Veterinary Diagnostic Laboratory Iowa State University Emerging Coronaviruses in US Swine “Diagnostic Lab Update” RB Baker, R Main, & K Mueller Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Lab, Iowa State University, Ames, IA 50011
Emerging Coronaviruses in US Swine “Diagnostic Lab Update” RB Baker, R Main, & K Mueller Department of Veterinary Diagnostic and Production Animal Medicine , Veterinary Diagnostic Lab, Iowa State University, Ames, IA 50011. Faculty, Staff, & Students of ISU VDL. - PowerPoint PPT Presentation
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Veterinary Diagnostic LaboratoryIowa State University
Emerging Coronaviruses in US Swine“Diagnostic Lab Update”
RB Baker, R Main, & K Mueller
Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Lab, Iowa State University, Ames, IA 50011
Veterinary Diagnostic LaboratoryIowa State University
• Limited correlation between IFA titer and protective immunity• IFA antibody duration is short• Difficult to correlate IFA titer with success of feedback
Dr. Kyoung-Jin Yoon, ISU-VDLDr. John Johnson, ISU-VDL
Veterinary Diagnostic LaboratoryIowa State University
Yoon, Madson, Magstad, Labois, et al – experimentally infected with PEDV.
Veterinary Diagnostic LaboratoryIowa State University
identities to PEDV strains identified in US swine since April 2013
– 5 cases shared 99.6-100% nucleotide identities to each other but only 93.4-94.6% nucleotide identities to the originally identified US strain
Veterinary Diagnostic LaboratoryIowa State University
PEDV Variant: Epidemiology• January 2014 – ISU VDL retrospective testing
– 183 random PEDV PCR positive fecal samples from ISU VDL cases submitted May to September 2013
– 6 of 183 cases were positive “PEDV variant” – Five of the 6 PEDV variant positive cases were submitted in May 2013
and the other in early June
• In retrospect, both PEDV strains have been present and circulating in US since April/May 2013.– Earliest PEDV positive case identified in the US was submitted to the
ISU VDL on April 15, 2013.
Veterinary Diagnostic LaboratoryIowa State University
PDCoV• PDCoV not PEDV or TGEV or PRCV
– Delta vs. Alpha Coronaviruses– Doesn’t appear to be any cross-protection
• Vomiting and diarrhea (Field/Diagnostic Reports)
– Similar clinical signs and lesions to PEDV/TGE– Reportedly more transient &/or less severe – Koch’s postulates yet to be fulfilled
• ISU-VDL Available Assays– PDCV PCR is currently offered– PDCV sequencing becoming available
• Limited retrospective testing on PDCoV completed to date
Alphacoronavirus: PEDV
Deltacoronavirus: PDCV
Veterinary Diagnostic LaboratoryIowa State University
0
2
4
6
8
10
12
14
16
18
Positive PDCoV Cases @ ISU VDL per Week by Farm Type
Unknown
Grow-Finish
Sow
Date by Week
# PD
CoV
Posi
tive
Case
s
2-17-14Began PDCV PCR
Testing at ISU VDL
Veterinary Diagnostic LaboratoryIowa State University
22-D
ec
29-D
ec
5-Ja
n
12-Ja
n
19-Ja
n
26-Ja
n
2-Fe
b
9-Fe
b
16-F
eb
23-F
eb
2-M
ar
9-M
ar
16-M
ar
0
10
20
30
40
50
60
70
80Cumulative Positive PDCoV Cases by Farm Type
UnknownGrow-FinishSow
Date by Week
# PD
CoV
Posi
tive
Case
s
2-17-14Began PDCV PCR
Testing at ISU VDL
Veterinary Diagnostic LaboratoryIowa State University
ISU VDL PDCoV Positive Swine CasesWeek Received
@ VDL Total # PCR
Positive Cases
Farm State
IA IL IN MI MN MO NC NE OH OK PA ? 12/22/13 1 1
12/29/13
1/5/14
1/12/14
1/19/14 2 1 1
1/26/14
2/2/14 2 1 1
2/9/14 6 4 1 1
2/16/14 10 6 1 1 1 1
2/23/14 12 2 1 5 1 1 1 1
3/2/14 14 1 5 1 3 1 1 1
3/9/14 17 8 1 1 1 3 1 1 1
3/16/14 8 3 1 3 1
Total 71 26 10 7 1 3 9 4 3 3 1 3 1
**totals include biological samples only--no environmental or feed samples are included in the this data
Veterinary Diagnostic LaboratoryIowa State University
Emerging Coronaviruses in US Swine“Diagnostic Lab Update”