HEV + some hep A Flashcards
HEV family and Baltimore group
Hepeviridae
Group 4 (ss +ve RNA) Non enveloped, may have a quasi-envelope in blood from exit of cells, but not in stool.
HEV Species, Genotypes and associated species
Species A, B, C and D only A and C causes infections in humans.
Genotypes A:
1 and 2 humans (Asia and Africa)
3 and 4 (pigs - zoonotic infections in humans)
5 and 6 (wild bore)
7 and 8 ( camels, 1 human case of G7 in an individual who regularly consumed camel meat and milk)
C1 - rat hepatitis E, human cases seen responds to Ribavirin
HEV historic outbreaks genotype 1 and 2
India
1950 Delhi
1978-9 Kashmir - high mortality in pregnancy
More recently,
there have been ongoing, stuttering outbreaks in African refugee
camps, including recent and ongoing outbreaks in South Sudan,
Niger, Nigeria and Namibia.
HEV genotype 1 and 2
Attack rate
Chronic infection
Mortality in pregnancy
1 in 5
No
25%
Where are the hot spots for HEV in Europe?
Southwest France (incidence 3–4%)
The Netherlands (1:600 blood donors
viraemic, 2014)
Scotland (1:2,481 donors viraemic, 2016)
western Germany (1:616 blood donors viraemic, 2015)
Czech Republic (400 laboratory-confirmed cases 2015)
Abruzzo, central Italy (seroprevalence 49%)
western/central Poland
(seroprevalence 50%)
What is HEVnet?
Created by the Dutch National Institute for Public Health
and the Environment (RIVM) in the Netherlands. The objective
of this exercise is to develop a central repository for human and
animal HEV sequences, together with key anonymised clinical
data from human cases. ‘HEVnet’ is, therefore, likely to be a very
important tool for improving the future understanding of HEV
epidemiology.
Patients with confirmed HEV should be monitored for normalisation of what markers (4)
ALT
AST
INR
BILIRUBIN
What is the attack rate for Genotype 3 and 4 HEV
5%
Is HEV immunity sterilising
No, but repeat infections are likely to be milder / subclinical
What are the extra hepatic manifestations of HEV?
1) neurological: neuralgic amyotrophy (NA), Guillain-Barré syndrome
(GBS), encephalitis/myelitis, mononeuritis multiplex, Bell’s palsy, vestibular neuritis, myositis and peripheral neuropathy.
The best documented are NA, GBS, and encephalitis/myelitis
2) Renal: Membranoproliferative and
membranous glomerulonephritis, IgA nephropathy.
3) Haematological: Thrombocytopenia, Monoclonal immunoglobulin, Cryoglobulinemia, Aplastic anaemia, Haemolytic anaemia.
4) Other: Acute pancreatitis, Arthritis, Myocarditis, Autoimmune thyroiditis.
HEV treatment in chronic infection
1) reduce immunosuppression (lower TAC = 1/3 clearance)
2) 3/12 Ribavirin
3) 6 /12 Ribavirin
4) Pegylated interferon-a for 3 months in liver-transplant patients. No alternative available therapy in other transplant patients.
Who should be considered for HEV Rx? (3)
1) Severe acute HEV
2) Acute on chronic hepatitis with HEV
3) Chronic HEV in immunocompromised
4) Insufficient data to recommend Ribavirin in pregnancy as teratogenic.
How does Ribavirin inhibit HEV?
It has been suggested that ribavirin inhibits HEV replication by depleting guanosine triphosphate (GTP) pools
Emerging HEV therapeutic?
Sofosbovir in vitro (NS5B RDRP inhibitor), No in Vivo data. May have additive effect with Ribavirin
HEV vaccine. Where is it used? efficacy? Based on? Cross protection?
Licenced in China in 2011
Vaccine efficacy 97% preventing symptomatic episodes - not sterilising immunity.
Contains amino acid from HEV genotype 1 ORF2 protein relating to viral capsid.
Cross protection likely and observed against genotype 4
