Mustafa EM Yassin, Walid A Eldaif and Isam M Elkhider
Objective: To evaluate the uses of dry blood spot stored at 37°C, 45°C, and 50°C for detection for HIV antibodies by using Rapid test. Methods: 95 blood specimens were used in this study, 50 specimens were collected from HIV positive and 45 collected from HIV non reactive patient, Dry Blood Spots (DBS) were prepared by applying 50 μl of whole blood on Whatman 3 filter paper (Whatman International® Ltd.), specimens of all DBS were stored at 37°C, 45°C and 50°C. All DBS were tested with two rapid tests (ACON ® One Step Test Device) and (ACCURATE ® test device) and to evaluate the effect of storage temperature and time on sensitivity and specificity, DBS were tested after 2 weeks, 4 weeks and 8 weeks. Results: After 2 weeks 48 out of 50 HIV-positive DBS were positive, and all 45 HIV-negative DBS were negative, at the different temperatures with both ICT test devices, with sensitivity of (96%) and specificity of (100%). After 4 weeks at 37°C, no change was reported in sensitivity and specificity with the both rapid tests. There was decrease in sensitivity after 8 week storage, especially at higher temperatures 45°C and 50°C. Conclusion: When tested with rapid test, DBS stored at 37°C and 45°C showed good stability until 8 weeks, but when stored at 50°C it showed good stability until week 4 and it had less stability when stored for 8 weeks. The present study concluded that in area with high temperature such as Sudan DBS can be stored at room temperature and tested with rapid test within 4 weeks.
