Antibiotics are nearly always given as soon as a patient is suspected to have a catheter-related bloodstream infection. However, this must occur after blood cultures are drawn, otherwise the culprit organism may not be identified. The most common organisms causing these infections are coagulase negative staphylococci such as "staphylococcus epidermidis". Infections resulting in bacteremia from "Staphylococcus aureus" require removal of the catheter and antibiotics. If the catheter is removed without giving antibiotics, 38% of people may still develop endocarditis. A systematic review has found evidence that in cancer patients, there may be no benefit to giving antibiotics before inserting a long-term central venous catheter to prevent Gram positive catheter-related infections. However, flushing the catheter with a solution containing an antibiotic and heparin may reduce catheter-related infections in this population, most likely when the risk of infection is high.