57. Jahrestagung der Deutschen Gesellschaft für Transfusionsmedizin und Immunhämatologie

PD Dr. rer. nat.

Vorsitz

PD Dr. med.

Bakterielles Risiko von Thrombozytenkonzentraten – 14 Jahre Erfahrung mit bakteriellen Schnelltestverfahren

Prof. Dr. med.

Referent

Lecture

Empfehlungen für die In-vitro-Validierung von Blutprodukten in non-DEHP-Beuteln

Prof.

Parvovirus B19 nucleic acid detection rates in German blood donors before, during and after the restrictions of the SARS-Cov2 pandemic (2015-2024)

Blood Safety and Transfusion Transmitted Infections

Parvovirus B19-Nukleinsäure-Nachweisraten bei deutschen Blutspendern vor, während und nach den Einschränkungen der SARS-Cov2-Pandemie (2015-2024)

In healthy adults, parvovirus B19 (PVB19) usually causes mild symptoms like fever and itching when infecting red blood cells. But in immunosuppressed or those with high red blood cell turnover, severe complications like chronic pure red cell aplasia or transient aplastic crisis can arise. Besides respiratory transmission, infection through blood products is possible, leading to virus testing of blood products in Germany.Between January 2015 and April 2024, we screened 2,105,755 blood donations for PVB19. DNA was extracted from pools of 96 samples and specific detection of nucleic acid was carried out using a polymerase chain reaction. Incidences were determined for three different periods: January 2015 - March 2020 (pre-COVID-19), April 2020 - March 2023 (during COVID-19 pandemic; end of the mask requirement in the public sector in Germany in April 2023) and April 2023 - March 2024 (post-COVID-19).In the periods defined above, a total of 242 PVB19 positive donations were identified. For the first period under consideration (2015 - 2020), 101 PVB19 positives were found in a total of 1,228,361 donations, resulting in an incidence of 0.83 per 10,000 donations. In the second period (2020 - 2023), PVB19 was detected in 4 of 621,222 donations, resulting in an incidence of 0.06 per 10,000 donations in this period. Within the third period (2023 - 2024), PVB19 was detected in 137 of 235,088 donations, resulting in an incidence of 5.35 per 10,000 donations with a striking increase in incidence between December 2023 and March 2024 (4.3 to 21.1/10,000 donations), challenging the testing regime of blood donation services.Most of the population is immune to PVB19, as immunity from a single infection usually lasts a lifetime. This is accompanied by a stable incidence, as we observed between 2015 and 2020. In our study, the interventions taken because of the SARS-Cov2 pandemic, such as mandatory masks and social distancing rules, also led to a drastic decline in the number of PVB19 infections as PVB19 is transmitted mainly via the respiratory route. A relapse to higher incidence than pre-COVID19 was recorded after the measures ended. In summary, the data from our routine blood donation testing provides interesting insights into the epidemiology of PVB19 and underline that the hygiene interventions during the COVID19 pandemic had a lasting impact on PVB19 infection rates.Funding statement: T.V. was supported by the German Federal Ministry of Education and Research (BMBF, project HepEDiaSeq — FKZ 01EK2106A).

Abstract lecture

Update on HEV infections in blood donors in Germany – half of all infections are missed by current testing

Update zu HEV-Infektionen bei Blutspendenden – nur die Hälfte der Infektionen wird mit der aktuellen Teststrategie erkannt

In order to avoid transfusion-transmitted HEV infections, universal testing was implemented in 2020 with a minimal detection limit of 2,000 IU/mL on individual donation level to ensure the identification of high viremic donations. No definite quantification of the infectious dose has been published. Some case reports suggest that 7,000-10,000 IU HEV can be sufficient to cause clinical disease. Here we report data on HEV infections from the donor epidemiology supplemented by an estimation of the number of HEV infections missed by testing.Data from the national blood donor surveillance included the number of HEV infections stratified for sex, age group and region. Limits of detection (LoD) were provided by the blood establishments (BE). Estimation of undetected HEV infections was made for each BE that provided an LoD using the distribution of viral loads in 1,200 blood donors published by Harvala et al. (https://doi.org/10.3201/eid2809.220487). Data on symptomatic HEV infections in the general population was used for comparative analysesAltogether, 11,514 HEV infections were reported from 2020 to 2023 (data included until April 2024).HEV/100,000 donors ranged from 208.6 in 2021 to 280.2 in 2023. 1 in 1,470 donations was HEV-RNA-positive. Most HEV infections were identified in the age group 35-54 years and prevalence was 1,5 times higher in male than in female donors. Regional differences were found with highest incidence in Brandenburg (271/100,000) and lowest in Baden-Wurttemberg (109/100,000) resembling the distribution of reported clinical cases. We received the LoD for BE that discovered 10,1501 of the 11,514 HEV infections (88.2%). Test sensitivities ranged from 36-1,785 IU/mL. Applying the published distribution of HEV viral loads for each BE individually, the expected total number of HEV infections would have been 19,761, 1.95 times higher than the actually discovered number of infections.From 2020 to 2023 1 in 1,470 donations had measurable HEV viremia. The calculated expected number of HEV-positive donations is nearly twice as high. Still, transfusion transmitted HEV infections steeply declined using data from passive hemovigilance but also from the donor derived lookbacks. While the currently mandated LoD for HEV testing seems justified to provide an acceptable level blood safety, the infection pressure in the general population has to be closely monitored to allow for possible adjustments.Both authors declare no conflicts of interest.

Raum 27

Sicherheit von Blutprodukten

Sektionssitzungen

Sicherheit von Blutprodukten

Termin

Vorsitz

Sprache

Programm