Download Dromedaries as possible reservoir of some infectious diseases

Dromedaries as possible reservoir of
some infectious diseases: the case of
Brucellosis…and other viruses!
Giovanni Savini
Abu Dhabi February 15th 2016
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Our international expertise
My presentation
 Brief Introduction to camelids
and related problems
 Most important infectious
disease of camelids at the
animal/human interface
(Rabies, Camelpox, Brucellosis)
 Our experience at the IZSAM
with camelids (BTV, RVF, WNV)
and our future goals
COMMON ORIGIN 60 millions years ago
Evolution
NEW WORLD CAMELS
OLD WORLD CAMELS
Economic impact
 New world camels are very popular in
Europe and US
 325.000 camelids (llama and alpaca)
are present in the US
 Are camelids susceptible to the wide
range of viruses affecting large and
small ruminants?
Economic impact
Pathogenic Viral Infections
Rabies, Borna, Camelpox,
Parapox, Papillomatosis, FMD,
VS, PPR, RFV, BVD, BT, WND,
EEE, Rota/Corona (Diarrhoea),
BoHV-1, EHV, Flu A, Equine
rhinovirus abortion
Non-Pathogenic Viral
Infections
Rinderpest, AHS, Respiratory
viruses, Retrovirus infections
Antibodies for many viral agents were
detected
Antibodies for many viral agents were
detected
In general camelids are relatively free of diseases
RABIES
Source:
Feral Dogs. Transmission from alpaca to
alpaca by bites has been described
Incubation
NWCs: 15 days-3 months
OWCs: 3 weeks to 6 months
Death
6 to 8 days after clinical signs
RABIES
Clinical signs
in OWCs:
• Raging Fury for 1 or 3 days (male
dromedary) followed by paralytic stage
(attempt to yawn)
• Silent Fury, generally seldom seen in
camels
During Raging Fury: restless, aggression,
selfmutilations biting and snapping,
hypersalivation
in NWCs:
Pica, aggressive form, attacks on people
pen mates and offspring.
(No spit).
Brucellosis
 OWCs: frequently infected with
brucellosis
 NWCs: rare but described
 Zoonosis: 500,000 new cases
annually, 30% of camel handlers
and 2% of Laboratory workers
 Infection: contact with infected
material, unpasteurized milk
and dairy products,
uncontrolled trade, airborne
transmission
Brucellosis
 Infection is related to the
presence of sheep and cattle
 Placentas and aborted foetuses
are the most infected tissues
 Milk excretion seems to be
intermittent in camels
 Brucella is very resistent even if
it prefers cool temperature it
can survive also in hot desert
environment.
Brucellosis
B. melitensis and B. abortus the
most serious and the most common
 B. melitensis is common in
camels in ME and Africa (biovars
1, 2, 3 and 6)
 B. abortus in the former URSS
Incubation period 60 dd
Brucellosis




Abortions (1° pregnancy)
Stillborn calves
Reduced milk
Retained placenta has
been never described
 Orchitis
Brucellosis
Diagnosis in the field can
be difficult because of
other causes of abortions:
 Salmonellosis
 Trypanosomosis
 Campylobacter spp.
infection
 Trichomonas foetus
Brucellosis
Molecular and culturing are the
preferred test methods whereas
multiple serological tests are needed for
identification of all reactors
Serological assays:





