Hepatitis B among immigrants from Myanmar: Genotypes and their clinical relevance.

Hepatitis B virus (HBV) from 76 adult immigrants in Australia from Myanmar was characterized to determine the prevalence of different HBV genotypes and subgenotypes. A mutational analysis was then performed to determine the presence of clinically significant mutations and correlate them to clinical outcomes. Initial genotyping revealed 68 patients with genotype C (89.5%) and eight patients with genotype B (10.5%). Phylogenetic analysis revealed the large majority of the genotype C infections were of subgenotype C1 (67/68). Sequencing of the HBV polymerase gene (and overlapping surface gene) revealed no mutations associated with antiviral resistance. HBV surface gene mutations were detected in 10 patients with subgenotype C1. HBV BCP/PC sequencing was obtained for 71/76 (93%) patients. BCP and/or PC mutations were identified in 57/71 (80%) of PCR positive patients. Treatment had been commenced for 15/76 (18%) patients, a further 26 untreated patients were in a stage of disease where HBV treatment would be considered standard of care. It was identified that genotype C1 is the predominant sub-genotype in this population. Genotype C is known to be associated with increased risk of development of HCC. This highlights the need for screening for HCC given the potential for the development of liver cancer. It was also identified that people with HBV were potentially not receiving optimal therapy in a timely fashion.

Genotypic profiles of hepatitis B in African immigrants and their clinical relevance.

Hepatitis B virus (HBV) from 40 adult African immigrants in Australia was characterized to determine the prevalence of different HBV genotypes and subgenotypes. A mutational analysis was then performed to determine the presence of clinically significant mutations and correlate them to clinical outcomes. Initial sequencing analysis revealed 13 with genotype A (32.5%), 13 with genotype D (32.5%), and 14 with genotype E (35%). Serology showed that 37 were HBeAg negative. Phylogenetic analysis identified a high prevalence (25%) of HBV subgenotype A1 in our cohort, a subgenotype which has been associated with more aggressive clinical disease. BCP/PC sequencing was obtained for 38 patients. BCP and/or PC mutations were identified in 36/38 (95%). The median viral load of all patients was 2995 IU/mL and most of the pathology results were within the normal range. Only one patient had an increased APRI score of 1.1 suggestive of cirrhosis. We present novel information on the HBV genotypes amongst the African population in Australia along with clinical correlates. The high prevalence of A1 subgenotype in this population supports the current Australian recommendation to commence hepatocellular carcinoma screening in Africans with chronic HBV from 20 years old.