Introduction: Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latterMaterials and Methods: A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard. Results: For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs. Conclusion: DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.
Dried blood spot (DBS) or dried plasma spot (DPS) collection offers to be a promising alternative to whole blood or plasma sampling, as it has technical and economic advantages when compared to the latter. In the HIV-1 setting, the feasibility of using DBS technology for human immunodeficiency virus (HIV) surveillance was first tested in several studies in Europe, United States and the rest of the world in the late 1980s. Furthermore, studies conducted on DBS/DPS samples in resource-limited settings have proven the usefulness and accuracy of these samples for the serological and molecular diagnosis of HIV infection. These studies prove that DBS/DPS sampling is effective for the detection of HIV-1 p24 antigen5 and of HIV-1 DNA, for serotyping, for quantification of HIV-1 RNA, for genotyping and for the monitoring of drug resistance.
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