hse-phl-dublin increased prevalence and diversity of vtec in ireland: fact of artifact? dr anne...
TRANSCRIPT
HSE-PHL-Dublin
Increased Prevalence and diversity of VTEC
in Ireland: Fact of Artifact?
Dr Anne Carroll
Dr Eleanor McNamara
HSE-PHL-Dublin
PHL Scope
Official testing laboratory, Food and water (S.I. 85 of 1998 and S.I. 117 of 2010) .
Accredited ISO 17025 National VTEC diagnostic and typing service
(Clinical, foods water environmental) Clinical diagnostic general microbiology
service, hospital/GP
HSE-PHL-Dublin
National VTEC Service Stools, Food, Water. Isolate Confirmation Accredited PCR >22,000 tests PFGE
VTEC Reference Service
HSE-PHL-Dublin
VTEC incidence
0
1
2
3
4
5
6
7
Year 2002 Year 2003 Year 2004 Year 2005 Year 2006 Year 2007 Year 2008 Year 2009 Year 2010 Year 2011
Incidence/100000
Total
O157
non-O157
Year Numbers of VTEC cases
Incidence/100000
2002 68 1.7 2003 82 2.1 2004 51 1.4 2005 123 3.0 2006 159 3.7 2007 115 3.9 2008 223 5.3 2009 240 5.7 2010 202 4.8 2011 270 5.9
HSE-PHL-Dublin
VTEC incidence
0
1
2
3
4
5
6
7
Year 2002 Year 2003 Year 2004 Year 2005 Year 2006 Year 2007 Year 2008 Year 2009 Year 2010 Year 2011
Incidence/100000
Total
O157
non-O157
Year Numbers of VTEC cases
Incidence/100000
2002 68 1.7 2003 82 2.1 2004 51 1.4 2005 123 3.0 2006 159 3.7 2007 115 3.9 2008 223 5.3 2009 240 5.7 2010 202 4.8 2011 270 5.9
Year No. Samples Analysed*
% positive cases
2004 599 8.5 2005 996 12.3 2006 1360 11.7 2007 1468 10.8 2008 2403 9.3 2009 3550 6.8 2010 3283 6.2 2011 4943 5.5
HSE-PHL-Dublin
VTEC Serogroups
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
year 2004 year 2005 year 2006 year 2007 year 2008 year 2009 Year 2010 Year 2011
Other
O26
O157
HSE-PHL-Dublin
2011 VTEC serogroups
Serogroup vtx1(%) vtx2(%) vtx1+vtx2(%) Total No.(%) O157 0(0) 153(72.5) 58(27.5) 211 (100) O26 29(58) 1(2) 20(40) 50 (100) O111 0 0 1(100) 1 (100) O128ad 0 0 1(100) 1 (100) O145 0 3(100) 0 3 (100) O146 0 0 3(100) 3 (100) O150 0 0 2(100) 2 (100) O185 0 1(100) 0 1 (100) O5 6(75) 0 2(25) 8 (100) O76 1(100) 0 0 1 (100) O44 0 1(100) 0 1 (100) O91 0 0 1(100) 1 (100) O130 0 1(100) 0 1 (100) O149 1(100) 0 0 1 (100) O166 0 0 1(100) 1 (100) O6 4(100) 0 0 4 (100) O8 0 1 0 1 (100) Ungroupable 3(25) 4(33.4) 5(41.6) 12 (100)
2002-2011 33 serogroups +
2011: 17 serogroups 15 clinical +2 food
HSE-PHL-Dublin
2011 HPSC VTEC subgroup HPSC Ref lab 5 labs Public health
Consensus + recommend standardised methods for VTEC
HSE-PHL-Dublin
Risk
Risk USA ROI Scotland E&W Nordic
Bloody diarrhoea
HUS
Isolates
OB contacts symptomatic
Community acq Diarrhoea (O157) ? (O157) (O157) (optimal)
Food handler
Abdominal Cramps
Contact with ruminants
Consumption raw animal products or raw fruits/veg
Contact with animal products e.g. manure
Hospitalised
HSE-PHL-Dublin
“all stools submitted for routine testing from patients be simultaneously cultured for O157 and tested with an assay that detects Shiga toxins to detect non-O157 STEC”
“Specimens or enrichment broths in which Shiga toxin or STEC are detected but from which O157 STEC are not recovered should be forwarded as soon as possible to a state or local public health laboratory”.
