Fig. 4

Using reference strains from GenBank and 38 isolates (included mother and child pair) of our study a) Phylogenetic tree of full genome sequences generated using neighbour-joining method b) Mutation focused at “a” determinant region. a Using neighbour-joining method, displays sub-genotype of the full genome sequence of 38 isolates of our study, including one pair of a child and her mother. Blue circles and red circles represent genotype B and genotype C of the isolates from our study, respectively. The HBsAg positive child (CF20-0752 with blue triangle) and her mother (CV20-0752 with blue circle) were identified having the same sequence, confirming the HBV mother-to-child transmission. b shows the mutation at the “a” determinant region using 38 isolates from our study. Mutation at the “a” determinant was identified in 9 isolates (24.3%). No mutation at the “a” determinant region was detected in the pair of HBsAg-positive mother and child