title: Hepatitis E virus in blood components: a prevalence and transmission study in southeast England.
abstract: BACKGROUND
  The prevalence of hepatitis E virus (HEV) genotype 3 infections in the English population (including blood donors) is unknown, but is probably widespread, and the virus has been detected in pooled plasma products. HEV-infected donors have been retrospectively identified through investigation of reported cases of possible transfusion-transmitted hepatitis E. The frequency of HEV transmission by transfusion and its outcome remains unknown. We report the prevalence of HEV RNA in blood donations, the transmission of the virus through a range of blood components, and describe the resulting morbidity in the recipients.
  
  
  METHODS
  From Oct 8, 2012, to Sept 30, 2013, 225,000 blood donations that were collected in southeast England were screened retrospectively for HEV RNA. Donations containing HEV were characterised by use of serology and genomic phylogeny. Recipients, who received any blood components from these donations, were identified and the outcome of exposure was ascertained.
  
  
  RESULTS
  79 donors were viraemic with genotype 3 HEV, giving an RNA prevalence of one in 2848. Most viraemic donors were seronegative at the time of donation. The 79 donations had been used to prepare 129 blood components, 62 of which had been transfused before identification of the infected donation. Follow-up of 43 recipients showed 18 (42%) had evidence of infection. Absence of detectable antibody and high viral load in the donation rendered infection more likely. Recipient immunosuppression delayed or prevented seroconversion and extended the duration of viraemia. Three recipients cleared longstanding infection after intervention with ribavirin or alteration in immunosuppressive therapy. Ten recipients developed prolonged or persistent infection. Transaminitis was common, but short-term morbidity was rare; only one recipient developed apparent but clinically mild post-transfusion hepatitis.
  
  
  CONCLUSIONS
  Our findings suggest that HEV genotype 3 infections are widespread in the English population and in blood donors. Transfusion-transmitted infections rarely caused acute morbidity, but in some immunosuppressed patients became persistent. Although at present blood donations are not screened, an agreed policy is needed for the identification of patients with persistent HEV infection, irrespective of origin, so that they can be offered antiviral therapy.
  
  
  BACKGROUND
  Public Health England and National Health Service Blood and Transplant.
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK.
authors: Patricia E
authors: PE
authors: Hewitt
authors: Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Samreen
authors: S
authors: Ijaz
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
authors: Su R
authors: SR
authors: Brailsford
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK.
authors: Rachel
authors: R
authors: Brett
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Steven
authors: S
authors: Dicks
authors: Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Becky
authors: B
authors: Haywood
authors: Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
authors: Iain T R
authors: IT
authors: Kennedy
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK.
authors: Alan
authors: A
authors: Kitchen
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Poorvi
authors: P
authors: Patel
authors: Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: John
authors: J
authors: Poh
authors: Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
authors: Katherine
authors: K
authors: Russell
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Kate I
authors: KI
authors: Tettmar
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK.
authors: Joanne
authors: J
authors: Tossell
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK.
authors: Ines
authors: I
authors: Ushiro-Lumb
authors: Transfusion Microbiology, National Health Service Blood and Transplant, London, UK; Blood Borne Virus Unit, Virus Reference Department, Microbiology Services, Public Health England, London, UK; University College London, Gower Street, London, UK. Electronic address: richard.tedder@phe.gov.uk.
authors: Richard S
authors: RS
authors: Tedder
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D016913:Blood Component Transfusion / Q000009:adverse effects* / Q000379:methods; D015331:Cohort Studies; D003140:Communicable Disease Control / Q000379:methods*; D018562:Disease Transmission, Infectious / Q000706:statistics & numerical data*; D004739:England / Q000453:epidemiology; D005260:Female; D005838:Genotype; D016751:Hepatitis E / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control / Q000635:transmission*; D016752:Hepatitis E virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D065227:Transfusion Reaction