Our annual business meeting was held as a hybrid in-person and online meeting at the European Congress on June 17, 2023 in Gothenberg, Sweden. The scientific session focused on updates on the public health tool kit resources developed by WP members, new findings and progress on pathogen reduction technologies, and the emerging issue of antiretroviral and pre-exposrue prophlylaxis use among blood donors. As part of the annual general meeting each subgroup provided updates on activities during the previous year. Each subgroup is very active in advancing research and policy related to TTID.

Bacteria

There are 30 TTID WP Individual Members whose primary affiliation is the Bacteria Subgroup. In progress activities include:

• Detection of bacterial endotoxins in platelet concentrates, five participant laboratories (study started in the summer of 2023 and included six specific meetings focused on this work).
• Bacterial growth in delayed cold-stored platelet components, six participant laboratories (study started in the fall of 2023).

Parasitology

There are 8 TTID WP Individual Members whose primary affiliation is the Parasites Subgroup. In progress activities include:

• Subgroup meeting June 2, 2023, which included a guest speaker presentation “Markers of current and past malaria infection in blood donors from the Philippines”, Iza Mae Chamen (Transfusion Transmissible Infections – National Reference Laboratory [TTI-NRL], Republic of the Philippines).
• Subgroup meeting October 24, 2023, which included a presentation by Dr. Luiz Luiz Amorim (General Director at Hemorio Blood Center, Rio de Janeiro, Brazil) on a novel plasma-based assay in use in Brazil for the detection of malaria in blood donors.
• Parasites subgroup chairs have been actively engaging speakers from outside of North America and Europe to deliver talks to subgroup members. A session focussing on nematodes is in the planning phase with the goal of focussing on parasitology topics with a non-European/North America focus. Subgroup leaders have also spent time brainstorming on how blood donor specimens could be used to support public health surveillance functions and fundable academic research projects.

Surveillance, Risk Assessment, and Policy (SRAP)

There are 25 TTID WP Individual Members whose primary affiliation is the SRAP Subgroup. In progress activities include meetings held to focus on assessments of policy regarding infectious risks, supporting services to implement change, and evaluating donor data to support public health, work includes:

• Several international surveys were undertaken, including a review of selection and testing for Chagas’ disease (with Parasitology Subgroup), the COVID-19 deferrals, current approaches to lookback, and NAT testing and yield (with Virology Subgroup).
• A review of public health activities regarding HBV alongside an evaluation of how donor data may contribute was initiated. SRAP supported mathematical modelling of impact of pathogen reduction technology and held a discussion with corporate colleagues around additional evidence needed to establish malaria NAT screening in non-endemic areas.
• A PrEP/PEP subgroup was established to help address issues in donors and model estimates of HIV breakthrough in donors. SRAP members continue to support implentation of a more individulaised approach to donor selction and in April 2023 many members contributed to an international symposium on alternatives to MSM deferrals.

Virology

There are 49 TTID WP Individual Members whose primary affiliation is the Virology Subgroup. In progress activities include:

• HBV infection vaccine breakthrough assessment: the project is halfway to completion with preliminary data presented at the 24th ANRS|EID AC42 Meeting, Paris, March 2024.
• Occult HBV infection (OBI) characterisation, prevalence, and follow-up; the studies are almost completed with two manuscripts in preparation and four communications in international congresses.
• An ongoing assessment of the need for anti-HCV donation testing when HCV ID-NAT is used.
• The 10-year NAT survey analysis and reporting have largely been completed with 2 published papers, and another 1-2 in various stages of review.

Completed manuscripts/publications

Publications directly stemming from TTID are listed below by Subgroup.

Bacteria

• Ramirez-Arcos S, Garcia M, and McDonald C. Microbiological environmental contamination in the blood supply chain: An international survey by the bacterial subgroup of the ISBT Transfusion-Transmitted Infectious Diseases Working Party.
• Special Issue “Safety of Platelet Concentrates: Past- Present and Future” in the journal “Microorganisms”, with Sandra Ramirez-Arcos as Guest Editor and Carl McDonald as Co-Guest Editor . Seven manuscripts published in December 2023 and January 2024.
• Two manuscripts summarizing work of the Bacterial Subgroup submitted to Vox Sanguinis in January 2024: