Hepatitis E Virus (HEV)

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Record number: 
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
Variable frequency, but likely to be high, depending on inocum size and local seroprevalence. A UK study by Hewitt et al revealed a 42% transmission rate across different blood component types.
Time to detection: 
Within 27 days after red blood cell (RBC) transfusion, acute flaccid paralysis developed.
Alerting signals, symptoms, evidence of occurrence: 
A 56 year old man received heart transplantation for Emery Dreifuss laminopathy, due to severe heart failure. Within 27 days from exposure to RBC via ECMO from an asymptomatic HEV-infected blood donor and within 15 days after heart transplantation from an organ donor who was not infected by HEV, the patient developed respiratory and limb weakness. This progressed to quadriparalysis, multi organ failure and death 153 days after transplant. At postoperative day 70, mild elevation of liver function tests prompted testing and he was found to be HEV IgM, IgG and RNA positive. HEV RNA was amplified from CSF; he was commenced on low dose Ribavirin due to haematological intolerance and virological suppression could not be achieved. He was diagnosed with a HEV-related acute inflammatory polyradiculopathy. The patient’s serum sample from postop day 56 was positive for HEV RNA. No samples were available from the patient following transfusion and transplantation prior to development of respiratory and limb paresis. Therefore the length of the seronegative incubation period could not be determined.
Demonstration of imputability or root cause: 
Definite. All 43 blood donors of transfusions given before transplant were tested, and one donor was positive for HEV RNA and negative for anti-HEV. The patient tested negative for anti-HEV and HEV RNA at the time of transplant. Phylogenetic analysis of Orf2 nucleic acid sequences of the 2 strains showed 100% homology, and differences to other unrelated strains.
Imputability grade: 
3 Definite/Certain/Proven
Suggest new keywords: 
hepatitis, acute demyelinating neuropathy, acute inflammatory polyradiculoneuropathy, acute paralysis, heart transplant,
Reference attachment: 
Suggest references: 
Belliere J et al. Transfusion-acquired hepatitis E infection misdiagnosed as severe critical illness polyneuromyopathy in a heart transplant patient. Transpl Infect Dis. 2017;19:e12784
Expert comments for publication: 
The commonest route of HEV genotype 3 acquisition is via consumption of food containing undercooked pork meat. Asymptomatic viraemia is very common and transfusion-transmitted HEV is commonly described; in the immunocompromised, particularly in recipients of solid organ transplants, there is a risk of persistent infection and accelarated liver disease. HEV-related extra hepatic symptoms have been described, including neurological manisfestations. The natural history of disease in HEV genotype 3 infection is very different from that described for HEV genotype 1, which is known to cause severe hepatitis in pregnant women but has not been associated with increased morbidity in the immunocompromised host.