Introduction Safe blood transfusions remain a challenge in Africa where sexually transmitted diseases (STIs) mainly hepatitis B virus (HBV), hepatitis C virus (HCV), syphilis and HIV are hyper-endemic. Amongst, HBV is ranked the 7th leading cause of annual global deaths. HBV has up to 10 genotypes (A-J) and all show uniqueness in prognosis, response to therapy and geographic distribution. In Africa, 30%. (A, D and E) of these genotypes have been identified circulating in different cohorts. Up to date, there is no data on the prevalence and molecular characterisation of HBV in blood donors in Botswana. The study aims to identify HBV genotypes circulating in Botswana blood donors and update its prevalence in comparison to other identified STIs in the cohort.
Methods A one-year cross-sectional study for consecutive hepatitis B surface antigen positive (HBsAg+) allogeneic blood donations confirmed using ELISA was done. HBV genome extraction was done using UltraSense DNA/RNA Kit followed by a 25 µl polymerase chain reaction (PCR) reaction made of master-mix containing SuperScript Platinum III polymerase and two primers Core-F and Werle-AS covering 2.1 kb region (PreS2, PreS1, S and part of Pol region). Big Dye sequencing chemistry was performed on 82% (41/50) successful PCR products of which 87.8% were successfully sequenced and genotyped.
Results Sub-genotype A1 (48%) serotype adw2 and D (52%) serotype ayw2 were confirmed in the cohort. Escape mutations A120L and 130 R in two genotype A samples were found associated with failure to vaccine and detection. Allogeneic donations at National Blood Transfusions Services in Botswana (NBTS) during study were 10 798. Prevalence of HBsAg+ was 0.92%. Co-infections confirmed were of Syphilis 1.72%, 1.54% for HIV and 0.43% for Hepatitis C. The total population’s age was normally distributed with mean of 29±1.7 years and a range of 44 years.
Conclusion Predominant genotype amongst Botswana blood donors is D3. There is a major concern to address STIs in Botswana much work is being done on HIV but the results reflect a burden of all STIs.