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

I.Micalessi, I.Thomas, B. Brochier

National Center of Viral Hepatitis

Rue Juliette Wytsmanstraat 14 | 1050 Brussels | BelgiumT +32 2 642 50 73| F +32 2 642 56 92 | email: Isabel.Micalessi@iph.fgov.be | www.iph.fgov.be

Characteristics of HEV (1)Symptoms:similar to hepatitis A virus

Transmission: mainly faecal-oral route → faecal contamination of drinking watertransmission by blood transfusion may be possible

Clinical Evolution Acute self-limited or fulminant hepatitis Chronic hepatitis reported in organ transplant recipientsLow mortality: 1-3%Exception pregnant women: 15-25%

HEV IgG prevalence Blood donors: 1-3%Persons working with swine: prevalence much higher

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

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 reservoire.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

(weeks)

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)

HEV in Belgium: preliminary results (1)

year total

IgM + IgG + HEV RNA +

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

HEV in Belgium: preliminary results (2)

HEV gt 3 is present in BelgiumHigh homology to swine isolate from the Netherlands zoonotic transmission of HEV possible

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

Acknowledgments

RIVM, the Netherlands

J. Reimerink

IPH, Group of Virology

I. Fdillate

I. Thomas

C. Gérard