Occult hepatitis B viral infection among blood donors in South–Eastern Nigeria

Abstract

Hepatitis B virus infection is endemic in many parts of sub-Saharan Africa including Nigeria. Occult hepatitis B virus infection (OBI) is a challenging clinical problem characterized by the absence of Hepatitis B surface Antigen (HBsAg) and low viral DNA load. We aimed at determining the prevalence of OBI among repeat blood donors in Abakaliki, south-eastern Nigeria. Of 113 informed consented repeat blood donors enrolled into the study, 12 donors (10·6%) tested positive to both serological HBsAg screening, anti-HBc total and hepatitis B virus (HBV) DNA Nested PCR tests. One donor (0·9%) tested HBsAg positive, anti-HBC positive but Nested PCR negative. All donors were negative for HIV 1 and 2 and HCV infections. Of the 100 HbsAg negative repeat blood donors, 8·0% (eight donors) were HBV DNA positive by nested PCR method and anti-HBc total positive by ELISA. The median viral load, determined by real time PCR-Taqman chemistry, in the OBI blood samples was 51 IU/ml compared to 228 IU/ml of the HBsAg screen positive donors. The observed OBI prevalence of 8·0% corroborated with high endemicity of HBV infection in Abakaliki. We therefore recommend routine HBV DNA testing by real time PCR method on all sero-negative blood donations in Abakaliki and for a similar policy to be evaluated across the sub-Saharan Africa.

Keywords:

• Occult hepatitis B infection
• OBI
• Blood donors
• Viral load
• Nested PCR
• Prevalence of OBI
• Real time PCR
• qPCR

Acknowledgements

We thank all the prospective blood donors that participated in this study. We are grateful to Miss Chimdi Precious Achi, Mr Sowechi Ebi and Miss Ijeoma Uzoma, staff of Safety Molecular Pathology Laboratory, who assisted in the laboratory work.