Background: Hepatitis B Virus is one of the major causes of global public health problems. Diagnosis of HBV is done by using ELISA and immune-chromatographic assays for detecting different serologic markers. Hepatitis B surface antigen (HBsAg) is the most frequently used serological marker employed to diagnosis HBV using Rapid Diagnostic Test (RDT) and Enzyme Linked Immunosorbent Assay (ELISA) methods. The RDT method is the most commonly used diagnostic tool in Ethiopia as well as in most African countries. Therefore assessing and knowing the diagnostic performance of the RDT is important.
Method: A prospective cross sectional study was done at University of Gondar comprehensive specialized Hospital from Feb, 2017- May, 2017. Ethical clearance was obtained from School of Biomedical and Laboratory Sciences Research Ethics Committee. Permission was obtained from Blood Bank office to use blood sample collected from voluntary blood donors. HBsAg was diagnosed using RDT and ELISA methods. ELISA considered as gold-standard to the performance of RDT. Data were entered into statistical package for social sciences (SPSS) version 20 software and analysis was done by using SPSS and for sensitivity, specificity, predictive value, and likelihood ratio Medi calc software. The agreement of the methods presented assessed using kappa value.
Result: Each 161 specimen was diagnosed using both ELISA (ADVANCED®) and RDT (Ecotest®). A total ELISA confirmed 41 positive specimens and 120 ELISA confirmed negative specimens were re-analyzed using RDT. The results of RDT showed only 35 positives from the total tested specimens including 29 which already positive by ELISA and RDT showing a sensitivity of 70.7% and specificity 95% with its kappa value 0.69 indicating a good agreement with ELISA.
Conclusion and recommendation: Rapid Ecotest® test of HBsAg has good agreement with ELISA but low sensitivity and high false negative value, so there should be an algorithm for HBV diagnostic methods when we used a rapid test kits.