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Hepatitis E Virus in England and Wales
Samreen Ijaz
Blood Borne Virus Unit
Virus Reference Dept
2
HEV in England and Wales
• New understanding of HEV infections in our population
• Established national programme of enhanced surveillance in 2003 (E&W)
• Viral hepatitis including Hepatitis E is a notifiable disease
• Developed case definitions and testing strategies (acute cases and for the
immunosuppressed)
• Recognise HEV as the most common cause of acute hepatitis in England and
Wales
3
• PHE case control study – (2012)
• 25 cases/75 matched controls
• food based questionnaire
• analysis suggests an association between the consumption of pork based
products and HEV infection
• Berto et al., 2012 provided evidence of HEV contamination in the
pork production chain
• 10% of sausages at point of sale HEV RNA positive
3
Investigating transmission routes in England
4 Presentation title - edit in Header and Footer4
Imported versus indigenous infection in England/Wales
0
100
200
300
400
500
600
700
800
900
1000
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Frequency
Year
Total
Indigenous
Travel1:7000
1:2850
Incidence in
blood donors
Molecular epidemiology
(2003-2013)
Presentation title - edit in Header and Footer
Group 2
2010-2013
Group 1
2003-2009
Nucleotide Subsitution per 100 residues
032.2 51015202530
6
Proportion of group 1 and 2 sequences - 2003-2014
0
50
100
150
200
250
300
350
400
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Freq
uen
cy
Year
Group 2
Group1
Change in the magnitude of risk
• Rise is case numbers associated with the emergence of a clade of
viruses not commonly circulating prior to 2010
• are these dominant viruses more transmissible?
• are these dominant viruses of different pathogenicity?
• How and WHERE have the risk factors changed?
• Changes in farming practices or animal husbandry?
• Changes in food processing or importation of meat?
7
2013 UK Pig Abattoir survey
• 93% seroprevalence rate in UK pigs
• ~6% viraemic at time of slaughter
• Pig viruses fall into group 1 of genotype 3
• 2/3rds of human infection in England fall into group 2 viruses of genotype 3
• Source of infection in or out of the UK?
• Cross European studies with a view to sequence data linkage and sharing
across human and pig sequences.
• Define the epizoology across Europe.
8
9
HEV and Blood Safety
• HEV RNA incidence found to be 1:2850 in donors
• Follow up investigations found 42% transmission rate from HEV-infected
blood components to recipients
• Plasma HEV viral load important factor for transmission
• Indication that products with lower plasma content less likely to be
associated with transmission
10
Public health implications of HEV have grown
• Remit goes beyond the recognition and characterisation of acute HEV
infections
• Recognition of chronic HEV infections in the immunosuppressed population
• PHE establishing a register to better understand and monitor these infections
• 60 cases of chronic hepatitis E
• Haem-oncology/HSCT patients
• SOT recipients
• HIV-infected individuals
11
HEV summary
• Now recognised as a widespread zoonosis associated with rolling infections in
England and Wales
• Currently in a period of heightened HEV activity; associated with the emergence
of a novel phylotype
• Europe wide collaborations to link HEV sequences from both human and pig
populations to inform options for control
• UK introducing HEV screening for donations given to SOT and SCT patients to
reduce exposure
• UK to consider how to identify and mitigate HEV risks in immunosuppression
12 Presentation title - edit in Header and Footer
AcknowledgementsPublic Health England NTMRL, NHSBT, Colindale
Richard Tedder Alan Kitchen
Dilys Morgan Ines Ushiro-Lumb
Bengu Said Pat Hewitt
David Brown Su Brailsford
Poorvi Patel
Becky Haywood Colleagues at APHA
Rachel Brett Colleagues at NHSBT
Steve Dicks Colleagues at BPEX
Kate Tettmar