Ebola Virus Infection in Dogs and Pigs

Ebola Virus Infection in Dogs and Pigs

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Description: Ebola Virus Antibody Prevalence in Dogs and Human Risk: Serologic survey of dogs in highly infected areas during 2001-2002 Ebola Zaire outbreak in Gabon. Symptoms were not observed in any of these dogs. Blood samples were negative by PCR.

“Although dogs can be asymptomatically infected, they may excrete infectious viral particles in urine feces and saliva for a short period before virus clearance, as observed experimentally in other animals.” Discovery of Swine as a Host for the Reston ebolavirus: Swine serum and tissue samples from Philippines submitted to FADDL in 2008 . Highly pathogenic PRRS virus and PCV2 isolated . Cytopathic virus also isolated in VERO cells (non-permissive to PRRSV) .

Microarray revealed Reston Ebola . Reston Ebola was found only in samples also positive for PRRSV . Genomes of three virus isolates were significantly divergent from each other, suggesting that they have been circulating for several years .

Ebola Reston Virus Infection of Pigs: Clinical Significance and Transmission Potential: Experimental challenge with REBOV in 16 five week old pigs . Replication of virus in internal organs and viral shedding from nasopharynx and feces in absence of clinical signs . Virus present in skeletal muscle .

Concurrent respiratory infection may facilitate transmission . “...asymptomatic infection of pigs with REBOV occurs ..animals so affected pose a transmission risk to farm, veterinary, and abattoir workers.” .

 
Author: James A. Roth DVM PhD (Fellow) | Visits: 2408 | Page Views: 2518
Domain:  Medicine Category: Veterinary Subcategory: Infectious Diseases 
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Contents:
10/18/2014

Ebola Virus Infection
in Dogs and Pigs
James A. Roth, DVM, PhD
Center for Food Security and Public
Health
College of Veterinary Medicine
Iowa State University

Five Species of Ebola Viruses
Enveloped RNA virus related to
Marburg virus
• Genus: Ebolavirus (5 species)


− Pathogenic





for humans (Africa)

Zaire ebolavirus (ZEBOV)
Sudan ebolavirus
Tai forest ebolavirus
Bundibugyo ebolavirus

− Not

pathogenic for humans; pathogenic
for non-human primates (Philippines,
China)


Reston ebolavirus (REBOV)
Center for Food Security and Public Health
Iowa State University - 2014

1

10/18/2014

Ebola Virus Antibody Prevalence in
Dogs and Human Risk
Allela et al. Emerg. Infect. Dis. 11:385-390, 2005

Serologic survey of dogs in highly
infected areas during 2001-2002
Ebola Zaire outbreak in Gabon
• IgG ELISA


− 159

dogs in epidemic area – 25.2%
positive
− 66 dogs in villages with human cases
and animal source – 31.8% positive
− 102 dogs in France – 2% positive (false)
Center for Food Security and Public Health
Iowa State University - 2014

Ebola Virus Antibody Prevalence in
Dogs and Human Risk
Allela et al. Emerg. Infect. Dis. 11:385-390, 2005





Symptoms were not observed in any of
these dogs
Blood samples were negative by PCR
“Although dogs can be asymptomatically
infected, they may excrete infectious viral
particles in urine feces and saliva for a
short period before virus clearance, as
observed experimentally in other animals.”
Center for Food Security and Public Health
Iowa State University - 2014

2

10/18/2014

CDC Website: Questions and
Answers about Ebola and Pets


CDC Website:
http://www.cdc.gov/vhf/ebola/trans
mission/qas-pets.html



“CDC is currently working with the
USDA, the AVMA, and many other
partners to develop additional
guidance for the U.S. pet population”
Center for Food Security and Public Health
Iowa State University - 2014

Discovery of Swine as a Host for the
Reston ebolavirus
Barrette et al, Science 325:204-206, 2009
PIADC, CDC and Philippines BIA



Swine serum and tissue samples from
Philippines submitted to FADDL in 2008



Highly pathogenic PRRS virus and PCV2
isolated



Cytopathic virus also isolated in VERO cells
(non-permissive to PRRSV)