CFT (longer reaction)
RBT
SAT (BPAT ecc…) (IgM and IgG)
FPA (promising)
ELISA
 ELISA on milk is also possible
(modified MRT)
Brucellosis
Serology only can be
confusing (false positive by
Y. enterocolitica)
The combination of multiple tests
is CRUCIAL (real time and
serological tests, 99% sensitivity)
None of the serological tests
are validated for camel
(human)
There is a need for a standardization of
assays!!!!
Brucellosis
Antibiotic treatments are long and
difficult and with doubtful results
Vaccination
more doubts than certainties
Brucella abortus S19 vaccines
Brucella melitensis Rev1
 No challenge after vaccination
 Best age for vaccination
 Reduced dose, immunity lasts
3-4 months
Bluetongue
BTV (1-27)
EHDV
(1-7)?
AHSV (1-8)
BTV-26/27
BTV-26, direct transmission
New Serotypes
BTV-28
Middle East
BTV-29
South Africa
Incursioni del virus della BT nel bacino del
Mediterraneo
•
Figure 1: Main transhumance routes (in red) of small ruminants and camels across
Morocco
Serosurveillance in Mauritania
N=159
N=119
58% of cattle positive for
BTV by c-ELISA
47 animals had BTV 26
neutralising Abs
68% of dromedaries
positive for BTV by c-ELISA
99 animals had BTV 26
neutralising Abs
Surveillance in Mauritania
N=119
N=159
20 pos 1/27
20 neg 1/24
5 pos 1/27
5 neg 1/24
LOW TITRES
LOW TITRES
rt RT-PCR detecting 1/27 serotypes
Surveillance in Mauritania
BTV-26, Kuwait 2010
• One single isolate
• Used for animal work
• Very low titres in goats
and sheep
Surveillance in Mauritania
BTV-26 infected samples from Mauritania
were not recognized as BTV-26 bt serotype specific rtRT-PCR
•
•
•
•
•
Divergent BTV-26 circulating in Africa?
Novel serotype in Africa
NGS did not help (low titres)
Small piece of genomic information
Poor quality of samples
Surveillance in Mauritania
……. however, considering the serological results
and that...
 Some samples were
positive by ELISA and by rt
RT-PCR, negative by SN
 Recent infections at the
slaughterhouse (animals
gathered together up to 10
days)
 Direct transmission
Origin
BTV-26
Evolution
BTV-4 2012: Sardinia
1
5
10
BTV-1 SAD2012
86% of confirmed cases
BTV-4 SAD2012
13% of confirmed cases
BTV-4 2014: Balkan Countries
and Italy
BTV-1, BTV-2, BTV-4, BTV-16 and BTV-24
BTV-4 APU2014
BTV-4 2014: Morocco and
Spain
BTV-2, BTV-3, BTV-4, BTV-16
16
4
2
4
3
4
4
2
16
4
16
4
2
4
3
4
4
2
16
4
Morocco/1-2014
Morocco/2-2014
Potential evolution of BTV
BTV1/8 Vector
Borne strain
BTV-26/27
Direct contact
1
5
10
1
X
5
10
BTV-1 or BTV-8 Direct contact?
BTV-26 in Mauritania
Surveillance in Mauritania
In the framework of scientific
collaboration between CNERV of
Nouakchott-Mauritania and
IZSA&M of Teramo-Italy, 157
bovine blood samples and 119
blood samples from camels
collected at the Nouakchott
abattoir in March 2013, have been
tested by molecular tests for
different pathogens , considered
to be likely present or at risk in the
Country
Surveillance in Mauritania
Pathogens & tests
Dromedaries
Bovines
SERA
• AHSV => c-ELISA
• EHDV => c-ELISA
• RVFV => IgG, c-ELISA
• RVFV => qRT-PCR
• PPRV => c-ELISA
• WNV => c-ELISA
• WNV => SN
SERA
• RVF => IgG, c-ELISA
• RVF => qRT-PCR
• PPRV => c-ELISA
• PPRV => SN
BLOOD
• BTV => qRT-PCRs
• VI
BLOOD
• BTV => qRT-PCRs
• VI
Surveillance in Mauritania
Vector transmitted bacterial and parasitic pathogens
Cattle
Positives (percentage)
Tested
Trypanozoon subgenus
Theileria annulata-Real time E. ruminantium-traditional
(T. brucei, T. evansi and T PCR
PCR
equiperdum)-Realtime
PCR
119
0
114 (96%)
0
Camels
Positives (percentage)
Tested
Trypanozoon subgenusReal time PCR-Confirmed
by Variable Surface
Glycoprotein RoTat 1.2
PCR specific for T.evansi
Theileria annulata-Realtime
PCR
E. ruminantium-traditional
PCR
157
8 (5.10%)
0
0
Surveillance in Mauritania
Virological results
Camelidae
AHS
EHDV WND WND
c-Elisa c-Elisa c-Elisa SN
PPR
c-ELISA
RVF IgG RVF
c-ELISA RT-PCR
Pos
5
63*
146
41
0
72
0
Doubt
1
2
1
3
0
4
0
Neg
153
21
12
70
159
83
159
Tested
159
86
159
138
159
159
159
* Typing pending
** 24 samples were toxic for cells
**
PPRV
 Camelids are susceptible
to the infection
 They could play an
important role by
disseminating the
infection (to goats)
 Clinical signs may be
different: fever, nasal
discharge but also sudden
death, diarrhoea, abortion
RVFV
•
•
•
•
•
Brief period of viraemia
Abortion is the only sign of infection
No data on calves
No data on Bactrian camels
Described (?) in Saudi Arabia in 2000
and in Kenya in 2006 but the virus was
never isolated
• An attenuated vaccine exists (strain MP22) for dromedaries.
• Good humoral response but challenge
was not performed
Zoonosis
Surveillance in Mauritania
Virological results
Camelidae
AHS
EHDV WND WND
c-Elisa c-Elisa c-Elisa SN
PPR
c-ELISA
RVF IgG RVF
c-ELISA RT-PCR
Pos
5
63*
146
41
0
72
0
Doubt
1
2
1
3
0
4
0
Neg
153
21
12
70
159
83
159
Tested
159
86
159
138
159
159
159
* Typing pending
** 24 samples were toxic for cells
**
WND
Number of positive
Neutralizing antibodies for WNV
5
10
20
40
80
160
320
Titre
NWCs get infected with WNV but in general the role of
camelids needs to be investigated
Surveillance in Mauritania
Virological results
Camelidae
AHS
EHDV WND WND
c-Elisa c-Elisa c-Elisa SN
PPR
c-ELISA
RVF IgG RVF
c-ELISA RT-PCR
Pos
5
63*
146
41
0
72
0
Doubt
1
2
1
3
0
4
0
Neg
153
21
12
70
159
83
159
Tested
159
86
159
138
159
159
159
* Typing pending
** 24 samples were toxic for cells
**
Surveillance in Morocco
Orbivirus Serosurveillance
% Seropositive
Year
2003
2009
2010
2011
2012
BTV
11%
25,59%
34,93%
26,87%
59,71%
AHSV
1,28%
1,07%
1,20%
0,00%
1,07%
EHDV
0,00%
0,00%
0,00%
0,00%
0,00%
Virus
Future Goals at IZSAM
• Role of camelids as
BTV and EHDV
reservoir
• Role of camelids in
the biological cycle
of flaviviruses (Zika?)
• Validation of
serological assays for
camelids
Conclusion
Pragmatic attitudes should be adopted to imagine and
implement new strategies. In front of new challenges
experience and conservative thoughts might not be
the optimal solution
‫شكرا الهتمامكم‬