di , 14/02/2024

A nationwide, agnostic retrospective cohort study has made use of routine health-care data to proactively search for unknown transfusion-transmitted diseases.

The study, published in the Lancet Digital Health, highlights the importance of identifying and preventing transfusion-transmitted diseases to ensure the safety of blood transfusions. By leveraging a combination of health-data registers and blood-bank databases, researchers aimed to uncover potential threats to the blood supply that may not have been previously identified.

Methodology and Findings

The study, conducted in Sweden, developed a systematic algorithm for a population-wide search for transfusion-transmitted diseases. This approach did not consider any preconceived notions about blood-borne transmissibility. The researchers analyzed a nationwide transfusion database called SCANDAT-3S, encompassing data on 1.72 million patients who had undergone 18.97 million transfusions between 1968 and 2017. They also examined the health outcomes of both blood donors and transfusion recipients through various national registers.

The study identified evidence of transfusion-transmission for 15 diseases, 13 of which were validated using a second approach. Among the diseases confirmed to be transfusion-transmitted were viral hepatitis and its complications, as well as other conditions such as pneumonia of unknown origin. However, the study did not find statistically significant evidence for transmission of HIV or abnormal findings in specimens from male genital organs after adjusting for multiple testing. The effect sizes for other conditions were found to be small.

Implications and Significance

The findings of this research provide valuable insights into the presence or absence of unknown transfusion-transmitted diseases within the Swedish blood donor pool. The study suggests that there is no strong evidence to support the existence of widespread transmission of unknown transmissible agents. Moreover, the study serves as a proof-of-concept for utilizing data-driven surveillance, using routinely collected health-care and blood-bank data, to proactively detect transfusion-transmitted diseases.

The implementation of various preventive measures, including donor selection and improved screening tests, has significantly reduced the risks associated with known transfusion-transmitted pathogens. However, the study highlights the ongoing need for systematic efforts to detect and assess the risks and consequences of unknown transfusion-transmitted diseases.

This research adds to the existing evidence on transfusion-transmitted infections, demonstrating the importance of ongoing surveillance and the incorporation of routine health-care data in identifying and addressing potential risks. The results of this study contribute to the enhancement of transfusion safety protocols and further the understanding of transfusion-transmitted diseases.

Funding and Future Research

The study received funding from multiple sources, including the Department of Health and Human Services, the US National Heart, Lung, and Blood Institute, the US National Institutes of Health, the Swedish Research Council, and Region Stockholm. Moving forward, continued research in agnostic surveillance for transfusion-transmitted diseases using routine health data will be crucial in refining preventive strategies and ensuring safe blood transfusions.


The nationwide study conducted in Sweden demonstrates the power of utilizing routine health-care data to search for unknown transfusion-transmitted diseases. By proactively identifying and addressing potential risks, this research contributes to the ongoing efforts to ensure the safety and efficacy of blood transfusions. The findings serve as a foundation for future research and public health interventions aimed at minimizing the risks associated with transfusion-transmitted diseases.