Treatment failure : if any of the following conditions apply : ( 1 ) lack of clinical improvement at 72h or more after starting therapy ; ( 2 ) persistent bacteraemia ( positive blood cultures on day 7 ) ; ( 3 ) therapy is discontinued early due to adverse effects or for some other reason based on clinical judgement ; ( 4 ) relapse of MRSA bacteraemia before the TOC visit ; ( 5 ) death for any reason before the TOC visit .