HEV in Belgium: An import infection or an emerging viral zoonosis?

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HEV in BelgiumAn import infection or an
emerging viral zoonosis?

• I.Micalessi, I.Thomas, B. Brochier
• National Center of Viral Hepatitis

Rue Juliette Wytsmanstraat 14 1050 Brussels
Belgium T 32 2 642 50 73 F 32 2 642 56 92
email Isabel.Micalessi_at_iph.fgov.be
www.iph.fgov.be
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Characteristics of HEV (1)

• Symptoms
• similar to hepatitis A virus
• Transmission
• mainly faecal-oral route ? faecal contamination
  of drinking water
• transmission by blood transfusion may be possible
• Clinical Evolution
• Acute self-limited or fulminant hepatitis
• Chronic hepatitis reported in organ transplant
  recipients
• Low mortality 1-3
• Exception pregnant women 15-25
• HEV IgG prevalence
• Blood donors 1-3
• Persons working with swine prevalence much higher

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Characteristics of HEV (2)

• ssRNA virus (7.2kb), non-enveloped
• only member of the genus Hepevirus
• in family Hepeviridae
• 5 genotypes

HEV genotype Geographic distribution
1 (human) Asia, Africa
2 (human) Mexico
3 (human swine) Europe, United States
4 (human swine) China, Taiwan, Japan
5 (avian) Australia, United States
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HEV a new public health concern?
Risk of transmission
Endemic regions developing countries contaminated drinking water Non-endemic regions industrialized countries import infection Zoonosis? suspicion of swine/wild boar as animal reservoir e.g. The Netherlands HEV suspected transmission from swine to human without travel history is increasing (gt 3 with 91-97 homology between human and Dutch pig strains) e.g. Japan HEV transmission associated with eating of raw or undercooked wild boar and deer meat


5
(weeks)
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Laboratory diagnosis

• HEV IgG and IgM
• screening HEV IgM and IgG ELISA (MP
  diagnostics)
• confirmation HEV IgG/IgM recomBlot
  (since 2008) (Mikrogen)
• HEV RNA
• nested PCR (primers in ORF 2 region,
  Gyarmati et al, 2007)

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HEV in Belgium preliminary results (1)
year total IgM IgM IgG IgG HEV RNA
year total ELISA BLOT ELISA BLOT PCR
2006 46 36 / 28 / 12
2007 45 38 / 24 / 9
2008 24 21 7 6 4 3
2009 6 4 2 3 2 2
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HEV in Belgium preliminary results (2)
HEV gt 3 is present in Belgium High homology to
swine isolate from the Netherlands ? zoonotic
transmission of HEV possible
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Conclusions

• Sequencing in progress to determine the
  prevalence of the HEV genotypes circulating in
  Belgium.
• High homology between human and swine gt3
  suggesting a viral zoonosis in Belgium
• ? Risk factors prevention measures
• Standardised reference material (HEV RNA) and
  inter-laboratorium panel testing necessary

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Acknowledgments

• RIVM, the Netherlands
• J. Reimerink
• IPH, Group of Virology
• I. Fdillate
• I. Thomas
• C. Gérard