Microarray revealed Reston Ebola

Center for Food Security and Public Health
Iowa State University - 2014

3

10/18/2014

Discovery of Swine as a Host for the
Reston ebolavirus
Barrette et al, Science 325:204-206, 2009
PIADC, CDC and Philippines BIA



Reston Ebola was found only in
samples also positive for PRRSV



Genomes of three virus isolates were
significantly divergent from each
other, suggesting that they have
been circulating for several years
Center for Food Security and Public Health
Iowa State University - 2014

Discovery of Swine as a Host for the
Reston ebolavirus
Barrette et al, Science 325:204-206, 2009
PIADC, CDC and Philippines BIA



Six (of 141) serum samples of
people working with pigs in
Phillipines had antibody to REBOV



No evidence of disease in humans

Center for Food Security and Public Health
Iowa State University - 2014

4

10/18/2014

A Seroepidemiologic Study of Reston
ebolavirus in Swine in the Phillipines
(Sayama et al, BMC Vet Res 2012; 8:82)
Japan and Phillipines



215 swine sera from two REBOV affected farms in
2008




~70% positive for REBOV antibodies by
multiple serodiagnostic systems

98 swine sera from non-epizootic region


All negative

Center for Food Security and Public Health
Iowa State University - 2014

Ebola Reston Virus Infection of Pigs: Clinical
Significance and Transmission Potential
(Marsh et al, JID 2011:204 S804-S809)
Australian Animal Health Laboratory and CDC



Experimental challenge with REBOV in 16 five
week old pigs



Replication of virus in internal organs and viral
shedding from nasopharynx and feces in absence
of clinical signs



Virus present in skeletal muscle



Virus clearance associated with seroconversion
occurring within 10 to 12 days after challenge –
no virus persistence
Center for Food Security and Public Health
Iowa State University - 2014

5

10/18/2014

Ebola Reston Virus Infection of Pigs: Clinical
Significance and Transmission Potential
(Marsh et al, JID 2011:204 S804-S809)
Australian Animal Health Laboratory and CDC



Concurrent respiratory infection may facilitate
transmission



“…asymptomatic infection of pigs with REBOV
occurs … animals so affected pose a transmission
risk to farm, veterinary, and abattoir workers.”

Center for Food Security and Public Health
Iowa State University - 2014

Reston Virus in Domestic Pigs in China
(Pan et al, Arch Virol 2014;159:1129-1132)
Peoples Republic of China



137 spleen samples from pigs that died of PRRSV
on 3 farms in Shanghai



4/137 positive for Reston ebolavirus by RT-PCR



All co-infected with PRRSV and under 8 weeks old



One sequence was most closely related to
Philippines REBOV, other 3 more distantly related
to Philippines REBOV and to each other
Center for Food Security and Public Health
Iowa State University - 2014

6

10/18/2014

Replication, Pathogenicity, Shedding, and
Transmission of Zaire ebolavirus in Pigs
(Kobinger et al, JID 2011:204:200-208)
CFIA and others, Winnipeg, Canada



Demonstrated that pigs (3 to 5 weeks old) are susceptible
to mucosal challenge with ZEBOV and can develop severe
respiratory disease which is transmitted to pen mates
(more severe in older pigs)



Virus replicated in macrophages, pneumocytes and
endothelial cells of lung



“In contrast to the severe systemic syndrome often leading
to shock and death in primates, pigs developed a
respiratory syndrome that could be mistaken for other
porcine respiratory diseases.”

Center for Food Security and Public Health
Iowa State University - 2014

Transmission of Ebola virus from pigs to
non-human primates
(Weingartl et al, Sci Rep 2012;2:811-)
CFIA and others, Winnipeg, Canada



Oronasal challenge of six 4 week old pigs with
Zaire ebolavirus. Four Macaques in same room,
no direct contact



Increase in respiratory rate and in rectal
temperatures of pigs was observed between 5
and 7 days post infection. All piglets apparently
recovered from the disease by 9 dpi.

