seal parvovirus
DESCRIPTION
clinical and molecular epidemiology of seal parvovirus infectionTRANSCRIPT
Clinical and molecular epidemiology of seal parvovirus infection in seals
of Northwestern Europe
Rebriarina HapsariProf. dr. A.D.M.E Osterhaus, DVM (supervisor)
R. Bodewes, Ph.D, DVM (supervisor)
A novel parvovirus was found in the brain tissue of a harbor seal
Bodewes, et al. PLOS One, 2013
A novel parvovirus was found in the brain tissue of a harbor seal
Erythroparvoviruses
AsymptomaticErythema infectiosum
Arthritis
Fetal hydropsHealthy
???
AnemiaIn non-human
primates
Aplastic crisis
CNS disease
???
Our hypotheses: Seal parvovirus…
has been circulating among seals for at least 10 years
gives clinical manifestations of anemia or low red blood cell count in seals
has an evolutionary pattern similar to other parvoviruses
*PDV epizootic years in North-Western Europe
Seal sera (2002-2014)
Seal spleen tissues (1988*, 2002*, 1989-2001)
Seal parvovirus screening and herpesvirus detection
Genome sequencing and phylogenetic analysis
LIPS assay development
Clinical, hematological, and pathological description
Samples Molecular Analysis Clinical picture analysis
Low prevalence of seal parvovirus in sera samples
2002
2003
2004
2005
2006
2007
2008
2009
2011
2012
2013
2014
0
4
8
12
16
20
Harbor seals (PV) n=131Grey seals (HG) n=69
Year
Num
ber o
f se
al s
era
test
ed
Prevalence of 0.5%
*
*
*
Prevalence of 8%
Seal parvovirus was more prevalent in seal spleen tissue samples
Table overview of clinical parameters and pathological diagnoses
Sample ID Sex Age Sample
Co-infection with Pathological diagnoses and/or
major clinical signs PDV PhHV-1
PV880823.6 NI NI spleen NI - NI
PV880927.20 NI NI spleen NI - NI
HG020628.02 F (sub)adult spleen - - Acute non-infectious cause of dead (possible drowning)
PV020628.13 M (sub)adult spleen - + Intestinal volvulus
PV020718.12 F juvenile spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.08 F (sub)adult spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.09 M (sub)adult spleen + - Extensive, acute, severe, interstitial pneumonia
PV020919.03 F (sub)adult spleen + -Euthanized due to presence of severe neurological
signs, PDV detected in the brain
PV021004.1 M (sub)adult spleen - -Emaciation; diffuse, subacute, marked, purulent
bronchopneumonia
HG06-130 F juvenile serum - -Several wounds on flippers and skin lesions suggestive
of pox virus infection
PV12-410* M juvenile serum and spleen - - Chronic, mild, non-suppurative meningo-encephalitis
PV121216.01* F juvenile spleen - +Acute, moderate necrotizing bronchitis and bronchiolitis
and acute interstitial pneumonia
Table overview of clinical parameters and pathological diagnoses
Sample ID Sex Age Sample
Co-infection with Pathological diagnoses and/or
major clinical signs PDV PhHV-1
PV880823.6 NI NI spleen NI - NI
PV880927.20 NI NI spleen NI - NI
HG020628.02 F (sub)adult spleen - - Acute non-infectious cause of dead (possible drowning)
PV020628.13 M (sub)adult spleen - + Intestinal volvulus
PV020718.12 F juvenile spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.08 F (sub)adult spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.09 M (sub)adult spleen + - Extensive, acute, severe, interstitial pneumonia
PV020919.03 F (sub)adult spleen + -Euthanized due to presence of severe neurological
signs, PDV detected in the brain
PV021004.1 M (sub)adult spleen - -Emaciation; diffuse, subacute, marked, purulent
bronchopneumonia
HG06-130 F juvenile serum - -Several wounds on flippers and skin lesions suggestive
of pox virus infection
PV12-410* M juvenile serum and spleen - - Chronic, mild, non-suppurative meningo-encephalitis
PV121216.01* F juvenile spleen - +Acute, moderate necrotizing bronchitis and bronchiolitis
and acute interstitial pneumonia
Table overview of clinical parameters and pathological diagnoses
Sample ID Sex Age Sample
Co-infection with Pathological diagnoses and/or
major clinical signs PDV PhHV-1
PV880823.6 NI NI spleen NI - NI
PV880927.20 NI NI spleen NI - NI
HG020628.02 F (sub)adult spleen - - Acute non-infectious cause of dead (possible drowning)
