.org/post/20091107.3859
Leishmaniasis, visceral - Brazil: (MT), human, canine
http://promedmail.org/post/20090123.0290
2008
----
Leishmaniasis, visceral - Brazil (03): (DF), human, canine
http://promedmail.org/post/20081130.3766]
.................................................sb/arn/rd/mpp
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