Diagnostic performance of four hepatitis B surface antigen CE marked and one WHO prequalified rapid diagnostic tests in Uganda

Abstract

Hepatitis B is a global health problem and as a blood-borne disease, it remains a common cause of viral hepatitis infection, with possible long-term complications of cirrhosis and hepatocellular carcinoma in patients who develop chronic infection. In Uganda, rapid diagnostic tests (RDTs) are commonly used in the screening and diagnosis of viral hepatitis B. However there are few published studies available that can independently inform stakeholders of the performance of the different brands of hepatitis B surface antigen (HBsAg) RDTs currently available. This study aimed at evaluating the diagnostic performance of RDTs for the detection of HBsAg using donor blood samples in Kampala, Uganda. A cross-sectional study of five RDT brands was conducted at Uganda Blood Transfusion Service (UBTS) Nakasero, Kampala between April 2021 and May 2021, using residual serum blood samples collected from blood donations. Two hundred samples were screened for HBsAg using Chemiluminescent Microparticle Immunoassay (CMIA), and then tested using ELISA as the reference standard; the samples were then tested using One-Step, NOVA, Astracare, Accurate, and SD Bioline RDTs. The five brands of RDTs evaluated, all demonstrated a sensitivity of 93% (95% CI 93%- 93%) whereas the specificity ranged from 95% (95% CI 94.9%- 97.8%) for Astracare to 98% (95% CI 94.9%- 98.0%) for SD Bioline. Furthermore, the negative predictive value (NPV) ranged from 93.14% (95% CI 93.1% -93.3%) for Astracare and 93.33% (95% CI 93.1% -93.3%) for SD Bioline while positive predictive value (PPV) ranged from 94.89% (95% CI 94.9%-97.7%) for Astracare to 97.89% (95% CI 94.9%-98.0 %) for SD Bioline. The SD Bioline RDT had the overall best performance, with a high sensitivity, the overall best specificity, positive and negative predictive values. However, the sensitivity of all RDTs tested was below the WHO prequalification criteria, hence they cannot be used for blood bank testing. Nevertheless, the less expensive CE marked RDTs performed as well as the more expensive WHO prequalified RDT and can be used as a tool to achieve WHO-led campaign to eliminate HBV as a public health threat in these Uganda by 2030. Further research including sequencing and PCR is recommended to detect mutant HBsAg, specific viral genotypes, and occult hepatitis B which affect performance of RDTs.