PV020628.13 M (sub)adult spleen - + Intestinal volvulus
PV020718.12 F juvenile spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.08 F (sub)adult spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.09 M (sub)adult spleen + - Extensive, acute, severe, interstitial pneumonia
PV020919.03 F (sub)adult spleen + -Euthanized due to presence of severe neurological
signs, PDV detected in the brain
PV021004.1 M (sub)adult spleen - -Emaciation; diffuse, subacute, marked, purulent
bronchopneumonia
HG06-130 F juvenile serum - -Several wounds on flippers and skin lesions suggestive
of pox virus infection
PV12-410* M juvenile serum and spleen - - Chronic, mild, non-suppurative meningo-encephalitis
PV121216.01* F juvenile spleen - +Acute, moderate necrotizing bronchitis and bronchiolitis
and acute interstitial pneumonia
Table overview of clinical parameters and pathological diagnoses
Sample ID Sex Age Sample
Co-infection with Pathological diagnoses and/or
major clinical signs PDV PhHV-1
PV880823.6 NI NI spleen NI - NI
PV880927.20 NI NI spleen NI - NI
HG020628.02 F (sub)adult spleen - - Acute non-infectious cause of dead (possible drowning)
PV020628.13 M (sub)adult spleen - + Intestinal volvulus
PV020718.12 F juvenile spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.08 F (sub)adult spleen + + Extensive, acute, severe, interstitial pneumonia
PV020719.09 M (sub)adult spleen + - Extensive, acute, severe, interstitial pneumonia
PV020919.03 F (sub)adult spleen + -Euthanized due to presence of severe neurological
signs, PDV detected in the brain
PV021004.1 M (sub)adult spleen - -Emaciation; diffuse, subacute, marked, purulent
bronchopneumonia
HG06-130 F juvenile serum - -Several wounds on flippers and skin lesions suggestive
of pox virus infection
PV12-410* M juvenile serum and spleen - - Chronic, mild, non-suppurative meningo-encephalitis
PV121216.01* F juvenile spleen - +Acute, moderate necrotizing bronchitis and bronchiolitis
and acute interstitial pneumonia
SePV from 1988-2012 displayed only one amino acid change in 1 most recent variant
12 (1.3%) variant nt positions in partial NS
13 (0.76%) variant nt positions in VP2, 1 amino acid change (S540T)
P. Norja, et.al. 2008
Seal parvovirus showed high substitution rate per site per year
Estimated nt substitution rate:
Partial NS = 2.00x10-4/site/year(HPD, 1.36x10-5-4.04x10-4)
VP2 = 1.15x10-4/site/year(HPD, 1.43x10-5-2.22x10-4)dN/dS=0.33
Discussion
Seal parvovirus has been circulating for more than 24 years among seals of Northwestern Europe
Low prevalence of 0.5% in the serum and 8% in the spleen tissue Relatively higher in PDV outbreak 2002 Seroprevalence?? LIPS assay hasn’t worked well
Low red blood cell count (RBC) was seen in two cases No more additional positive cases in a group of seals with low RBC
at admission
Neurological signs were in at least two cases Co-infection with PDV and/or PhHV-1, the spectrum of clinical
signs associated with SePV infection remained unclear
Discussion
Seal parvovirus has a high nucleotide substitution rates Similar to other parvoviruses, eg. B19, canine parvovirus type 2,
human bocavirus, etc. Only one amino acid change in the latest variant available from
2012 (S540T) strong negative selection
Minimal sequence variations of seal parvovirus found in harbor seal and grey seal
Similar to herpesviruses among phocids; and parapoxvirus in two species of pinnipeds
Metapopulation serves as single reservoir for the virus
Conclusions
Seal Parvovirus…
has been circulating in both harbor and grey seals since at least 1988
could not be attributed to any specific clinical manifestation
showed similar substitution rate to other parvoviruses but with a strong negative selection
Acknowledgments
Marco W.G. van de Bildt Thijs KuikenBart Haagmans
(virus discovery group)Miranda de Graaf Rogier Bodewes ADME Osterhaus
Ana Rubio GarciaGuillermo J. Sanchez-Contreras
Frank van VlietJan Nouwen
Submitted to PLoSONE on 14 August 2014
Our LIPS assay showed inconsistent results and high LU for the blank
The use of fresh antigen didn’t change the results
Buffers used in the assay did matter