Lab Methods US
HSE-PHL-Dublin
Lab Methods ROI
Method Risk 1 2 3 4 5 6
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High (outbreakO157)
Low
IMS High (outbreakO157) (O157, O26, O111)
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High
Low
HSE-PHL-Dublin
Lab 1Method Risk 1
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High
Low
IMS High
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High
Low
HSE-PHL-Dublin
Lab 1Method Risk 1
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High
Low
IMS High
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High Low
2012
HSE-PHL-Dublin
2012 2011 2010 2009
Jan-Apr 14(3xO103, 1xO111, 5x ungp, 1x O145, 4xO26)
0 0 1 (1x O105 ac)
Whole year
4(1x ungp, 1x O150, 1x O91, 1x O26) All picked up by ref lab as part of O157 OB screen
4(1xO121, 3x O26)
12(1x O105 ac, 4x ungp, 1x O145, 1x O103, 1x O178, 4x O26) 7 picked up by ref lab as part of OB screen
Pre 2012 samples referred to ref lab based on risk and not lab findings (stools).
HSE-PHL-Dublin
Lab 7 Method Risk 7
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High
Low
IMS High
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High
Low
HSE-PHL-Dublin
Lab 7 Method Risk 7
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High
Low
IMS High
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High
Low
STEC CHROMagar
HSE-PHL-Dublin
2012 2011 2010 2009
Jan-Apr 10(2x O145, 7x O26, 1x ungp)
1(1xO26)
0 2(2xO26)
Whole year
4(3x O26, 1x O5) O5 picked up by ref lab as part of OB screen
3(1xungp, 2xO26)
3(3xO26)
Pre 2012 samples referred to ref lab primarily based on lab findings and not risk (Isolates)
HSE-PHL-Dublin
Method Risk 2
CT-SMAC/Chrom
High
Low
Agglutination O157
High
Low
Enrichment High
Low
IMS High
Low
Non-O157 agglutination
High
Low
O157 gene detection
High
Low
VT gene detection
High
Low
Lab 2
No changes to methods
HSE-PHL-Dublin
2012 2011 2010 2009
Jan-Apr 14(14x O26)
12(9xO26, 3xO146)
2(2xO26)
4(4xO26)
Whole year
41(28x O26, 1x O150, 1xO44, 2xO5, 1xO76, 3xO146, 5x ungp)
27(27xO26)
12(5xO26, 3xungp, 2x O121, 2x O132)
samples referred to ref lab based on both lab findings and risk (stools and isolates)
HSE-PHL-Dublin
Issues
PCR Direct from stool PCR pos culture negative issue Direct detection of vt1 or vt2 gene(s) (without
strain isolation), probable or confirmed depending on clinical criteria (HPSC)
HSE-PHL-Dublin
Ref lab Direct PCR, Enrichment/IMS PCR, colony
confirmation.1. Direct PCR pos and/or Enrichment/IMS PCR
pos + colony confirmed
2. Direct PCR pos + Enrichment/IMS PCR pos but can’t isolate colony
3. Direct PCR pos + Enrichment/IMS PCR neg
Do 2 +3 have the same PH implications?
Issues
HSE-PHL-Dublin
2) Direct PCR pos + Enrichment/IMS PCR pos but can’t isolate colony
Organism seems to be growing viable Shedding of viable organism possible PH
risk Source of infection
HSE-PHL-Dublin
3) Direct PCR pos + Enrichment/IMS PCR neg Organism not growing not viable Shedding of non viable organism not a PH
risk May have been infection with organism
subsequently dying source of infection May have been no infection but ingestion of
non viable organism e.g. from treated water or processed food
HSE-PHL-Dublin
If Use PCR only result (2 or 3) may not be true result O26 vt2 PCR pos
O26 vt2 O26 vt neg + other serogroup vt2 pos O26 vt2 + other serogroup vt2 pos
HSE-PHL-Dublin
Challenges
Methods Risk Transport Facilities IT
HSE-PHL-Dublin
Summary
VTEC in recent years Particularly in non-O157 VTEC Introduction of mandatory notification Increased awareness non-O157 VTEC Recent increases of non-O157 VTEC can be
attributed to more targeted methods Challenges Clinical and lab findings need to be taken
together Lab + PH need to communicate
HSE-PHL-Dublin
Thank You
Thank you to dedicated PHL Staff
HSE-PHL-Dublin
Outbreak Service Primary High Risk sample analysis Confirmation and Typing Medical advisory service OCT Data collation
VTEC Reference Service