Hepatitis E virus blood donor NAT screening: as much as possible or as much as needed?

Transfusion. 2019 Feb;59(2):612-622. doi: 10.1111/trf.15058. Epub 2018 Dec 13.

Abstract

Background: The cost-benefit question of general screening of blood products for the hepatitis E virus (HEV) is currently being discussed. One central question is the need for individual nucleic acid amplification techniques (NAT) screening (ID-NAT) versus minipool NAT screening (MP-NAT) approaches to identify all relevant viremias in blood donors. Here, the findings of ID-NAT versus MP-NAT in pools of 96 samples were compared.

Study design and methods: From November 2017 to January 2018, a total of 10,141 allogenic blood donations from 7650 individual German blood donors were screened for the presence of HEV RNA using MP-NAT (96 samples) (RealStar HEV RT-PCR Kit) compared to ID-NAT (cobas HEV assay) on the fully automated cobas 6800 platform.

Results: Parallel screening of MP (n = 122, 96 samples/MP) using both methods detected seven reactive pools. After pool resolution, 8 HEV RNA-positive donations were identified by the in-house detection method, whereas 17 HEV RNA-positive donations were identified by ID-NAT with the cobas HEV assay. This resulted in an incidence of 1:1268 donations (0.079%) for MP-NAT screening and 1:597 donations (0.168%) for ID-NAT screening.

Conclusions: The detection frequency of HEV RNA was approximately 50% higher if ID-NAT was used compared to MP-NAT. However, viral loads of ID-NAT-only samples were below 25 IU/mL and will often not result in transfusion-transmitted HEV (TT-HEV) infection, taking into account the currently known infectious dose of 5.0E + 04 IU inevitably resulting in TT-HEV infection. The clinical relevance and need for identification of these low-level HEV-positive donors still require further investigation.

MeSH terms

  • Adult
  • Blood Donors*
  • Donor Selection
  • Female
  • Hepatitis E / blood*
  • Hepatitis E / genetics
  • Hepatitis E virus*
  • Humans
  • Male
  • Middle Aged
  • Nucleic Acid Amplification Techniques*
  • Viral Load
  • Viremia / blood
  • Viremia / genetics