Hepatitis E virus (HEV) infection is an emerging infectious disease. HEV-1 and HEV-2 infect humans through contaminated water and foods, mainly in developing countries. HEV-3 and HEV-4 also infect humans through contaminated food and are thought to be zoonotic infections occurring in both developing and developed countries. A vaccine for hepatitis E is licensed in only limited countries. The inactivation of infectious HEV is very important to ensure the safety of drinking water and foods. HEV-3 and HEV-4 RNA have been detected in some pig liver products, and it is possible that these foods may represent an infectious source of HEV. In this article, previous publications on the heat inactivation and heat stability of HEV are collected, and we discuss the present assessment of the heat inactivation of HEV. The thermal stability of HEV infection in cell culture systems and pig bioassays has been demonstrated, while the efficacy of the method of thermal inactivation using plasma products has not yet been established. Here, we propose that the treatment of HEV-contaminated foods at 95 °C for 10 min is one of the safest options for the inactivation of HEV.

Clinical application of pathogen-reduction technology (PRT) is often restricted to platelet and non-cellular components, representing a minor fraction of the overall blood supply. The greatest benefit for patient safety may eventually derive from PRT in red cells, which is still unavailable for routine use. PRT is more effective to inactivate leukocytes than current irradiation, particularly pertinent for Japan with the only universal irradiation of cellular blood components. Elsewhere, only vulnerable patient cohorts are receiving irradiated cellular components. Blood components treated with approved PRT systems are exempt from irradiation if the patient requires irradiated components. Transfusion medicine has a strategic opportunity to develop and eventually utilize PRT for all cellular components, other than hematopoietic progenitor cell products. PRT would then enable leukocyte inactivation for 100 % of the blood supply, beneficial for transfusion safety in all patients.

The recent COVID-19 pandemic has significantly challenged blood transfusion services (BTS) for providing blood products and for keeping blood supplies available. The possibility that a similar pandemic event may occur again has induced researchers and transfusionists to investigate the adoption of new tools to prevent and reduce these risks. Similarly, increased donor travelling and globalization, with consequent donor deferral and donor pool reduction, have contributed to raising awareness on this topic. Although recent studies have validated the use of pathogen reduction technology (PRT) for the control of transfusion-transmitted infections (TTI) this method is not a standard of care despite increasing adoption. We present a critical commentary on the role of PRT for platelets and on associated problems for blood transfusion services (BTS). The balance of the cost effectiveness of adopting PRT is also discussed.

Acute hepatitis E was considered rare until reports emerged affirming the existence of hepatitis E virus (HEV) genotypes 3 and 4 infections in Japan in the early 2000s. Extensive studies by Japanese researchers have highlighted the pivotal role of pigs and wild animals, such as wild boars and deer, as reservoirs for HEV, linking them to zoonotic infections in Japan. Currently, when hepatitis occurs subsequent to the consumption of undercooked or grilled pork, wild boar meat, or offal (including pig liver and intestines), HEV infection should be considered. Following the approval of anti-HEV immunoglobulin A antibody as a diagnostic tool for hepatitis E by Japan's Health Insurance System in 2011, the annual number of diagnosed cases of HEV infection has surged. Notably, the occurrence of post-transfusion hepatitis E promoted nationwide screening of blood products for HEV using nucleic acid amplification tests since 2020. Furthermore, chronic hepatitis E has been observed in immunosuppressed individuals. Considering the significance of hepatitis E, heightened preventive measures are essential. The Japan Agency for Medical Research and Development Hepatitis A and E viruses (HAV and HEV) Study Group, which includes special virologists and hepatologists, held a virtual meeting on February 17, 2024. Discussions encompassed pathogenesis, transmission routes, diagnosis, complications, severity factors, and ongoing and prospective vaccination or treatments for hepatitis E. Rigorous assessment of referenced studies culminated in the formulation of recommendations, which are detailed within this review. This comprehensive review presents recent advancements in HEV research and Japanese clinical practice guidelines for HEV infection.

Cellular cryo-electron tomography (cryo-ET) offers 3D snapshots at molecular resolution capturing pivotal steps during viral infection. However, tomogram quality depends on the vitrification level of the sample and its thickness. In addition, mandatory inactivation protocols to assure biosafety when handling highly pathogenic viruses during cryo-ET can compromise sample preservation. Here, we focus on different strategies applied in cryo-ET and discuss their advantages and limitations with reference to severe acute respiratory syndrome coronavirus 2 studies. We highlight the importance of virus-like particle (VLP) and replicon systems to study virus assembly and replication in a cellular context without inactivation protocols. We discuss the application of chemical fixation and different irradiation methods in cryo-ET sample preparation and acquisition workflows.

Hepatitis E virus (HEV) is a major cause of viral hepatitis globally. There is growing concern about transfusion-transmitted HEV (TT-HEV) as an emerging global health problem. HEV can potentially result in chronic infection in immunocompromised patients, leading to a higher risk of liver cirrhosis and even death. Between 0.0013% and 0.281% of asymptomatic blood donors around the world have HEV viremia, and 0.27% to 60.5% have anti-HEV immunoglobulin G. HEV is infectious even at very low blood concentrations of the virus. Immunosuppressed patients who develop persistent hepatitis E infection should have their immunosuppressant regimen reduced; ribavirin may be considered as treatment. Pegylated interferon can be considered in those who are refractory or intolerant to ribavirin. Sofosbuvir, a nucleotide analog, showed modest antiviral activity in some clinical studies but sustained viral response was not achieved. Therefore, rescue treatment remains an unmet need. The need for HEV screening of all blood donations remains controversial. Universal screening has been adopted in some countries after consideration of risk and resource availability. Various pathogen reduction methods have also been proposed to reduce the risk of TT-HEV. Future studies are needed to define the incidence of transmission through transfusion, their clinical features, outcomes and prognosis.