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Background and Objectives: South Africa has a high prevalence of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) and to a lesser extent human T-lymphotropic virus (HTLV). Each of these agents is transfusion-transmissible (TT) but deciding whether to implement preventive screening depends upon knowledge of background prevalence in transfused patients. We determined the prevalence of HIV, HBV and HTLV I/II among blood transfusion recipients in South African hospitals., Materials and Methods: We obtained identity-unlinked samples used for blood cross-matching at 634 South African hospitals served by the South African National Blood Service (SANBS). The ABBOTT Alinity S® Immunochemiluminescent system measured HIV, HBV and HTLV I/II antibodies. Repeatedly reactive samples were confirmed using the Roche Cobas® 8000. Logistic regression was performed to investigate the determinants of associations for HIV, HBV and HTLV infections., Results: The overall prevalences of HIV, HBV and HTLV were 37.8%, 7.4% and 0.6%, respectively. The HIV prevalence in blood recipients was twice as high as general population estimates. Public hospital patients had a significantly higher prevalence compared with private hospital patients for HIV and HBV. HIV prevalence was significantly higher in females, and HBV prevalence was significantly higher in males, excluding the unknown gender results., Conclusion: Patients receiving blood transfusions in South Africa have high rates of HIV and HBV infection that should be taken into consideration when determining donor screening strategies for other viral infections. Measurable prevalence of HTLV indicates endemicity of this infection in South Africa., (© 2024 The Author(s). Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)

Background: The clinical utility of radiomics is hampered by a high correlation between the large number of features analysed which may result in the "bouncing beta" phenomenon which could in part explain why in a similar patient population texture features identified and/or cut-off values of prognostic significance differ from one study to another. Principal component analysis (PCA) is a technique for reducing the dimensionality of large datasets containing highly correlated variables, such as texture feature datasets derived from FDG PET images, increasing data interpretability whilst at the same time minimizing information loss by creating new uncorrelated variables that successively maximize variance. Here, we report on PCA of a texture feature dataset derived from 123 malignant melanoma lesions with a significant range in lesion size using the freely available LIFEx software., Results: Thirty-eight features were derived from all lesions. All features were standardized. The statistical assumptions for carrying out PCA analysis were met. Seven principal components with an eigenvalue > 1 were identified. Based on the "elbow sign" of the Scree plot, only the first five were retained. The contribution to the total variance of these components derived using Varimax rotation was, respectively, 30.6%, 23.6%, 16.1%, 7.4% and 4.1%. The components provided summarized information on the locoregional FDG distribution with an emphasis on high FDG uptake regions, contrast in FDG uptake values (steepness), tumour volume, locoregional FDG distribution with an emphasis on low FDG uptake regions and on the rapidity of changes in SUV intensity between different regions., Conclusions: PCA allowed to reduce the dataset of 38 features to a set of 5 uncorrelated new variables explaining approximately 82% of the total variance contained within the dataset. These principal components may prove more useful for multiple regression analysis considering the relatively low numbers of patients usually included in clinical trials on FDG PET texture analysis. Studies assessing the superior differential diagnostic, predictive or prognostic value of principal components derived using PCA as opposed to the initial texture features in clinical relevant settings are warranted., (© 2022. The Author(s).)