Center for Food Security and Public Health
Iowa State University - 2014

7

10/18/2014

Transmission of Ebola virus from pigs to
non-human primates
(Weingartl et al, Sci Rep 2012;2:811-)
CFIA and others, Winnipeg, Canada



Zaire ebolavirus was transmitted from pigs to all
four cynomolgus macaques without direct contact



Transmission between macaques in similar
housing conditions was never observed



Design and size of the animal cubicle did not
allow to distinguish whether the transmission was
by aerosol, small or large droplets in the air, or
droplets created during floor cleaning

Center for Food Security and Public Health
Iowa State University - 2014

Immunopathogenesis of Severe Acute Respiratory
Disease in Zaire ebolavirus-Infected Pigs
(Nfon et al. PLoS ONE 8(4): e61904)
CFIA and others, Winnipeg, Canada



May be important age differences: 4 week old
piglets had mild to moderate clinical signs while 6
week old piglets had rather severe respiratory
distress



“Genes for proinflammatory cytokines,
chemokines and acute phase proteins, known to
attract immune cells to sites of infection, were
upregulated in the lungs, causing the heavy
influx of cells into this site.”


Age difference may be related to innate immune ability
to generate a cytokine storm
Center for Food Security and Public Health
Iowa State University - 2014

8

10/18/2014

Vaccines and Diagnostics for
Transboundary Animal Diseases
J. A. Roth, J. A. Richt, I. Morozov, (eds) Developments in
Biologicals. 2013. Vol 135, 226 pages.


Workshop, Ames, Iowa, September 17-19, 2012




Funded by Department of Homeland Security, Science
and Technology Directorate

Review of Ebola Virus Infections in Domestic
Animals
(Weingartl et al, Dev Biol 135:211-218, 2013)



Ebola: Facing a New Transboundary Animal
Disease
(Feldmann et al, Dev Biol 2013; 135:201-209)




Diagnostics
Vaccines
Center for Food Security and Public Health
Iowa State University - 2014

Additional Information
• Updated CFSPH Fact Sheet: Ebolavirus and
Marburg Virus Infections (111 references)

− http://www.cfsph.iastate.edu/Factsheets/pdfs/viral_he
morrhagic_fever_filovirus.pdf

• OIE Terrestrial Animal Health Code
−No information on Ebola

Center for Food Security and Public Health
Iowa State University - 2014

9

10/18/2014

Association of Reston ebolavirus with
Arterivirus infection


Discovery of Reston ebolavirus in
Macaques in Reston, VA 1989
Co-infected with simian hemorrhagic fever
virus
− Arteriviridae genus Arterivirus




Reston ebolavirus in Philippines and China
All pigs were co-infected with Porcine
Reproductive and Respiratory Syndrome Virus
− Arteriviridae genus Arterivirus


Center for Food Security and Public Health
Iowa State University - 2014

Factors to Consider


Ebola viruses are
Biosafety Level 4 Select
Agents (including REBOV
which is non-pathogenic
for humans or swine)



Greatly restricts ability to
conduct animal studies



Diagnostic testing in BL2
laboratories?
Center for Food Security and Public Health
Iowa State University - 2014

10

10/18/2014

Factors to Consider


Where can diagnostic samples be
submitted from domestic animals for
Ebola serology, PCR, virus isolation?
− CDC

or NIH labs?

− NVSL

or NAHLN labs?

− Validation

animals?

of assays for use in domestic
Center for Food Security and Public Health
Iowa State University - 2014

Factors to Consider


Dogs vs. commercial swine vs.
backyard swine vs. feral swine?
− Personal

protective equipment?

− Euthanasia?
− Carcass

disposal?

− Feces/Manure

disposal?
Center for Food Security and Public Health
Iowa State University - 2014

11

10/18/2014

Factors to Consider


Ebola Zaire vs. Ebola Reston?



Ebola Reston has apparently been
circulating in the Philippines and in
China for several years with no
evidence of health impacts on
humans

Center for Food Security and Public Health
Iowa State University - 2014

Communication Points


Being developed by CDC, USDA,
AVMA and others

Center for Food Security and Public Health
Iowa State University - 2014

12

10/18/2014

CDC Website: Questions and
Answers about Ebola-Reston
Virus in Pigs, Philippines


CDC Website:
http://www.cdc.gov/ncidod/dvrd/spb
/outbreaks/qaEbolaRestonPhilippines
.htm

Center for Food Security and Public Health
Iowa State University - 2014

Questions, Comments: jaroth@iastate.edu

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