The latter group was further sub-divided into 13 occult HBV ( HBsAg-negative ) and 7 overt HBV ( HBsAg- positive ) patients .
O O O O O O O O O B-OrganismTaxon O B-ChemicalEntity O O O O B-OrganismTaxon O B-ChemicalEntity O O B-OrganismTaxon O