Endemic hepatitis B virus (HBV) among hospital in-patients in Bangladesh, including evidence of occult infection

Bangladesh is one of the worlds top ten burdened countries for viral hepatitis. We investigated an adult fever cohort (n=201) recruited in Dhaka, to determine the prevalence of hepatitis B virus (HBV) infection and to identify cases of occult hepatitis B infection (OBI). HBV exposure (anti-HBc) was documented in 72/201 (36%), and active HBV infection in 16/201 (8%), among whom 3 were defined as OBI (defined as detectable HBV DNA but negative HBsAg). Applying a target-enrichment sequencing pipeline to samples with HBV DNA >3.0log10 IU/ml, we obtained deep whole genome sequences for four cases, identifying genotypes A, C and D. Polymorphisms in the surface gene of the OBI case may account for the negative HBsAg status. We identified mutations associated with nucleos(t)ide analogue resistance, although the clinical significance in this cohort is not known. The high prevalence of HBV in this setting highlights the benefits of offering screening in hospital patients and the importance of HBV DNA testing of transfusion products to reduce the risk of transmission. In order to work towards international Sustainable Development Goal targets for HBV elimination, increased investment is required for diagnosis, treatment and prevention in Bangladesh.